Create pages from _content.gotmpl

Closes #12427
Closes #12485
Closes #6310
Closes #5074

24 files changed, 1598 insertions, 259 deletions

diff --git a/hugolib/config_test.go b/hugolib/config_test.go
index 8acf8b36e..aaba534f5 100644
--- a/hugolib/config_test.go
+++ b/hugolib/config_test.go
@@ -1144,7 +1144,7 @@ Home.
 
 	enConfig := b.H.Sites[0].conf
 	m, _ := enConfig.MediaTypes.Config.GetByType("text/html")
-	b.Assert(m.Suffixes(), qt.DeepEquals, []string{"html"})
+	b.Assert(m.Suffixes(), qt.DeepEquals, []string{"html", "htm"})
 
 	svConfig := b.H.Sites[1].conf
 	f, _ := svConfig.OutputFormats.Config.GetByName("html")
diff --git a/hugolib/content_map.go b/hugolib/content_map.go
index 62cabec51..b75ccdbcb 100644
--- a/hugolib/content_map.go
+++ b/hugolib/content_map.go
@@ -14,6 +14,7 @@
 package hugolib
 
 import (
+	"context"
 	"fmt"
 	"path"
 	"path/filepath"
@@ -23,10 +24,13 @@ import (
 	"github.com/bep/logg"
 	"github.com/gohugoio/hugo/common/hugio"
 	"github.com/gohugoio/hugo/common/paths"
+	"github.com/gohugoio/hugo/hugofs/files"
+	"github.com/gohugoio/hugo/hugolib/pagesfromdata"
 	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/source"
 
 	"github.com/gohugoio/hugo/resources/page"
+	"github.com/gohugoio/hugo/resources/page/pagemeta"
 	"github.com/gohugoio/hugo/resources/resource"
 
 	"github.com/gohugoio/hugo/hugofs"
@@ -51,9 +55,11 @@ type contentMapConfig struct {
 var _ contentNodeI = (*resourceSource)(nil)
 
 type resourceSource struct {
-	path   *paths.Path
-	opener hugio.OpenReadSeekCloser
-	fi     hugofs.FileMetaInfo
+	langIndex int
+	path      *paths.Path
+	opener    hugio.OpenReadSeekCloser
+	fi        hugofs.FileMetaInfo
+	rc        *pagemeta.ResourceConfig
 
 	r resource.Resource
 }
@@ -64,11 +70,7 @@ func (r resourceSource) clone() *resourceSource {
 }
 
 func (r *resourceSource) LangIndex() int {
-	if r.r != nil && r.isPage() {
-		return r.r.(*pageState).s.languagei
-	}
-
-	return r.fi.Meta().LangIndex
+	return r.langIndex
 }
 
 func (r *resourceSource) MarkStale() {
@@ -162,12 +164,13 @@ func (cfg contentMapConfig) getTaxonomyConfig(s string) (v viewName) {
 	return
 }
 
-func (m *pageMap) AddFi(fi hugofs.FileMetaInfo) error {
+func (m *pageMap) AddFi(fi hugofs.FileMetaInfo, buildConfig *BuildCfg) (pageCount uint64, resourceCount uint64, addErr error) {
 	if fi.IsDir() {
-		return nil
+		return
 	}
 
 	insertResource := func(fim hugofs.FileMetaInfo) error {
+		resourceCount++
 		pi := fi.Meta().PathInfo
 		key := pi.Base()
 		tree := m.treeResources
@@ -199,9 +202,9 @@ func (m *pageMap) AddFi(fi hugofs.FileMetaInfo) error {
 			}
 			key = pi.Base()
 
-			rs = &resourceSource{r: pageResource}
+			rs = &resourceSource{r: pageResource, langIndex: pageResource.s.languagei}
 		} else {
-			rs = &resourceSource{path: pi, opener: r, fi: fim}
+			rs = &resourceSource{path: pi, opener: r, fi: fim, langIndex: fim.Meta().LangIndex}
 		}
 
 		tree.InsertIntoValuesDimension(key, rs)
@@ -220,14 +223,27 @@ func (m *pageMap) AddFi(fi hugofs.FileMetaInfo) error {
 			},
 		))
 		if err := insertResource(fi); err != nil {
-			return err
+			addErr = err
+			return
 		}
+	case paths.PathTypeContentData:
+		pc, rc, err := m.addPagesFromGoTmplFi(fi, buildConfig)
+		pageCount += pc
+		resourceCount += rc
+		if err != nil {
+			addErr = err
+			return
+		}
+
 	default:
 		m.s.Log.Trace(logg.StringFunc(
 			func() string {
 				return fmt.Sprintf("insert bundle: %q", fi.Meta().Filename)
 			},
 		))
+
+		pageCount++
+
 		// A content file.
 		p, pi, err := m.s.h.newPage(
 			&pageMeta{
@@ -237,17 +253,164 @@ func (m *pageMap) AddFi(fi hugofs.FileMetaInfo) error {
 			},
 		)
 		if err != nil {
-			return err
+			addErr = err
+			return
 		}
 		if p == nil {
 			// Disabled page.
-			return nil
+			return
 		}
 
-		m.treePages.InsertWithLock(pi.Base(), p)
+		m.treePages.InsertIntoValuesDimensionWithLock(pi.Base(), p)
 
 	}
-	return nil
+	return
+}
+
+func (m *pageMap) addPagesFromGoTmplFi(fi hugofs.FileMetaInfo, buildConfig *BuildCfg) (pageCount uint64, resourceCount uint64, addErr error) {
+	meta := fi.Meta()
+	pi := meta.PathInfo
+
+	m.s.Log.Trace(logg.StringFunc(
+		func() string {
+			return fmt.Sprintf("insert pages from data file: %q", fi.Meta().Filename)
+		},
+	))
+
+	if !files.IsGoTmplExt(pi.Ext()) {
+		addErr = fmt.Errorf("unsupported data file extension %q", pi.Ext())
+		return
+	}
+
+	s := m.s.h.resolveSite(fi.Meta().Lang)
+	f := source.NewFileInfo(fi)
+	h := s.h
+
+	// Make sure the layouts are initialized.
+	if _, err := h.init.layouts.Do(context.Background()); err != nil {
+		addErr = err
+		return
+	}
+
+	contentAdapter := s.pageMap.treePagesFromTemplateAdapters.Get(pi.Base())
+	var rebuild bool
+	if contentAdapter != nil {
+		// Rebuild
+		contentAdapter = contentAdapter.CloneForGoTmpl(fi)
+		rebuild = true
+	} else {
+		contentAdapter = pagesfromdata.NewPagesFromTemplate(
+			pagesfromdata.PagesFromTemplateOptions{
+				GoTmplFi: fi,
+				Site:     s,
+				DepsFromSite: func(s page.Site) pagesfromdata.PagesFromTemplateDeps {
+					ss := s.(*Site)
+					return pagesfromdata.PagesFromTemplateDeps{
+						TmplFinder: ss.TextTmpl(),
+						TmplExec:   ss.Tmpl(),
+					}
+				},
+				DependencyManager: s.Conf.NewIdentityManager("pagesfromdata"),
+				Watching:          s.Conf.Watching(),
+				HandlePage: func(pt *pagesfromdata.PagesFromTemplate, pc *pagemeta.PageConfig) error {
+					s := pt.Site.(*Site)
+					if err := pc.Compile(pt.GoTmplFi.Meta().PathInfo.Base(), true, "", s.Log, s.conf.MediaTypes.Config); err != nil {
+						return err
+					}
+
+					ps, pi, err := h.newPage(
+						&pageMeta{
+							f: f,
+							s: s,
+							pageMetaParams: &pageMetaParams{
+								pageConfig: pc,
+							},
+						},
+					)
+					if err != nil {
+						return err
+					}
+
+					if ps == nil {
+						// Disabled page.
+						return nil
+					}
+
+					u, n, replaced := s.pageMap.treePages.InsertIntoValuesDimensionWithLock(pi.Base(), ps)
+
+					if h.isRebuild() {
+						if replaced {
+							pt.AddChange(n.GetIdentity())
+						} else {
+							pt.AddChange(u.GetIdentity())
+						}
+					}
+
+					return nil
+				},
+				HandleResource: func(pt *pagesfromdata.PagesFromTemplate, rc *pagemeta.ResourceConfig) error {
+					s := pt.Site.(*Site)
+					if err := rc.Compile(
+						pt.GoTmplFi.Meta().PathInfo.Base(),
+						s.Conf.PathParser(),
+						s.conf.MediaTypes.Config,
+					); err != nil {
+						return err
+					}
+
+					rs := &resourceSource{path: rc.PathInfo, rc: rc, opener: nil, fi: nil, langIndex: s.languagei}
+
+					_, n, replaced := s.pageMap.treeResources.InsertIntoValuesDimensionWithLock(rc.PathInfo.Base(), rs)
+
+					if h.isRebuild() && replaced {
+						pt.AddChange(n.GetIdentity())
+					}
+					return nil
+				},
+			},
+		)
+
+		s.pageMap.treePagesFromTemplateAdapters.Insert(pi.Base(), contentAdapter)
+
+	}
+
+	handleBuildInfo := func(s *Site, bi pagesfromdata.BuildInfo) {
+		resourceCount += bi.NumResourcesAdded
+		pageCount += bi.NumPagesAdded
+		s.handleContentAdapterChanges(bi, buildConfig)
+	}
+
+	bi, err := contentAdapter.Execute(context.Background())
+	if err != nil {
+		addErr = err
+		return
+	}
+	handleBuildInfo(s, bi)
+
+	if !rebuild && bi.EnableAllLanguages {
+		// Clone and insert the adapter for the other sites.
+		for _, ss := range s.h.Sites {
+			if s == ss {
+				continue
+			}
+
+			clone := contentAdapter.CloneForSite(ss)
+
+			// Make sure it gets executed for the first time.
+			bi, err := clone.Execute(context.Background())
+			if err != nil {
+				addErr = err
+				return
+			}
+			handleBuildInfo(ss, bi)
+
+			// Insert into the correct language tree so it get rebuilt on changes.
+			ss.pageMap.treePagesFromTemplateAdapters.Insert(pi.Base(), clone)
+
+		}
+	}
+
+	return
 }
 
 // The home page is represented with the zero string.
diff --git a/hugolib/content_map_page.go b/hugolib/content_map_page.go
index a0bff7472..5758cb6f6 100644
--- a/hugolib/content_map_page.go
+++ b/hugolib/content_map_page.go
@@ -34,7 +34,9 @@ import (
 	"github.com/gohugoio/hugo/common/types"
 	"github.com/gohugoio/hugo/hugofs/files"
 	"github.com/gohugoio/hugo/hugolib/doctree"
+	"github.com/gohugoio/hugo/hugolib/pagesfromdata"
 	"github.com/gohugoio/hugo/identity"
+	"github.com/gohugoio/hugo/media"
 	"github.com/gohugoio/hugo/output"
 	"github.com/gohugoio/hugo/resources"
 	"github.com/spf13/cast"
@@ -100,6 +102,8 @@ type pageMap struct {
 	cacheContentPlain      *dynacache.Partition[string, *resources.StaleValue[contentPlainPlainWords]]
 	contentTableOfContents *dynacache.Partition[string, *resources.StaleValue[contentTableOfContents]]
 
+	contentDataFileSeenItems *maps.Cache[string, map[uint64]bool]
+
 	cfg contentMapConfig
 }
 
@@ -122,6 +126,10 @@ type pageTrees struct {
 	// This tree contains all taxonomy entries, e.g "/tags/blue/page1"
 	treeTaxonomyEntries *doctree.TreeShiftTree[*weightedContentNode]
 
+	// Stores the state for _content.gotmpl files.
+	// Mostly releveant for rebuilds.
+	treePagesFromTemplateAdapters *doctree.TreeShiftTree[*pagesfromdata.PagesFromTemplate]
+
 	// A slice of the resource trees.
 	resourceTrees doctree.MutableTrees
 }
@@ -222,6 +230,7 @@ func (t pageTrees) Shape(d, v int) *pageTrees {
 	t.treePages = t.treePages.Shape(d, v)
 	t.treeResources = t.treeResources.Shape(d, v)
 	t.treeTaxonomyEntries = t.treeTaxonomyEntries.Shape(d, v)
+	t.treePagesFromTemplateAdapters = t.treePagesFromTemplateAdapters.Shape(d, v)
 	t.createMutableTrees()
 
 	return &t
@@ -587,9 +596,9 @@ func (m *pageMap) getOrCreateResourcesForPage(ps *pageState) resource.Resources
 
 		sort.SliceStable(res, lessFunc)
 
-		if len(ps.m.pageConfig.Resources) > 0 {
+		if len(ps.m.pageConfig.ResourcesMeta) > 0 {
 			for i, r := range res {
-				res[i] = resources.CloneWithMetadataIfNeeded(ps.m.pageConfig.Resources, r)
+				res[i] = resources.CloneWithMetadataFromMapIfNeeded(ps.m.pageConfig.ResourcesMeta, r)
 			}
 			sort.SliceStable(res, lessFunc)
 		}
@@ -667,12 +676,13 @@ type contentNodeShifter struct {
 	numLanguages int
 }
 
-func (s *contentNodeShifter) Delete(n contentNodeI, dimension doctree.Dimension) (bool, bool) {
+func (s *contentNodeShifter) Delete(n contentNodeI, dimension doctree.Dimension) (contentNodeI, bool, bool) {
 	lidx := dimension[0]
 	switch v := n.(type) {
 	case contentNodeIs:
-		resource.MarkStale(v[lidx])
-		wasDeleted := v[lidx] != nil
+		deleted := v[lidx]
+		resource.MarkStale(deleted)
+		wasDeleted := deleted != nil
 		v[lidx] = nil
 		isEmpty := true
 		for _, vv := range v {
@@ -681,10 +691,11 @@ func (s *contentNodeShifter) Delete(n contentNodeI, dimension doctree.Dimension)
 				break
 			}
 		}
-		return wasDeleted, isEmpty
+		return deleted, wasDeleted, isEmpty
 	case resourceSources:
-		resource.MarkStale(v[lidx])
-		wasDeleted := v[lidx] != nil
+		deleted := v[lidx]
+		resource.MarkStale(deleted)
+		wasDeleted := deleted != nil
 		v[lidx] = nil
 		isEmpty := true
 		for _, vv := range v {
@@ -693,19 +704,19 @@ func (s *contentNodeShifter) Delete(n contentNodeI, dimension doctree.Dimension)
 				break
 			}
 		}
-		return wasDeleted, isEmpty
+		return deleted, wasDeleted, isEmpty
 	case *resourceSource:
 		if lidx != v.LangIndex() {
-			return false, false
+			return nil, false, false
 		}
 		resource.MarkStale(v)
-		return true, true
+		return v, true, true
 	case *pageState:
 		if lidx != v.s.languagei {
-			return false, false
+			return nil, false, false
 		}
 		resource.MarkStale(v)
-		return true, true
+		return v, true, true
 	default:
 		panic(fmt.Sprintf("unknown type %T", n))
 	}
@@ -778,7 +789,7 @@ func (s *contentNodeShifter) ForEeachInDimension(n contentNodeI, d int, f func(c
 	}
 }
 
-func (s *contentNodeShifter) InsertInto(old, new contentNodeI, dimension doctree.Dimension) contentNodeI {
+func (s *contentNodeShifter) InsertInto(old, new contentNodeI, dimension doctree.Dimension) (contentNodeI, contentNodeI, bool) {
 	langi := dimension[doctree.DimensionLanguage.Index()]
 	switch vv := old.(type) {
 	case *pageState:
@@ -787,37 +798,39 @@ func (s *contentNodeShifter) InsertInto(old, new contentNodeI, dimension doctree
 			panic(fmt.Sprintf("unknown type %T", new))
 		}
 		if vv.s.languagei == newp.s.languagei && newp.s.languagei == langi {
-			return new
+			return new, vv, true
 		}
 		is := make(contentNodeIs, s.numLanguages)
 		is[vv.s.languagei] = old
 		is[langi] = new
-		return is
+		return is, old, false
 	case contentNodeIs:
+		oldv := vv[langi]
 		vv[langi] = new
-		return vv
+		return vv, oldv, oldv != nil
 	case resourceSources:
+		oldv := vv[langi]
 		vv[langi] = new.(*resourceSource)
-		return vv
+		return vv, oldv, oldv != nil
 	case *resourceSource:
 		newp, ok := new.(*resourceSource)
 		if !ok {
 			panic(fmt.Sprintf("unknown type %T", new))
 		}
 		if vv.LangIndex() == newp.LangIndex() && newp.LangIndex() == langi {
-			return new
+			return new, vv, true
 		}
 		rs := make(resourceSources, s.numLanguages)
 		rs[vv.LangIndex()] = vv
 		rs[langi] = newp
-		return rs
+		return rs, vv, false
 
 	default:
 		panic(fmt.Sprintf("unknown type %T", old))
 	}
 }
 
-func (s *contentNodeShifter) Insert(old, new contentNodeI) contentNodeI {
+func (s *contentNodeShifter) Insert(old, new contentNodeI) (contentNodeI, contentNodeI, bool) {
 	switch vv := old.(type) {
 	case *pageState:
 		newp, ok := new.(*pageState)
@@ -828,12 +841,12 @@ func (s *contentNodeShifter) Insert(old, new contentNodeI) contentNodeI {
 			if newp != old {
 				resource.MarkStale(old)
 			}
-			return new
+			return new, vv, true
 		}
 		is := make(contentNodeIs, s.numLanguages)
 		is[newp.s.languagei] = new
 		is[vv.s.languagei] = old
-		return is
+		return is, old, false
 	case contentNodeIs:
 		newp, ok := new.(*pageState)
 		if !ok {
@@ -844,7 +857,7 @@ func (s *contentNodeShifter) Insert(old, new contentNodeI) contentNodeI {
 			resource.MarkStale(oldp)
 		}
 		vv[newp.s.languagei] = new
-		return vv
+		return vv, oldp, oldp != nil
 	case *resourceSource:
 		newp, ok := new.(*resourceSource)
 		if !ok {
@@ -854,12 +867,12 @@ func (s *contentNodeShifter) Insert(old, new contentNodeI) contentNodeI {
 			if vv != newp {
 				resource.MarkStale(vv)
 			}
-			return new
+			return new, vv, true
 		}
 		rs := make(resourceSources, s.numLanguages)
 		rs[newp.LangIndex()] = newp
 		rs[vv.LangIndex()] = vv
-		return rs
+		return rs, vv, false
 	case resourceSources:
 		newp, ok := new.(*resourceSource)
 		if !ok {
@@ -870,7 +883,7 @@ func (s *contentNodeShifter) Insert(old, new contentNodeI) contentNodeI {
 			resource.MarkStale(oldp)
 		}
 		vv[newp.LangIndex()] = newp
-		return vv
+		return vv, oldp, oldp != nil
 	default:
 		panic(fmt.Sprintf("unknown type %T", old))
 	}
@@ -890,6 +903,8 @@ func newPageMap(i int, s *Site, mcache *dynacache.Cache, pageTrees *pageTrees) *
 		cacheContentPlain:      dynacache.GetOrCreatePartition[string, *resources.StaleValue[contentPlainPlainWords]](mcache, fmt.Sprintf("/cont/pla/%d", i), dynacache.OptionsPartition{Weight: 70, ClearWhen: dynacache.ClearOnChange}),
 		contentTableOfContents: dynacache.GetOrCreatePartition[string, *resources.StaleValue[contentTableOfContents]](mcache, fmt.Sprintf("/cont/toc/%d", i), dynacache.OptionsPartition{Weight: 70, ClearWhen: dynacache.ClearOnChange}),
 
+		contentDataFileSeenItems: maps.NewCache[string, map[uint64]bool](),
+
 		cfg: contentMapConfig{
 			lang:                 s.Lang(),
 			taxonomyConfig:       taxonomiesConfig.Values(),
@@ -960,8 +975,6 @@ type contentTreeReverseIndexMap struct {
 
 type sitePagesAssembler struct {
 	*Site
-	watching        bool
-	incomingChanges *whatChanged
 	assembleChanges *whatChanged
 	ctx             context.Context
 }
@@ -1080,6 +1093,7 @@ func (h *HugoSites) resolveAndClearStateForIdentities(
 	// 1. Handle the cache busters first, as those may produce identities for the page reset step.
 	// 2. Then reset the page outputs, which may mark some resources as stale.
 	// 3. Then GC the cache.
+	// TOOD1
 	if cachebuster != nil {
 		if err := loggers.TimeTrackfn(func() (logg.LevelLogger, error) {
 			ll := l.WithField("substep", "gc dynacache cachebuster")
@@ -1125,6 +1139,33 @@ func (h *HugoSites) resolveAndClearStateForIdentities(
 	}
 	changes = changes[:n]
 
+	if h.pageTrees.treePagesFromTemplateAdapters.LenRaw() > 0 {
+		if err := loggers.TimeTrackfn(func() (logg.LevelLogger, error) {
+			ll := l.WithField("substep", "resolve content adapter change set").WithField("changes", len(changes))
+			checkedCount := 0
+			matchCount := 0
+			depsFinder := identity.NewFinder(identity.FinderConfig{})
+
+			h.pageTrees.treePagesFromTemplateAdapters.WalkPrefixRaw(doctree.LockTypeRead, "",
+				func(s string, n *pagesfromdata.PagesFromTemplate) (bool, error) {
+					for _, id := range changes {
+						checkedCount++
+						if r := depsFinder.Contains(id, n.DependencyManager, 2); r > identity.FinderNotFound {
+							n.MarkStale()
+							matchCount++
+							break
+						}
+					}
+					return false, nil
+				})
+
+			ll = ll.WithField("checked", checkedCount).WithField("matches", matchCount)
+			return ll, nil
+		}); err != nil {
+			return err
+		}
+	}
+
 	if err := loggers.TimeTrackfn(func() (logg.LevelLogger, error) {
 		// changesLeft: The IDs that the pages is dependent on.
 		// changesRight: The IDs that the pages depend on.
@@ -1269,6 +1310,7 @@ func (sa *sitePagesAssembler) applyAggregates() error {
 	rw := pw.Extend()
 	rw.Tree = sa.pageMap.treeResources
 	sa.lastmod = time.Time{}
+	rebuild := sa.s.h.isRebuild()
 
 	pw.Handle = func(keyPage string, n contentNodeI, match doctree.DimensionFlag) (bool, error) {
 		pageBundle := n.(*pageState)
@@ -1289,7 +1331,7 @@ func (sa *sitePagesAssembler) applyAggregates() error {
 			// Home page gets it's cascade from the site config.
 			cascade = sa.conf.Cascade.Config
 
-			if pageBundle.m.pageConfig.Cascade == nil {
+			if pageBundle.m.pageConfig.CascadeCompiled == nil {
 				// Pass the site cascade downwards.
 				pw.WalkContext.Data().Insert(keyPage, cascade)
 			}
@@ -1300,18 +1342,20 @@ func (sa *sitePagesAssembler) applyAggregates() error {
 			}
 		}
 
-		if (pageBundle.IsHome() || pageBundle.IsSection()) && pageBundle.m.setMetaPostCount > 0 {
-			oldDates := pageBundle.m.pageConfig.Dates
+		if rebuild {
+			if (pageBundle.IsHome() || pageBundle.IsSection()) && pageBundle.m.setMetaPostCount > 0 {
+				oldDates := pageBundle.m.pageConfig.Dates
 
-			// We need to wait until after the walk to determine if any of the dates have changed.
-			pw.WalkContext.AddPostHook(
-				func() error {
-					if oldDates != pageBundle.m.pageConfig.Dates {
-						sa.assembleChanges.Add(pageBundle)
-					}
-					return nil
-				},
-			)
+				// We need to wait until after the walk to determine if any of the dates have changed.
+				pw.WalkContext.AddPostHook(
+					func() error {
+						if oldDates != pageBundle.m.pageConfig.Dates {
+							sa.assembleChanges.Add(pageBundle)
+						}
+						return nil
+					},
+				)
+			}
 		}
 
 		// Combine the cascade map with front matter.
@@ -1321,15 +1365,15 @@ func (sa *sitePagesAssembler) applyAggregates() error {
 
 		// We receive cascade values from above. If this leads to a change compared
 		// to the previous value, we need to mark the page and its dependencies as changed.
-		if pageBundle.m.setMetaPostCascadeChanged {
+		if rebuild && pageBundle.m.setMetaPostCascadeChanged {
 			sa.assembleChanges.Add(pageBundle)
 		}
 
 		const eventName = "dates"
 		if n.isContentNodeBranch() {
-			if pageBundle.m.pageConfig.Cascade != nil {
+			if pageBundle.m.pageConfig.CascadeCompiled != nil {
 				// Pass it down.
-				pw.WalkContext.Data().Insert(keyPage, pageBundle.m.pageConfig.Cascade)
+				pw.WalkContext.Data().Insert(keyPage, pageBundle.m.pageConfig.CascadeCompiled)
 			}
 
 			wasZeroDates := pageBundle.m.pageConfig.Dates.IsAllDatesZero()
@@ -1430,9 +1474,9 @@ func (sa *sitePagesAssembler) applyAggregatesToTaxonomiesAndTerms() error {
 				p := n.(*pageState)
 				if p.Kind() != kinds.KindTerm {
 					// The other kinds were handled in applyAggregates.
-					if p.m.pageConfig.Cascade != nil {
+					if p.m.pageConfig.CascadeCompiled != nil {
 						// Pass it down.
-						pw.WalkContext.Data().Insert(s, p.m.pageConfig.Cascade)
+						pw.WalkContext.Data().Insert(s, p.m.pageConfig.CascadeCompiled)
 					}
 				}
 
@@ -1553,7 +1597,7 @@ func (sa *sitePagesAssembler) assembleTermsAndTranslations() error {
 							singular: viewName.singular,
 							s:        sa.Site,
 							pathInfo: pi,
-							pageMetaParams: pageMetaParams{
+							pageMetaParams: &pageMetaParams{
 								pageConfig: &pagemeta.PageConfig{
 									Kind: kinds.KindTerm,
 								},
@@ -1615,13 +1659,13 @@ func (sa *sitePagesAssembler) assembleResources() error {
 			targetPaths := ps.targetPaths()
 			baseTarget := targetPaths.SubResourceBaseTarget
 			duplicateResourceFiles := true
-			if ps.m.pageConfig.IsGoldmark {
+			if ps.m.pageConfig.ContentMediaType.IsMarkdown() {
 				duplicateResourceFiles = ps.s.ContentSpec.Converters.GetMarkupConfig().Goldmark.DuplicateResourceFiles
 			}
 
 			duplicateResourceFiles = duplicateResourceFiles || ps.s.Conf.IsMultihost()
 
-			sa.pageMap.forEachResourceInPage(
+			err := sa.pageMap.forEachResourceInPage(
 				ps, lockType,
 				!duplicateResourceFiles,
 				func(resourceKey string, n contentNodeI, match doctree.DimensionFlag) (bool, error) {
@@ -1647,6 +1691,23 @@ func (sa *sitePagesAssembler) assembleResources() error {
 
 					}
 
+					if rs.rc != nil && rs.rc.Content.IsResourceValue() {
+						if rs.rc.Name == "" {
+							rs.rc.Name = relPathOriginal
+						}
+						r, err := ps.m.s.ResourceSpec.NewResourceWrapperFromResourceConfig(rs.rc)
+						if err != nil {
+							return false, err
+						}
+						rs.r = r
+						return false, nil
+					}
+
+					var mt media.Type
+					if rs.rc != nil {
+						mt = rs.rc.ContentMediaType
+					}
+
 					rd := resources.ResourceSourceDescriptor{
 						OpenReadSeekCloser:   rs.opener,
 						Path:                 rs.path,
@@ -1657,8 +1718,23 @@ func (sa *sitePagesAssembler) assembleResources() error {
 						BasePathTargetPath:   baseTarget,
 						NameNormalized:       relPath,
 						NameOriginal:         relPathOriginal,
+						MediaType:            mt,
 						LazyPublish:          !ps.m.pageConfig.Build.PublishResources,
 					}
+
+					if rs.rc != nil {
+						rc := rs.rc
+						rd.OpenReadSeekCloser = rc.Content.ValueAsOpenReadSeekCloser()
+						if rc.Name != "" {
+							rd.NameNormalized = rc.Name
+							rd.NameOriginal = rc.Name
+						}
+						if rc.Title != "" {
+							rd.Title = rc.Title
+						}
+						rd.Params = rc.Params
+					}
+
 					r, err := ps.m.s.ResourceSpec.NewResource(rd)
 					if err != nil {
 						return false, err
@@ -1668,7 +1744,7 @@ func (sa *sitePagesAssembler) assembleResources() error {
 				},
 			)
 
-			return false, nil
+			return false, err
 		},
 	}
 
@@ -1775,7 +1851,7 @@ func (sa *sitePagesAssembler) addStandalonePages() error {
 		m := &pageMeta{
 			s:        s,
 			pathInfo: s.Conf.PathParser().Parse(files.ComponentFolderContent, key+f.MediaType.FirstSuffix.FullSuffix),
-			pageMetaParams: pageMetaParams{
+			pageMetaParams: &pageMetaParams{
 				pageConfig: &pagemeta.PageConfig{
 					Kind: kind,
 				},
@@ -1893,7 +1969,7 @@ func (sa *sitePagesAssembler) addMissingRootSections() error {
 		m := &pageMeta{
 			s:        sa.Site,
 			pathInfo: p,
-			pageMetaParams: pageMetaParams{
+			pageMetaParams: &pageMetaParams{
 				pageConfig: &pagemeta.PageConfig{
 					Kind: kinds.KindHome,
 				},
@@ -1903,7 +1979,7 @@ func (sa *sitePagesAssembler) addMissingRootSections() error {
 		if err != nil {
 			return err
 		}
-		w.Tree.InsertWithLock(p.Base(), n)
+		w.Tree.InsertIntoValuesDimensionWithLock(p.Base(), n)
 		sa.home = n
 	}
 
@@ -1926,7 +2002,7 @@ func (sa *sitePagesAssembler) addMissingTaxonomies() error {
 			m := &pageMeta{
 				s:        sa.Site,
 				pathInfo: sa.Conf.PathParser().Parse(files.ComponentFolderContent, key+"/_index.md"),
-				pageMetaParams: pageMetaParams{
+				pageMetaParams: &pageMetaParams{
 					pageConfig: &pagemeta.PageConfig{
 						Kind: kinds.KindTaxonomy,
 					},
diff --git a/hugolib/doctree/nodeshiftree_test.go b/hugolib/doctree/nodeshiftree_test.go
index 313be0bc4..ac89037ac 100644
--- a/hugolib/doctree/nodeshiftree_test.go
+++ b/hugolib/doctree/nodeshiftree_test.go
@@ -173,7 +173,7 @@ func TestTreeInsert(t *testing.T) {
 	c.Assert(tree.Get("/notfound"), qt.IsNil)
 
 	ab2 := &testValue{ID: "/a/b", Lang: 0}
-	v, ok := tree.InsertIntoValuesDimension("/a/b", ab2)
+	v, _, ok := tree.InsertIntoValuesDimension("/a/b", ab2)
 	c.Assert(ok, qt.IsTrue)
 	c.Assert(v, qt.DeepEquals, ab2)
 
@@ -239,16 +239,16 @@ func (s *testShifter) ForEeachInDimension(n *testValue, d int, f func(n *testVal
 	f(n)
 }
 
-func (s *testShifter) Insert(old, new *testValue) *testValue {
-	return new
+func (s *testShifter) Insert(old, new *testValue) (*testValue, *testValue, bool) {
+	return new, old, true
 }
 
-func (s *testShifter) InsertInto(old, new *testValue, dimension doctree.Dimension) *testValue {
-	return new
+func (s *testShifter) InsertInto(old, new *testValue, dimension doctree.Dimension) (*testValue, *testValue, bool) {
+	return new, old, true
 }
 
-func (s *testShifter) Delete(n *testValue, dimension doctree.Dimension) (bool, bool) {
-	return true, true
+func (s *testShifter) Delete(n *testValue, dimension doctree.Dimension) (*testValue, bool, bool) {
+	return nil, true, true
 }
 
 func (s *testShifter) Shift(n *testValue, dimension doctree.Dimension, exact bool) (*testValue, bool, doctree.DimensionFlag) {
diff --git a/hugolib/doctree/nodeshifttree.go b/hugolib/doctree/nodeshifttree.go
index 1c1175305..36382c2d7 100644
--- a/hugolib/doctree/nodeshifttree.go
+++ b/hugolib/doctree/nodeshifttree.go
@@ -38,16 +38,18 @@ type (
 
 		// Insert inserts new into the tree into the dimension it provides.
 		// It may replace old.
-		// It returns a T (can be the same as old).
-		Insert(old, new T) T
+		// It returns the updated and existing T
+		// and a bool indicating if an existing record is updated.
+		Insert(old, new T) (T, T, bool)
 
 		// Insert inserts new into the given dimension.
 		// It may replace old.
-		// It returns a T (can be the same as old).
-		InsertInto(old, new T, dimension Dimension) T
+		// It returns the updated and existing T
+		// and a bool indicating if an existing record is updated.
+		InsertInto(old, new T, dimension Dimension) (T, T, bool)
 
-		// Delete deletes T from the given dimension and returns whether the dimension was deleted and if  it's empty after the delete.
-		Delete(v T, dimension Dimension) (bool, bool)
+		// Delete deletes T from the given dimension and returns the deleted T and whether the dimension was deleted and if  it's empty after the delete.
+		Delete(v T, dimension Dimension) (T, bool, bool)
 
 		// Shift shifts T into the given dimension
 		// and returns the shifted T and a bool indicating if the shift was successful and
@@ -81,7 +83,11 @@ func New[T any](cfg Config[T]) *NodeShiftTree[T] {
 	}
 }
 
-func (r *NodeShiftTree[T]) Delete(key string) {
+func (r *NodeShiftTree[T]) Delete(key string) (T, bool) {
+	return r.delete(key)
+}
+
+func (r *NodeShiftTree[T]) DeleteRaw(key string) {
 	r.delete(key)
 }
 
@@ -103,23 +109,24 @@ func (r *NodeShiftTree[T]) DeletePrefix(prefix string) int {
 		return false
 	})
 	for _, key := range keys {
-		if ok := r.delete(key); ok {
+		if _, ok := r.delete(key); ok {
 			count++
 		}
 	}
 	return count
 }
 
-func (r *NodeShiftTree[T]) delete(key string) bool {
+func (r *NodeShiftTree[T]) delete(key string) (T, bool) {
 	var wasDeleted bool
+	var deleted T
 	if v, ok := r.tree.Get(key); ok {
 		var isEmpty bool
-		wasDeleted, isEmpty = r.shifter.Delete(v.(T), r.dims)
+		deleted, wasDeleted, isEmpty = r.shifter.Delete(v.(T), r.dims)
 		if isEmpty {
 			r.tree.Delete(key)
 		}
 	}
-	return wasDeleted
+	return deleted, wasDeleted
 }
 
 func (t *NodeShiftTree[T]) DeletePrefixAll(prefix string) int {
@@ -141,22 +148,33 @@ func (t *NodeShiftTree[T]) Increment(d int) *NodeShiftTree[T] {
 	return t.Shape(d, t.dims[d]+1)
 }
 
-func (r *NodeShiftTree[T]) InsertIntoCurrentDimension(s string, v T) (T, bool) {
+func (r *NodeShiftTree[T]) InsertIntoCurrentDimension(s string, v T) (T, T, bool) {
 	s = mustValidateKey(cleanKey(s))
+	var (
+		updated  bool
+		existing T
+	)
 	if vv, ok := r.tree.Get(s); ok {
-		v = r.shifter.InsertInto(vv.(T), v, r.dims)
+		v, existing, updated = r.shifter.InsertInto(vv.(T), v, r.dims)
 	}
 	r.tree.Insert(s, v)
-	return v, true
+	return v, existing, updated
 }
 
-func (r *NodeShiftTree[T]) InsertIntoValuesDimension(s string, v T) (T, bool) {
+// InsertIntoValuesDimension inserts v into the tree at the given key and the
+// dimension defined by the value.
+// It returns the updated and existing T and a bool indicating if an existing record is updated.
+func (r *NodeShiftTree[T]) InsertIntoValuesDimension(s string, v T) (T, T, bool) {
 	s = mustValidateKey(cleanKey(s))
+	var (
+		updated  bool
+		existing T
+	)
 	if vv, ok := r.tree.Get(s); ok {
-		v = r.shifter.Insert(vv.(T), v)
+		v, existing, updated = r.shifter.Insert(vv.(T), v)
 	}
 	r.tree.Insert(s, v)
-	return v, true
+	return v, existing, updated
 }
 
 func (r *NodeShiftTree[T]) InsertRawWithLock(s string, v any) (any, bool) {
@@ -165,7 +183,8 @@ func (r *NodeShiftTree[T]) InsertRawWithLock(s string, v any) (any, bool) {
 	return r.tree.Insert(s, v)
 }
 
-func (r *NodeShiftTree[T]) InsertWithLock(s string, v T) (T, bool) {
+// It returns the updated and existing T and a bool indicating if an existing record is updated.
+func (r *NodeShiftTree[T]) InsertIntoValuesDimensionWithLock(s string, v T) (T, T, bool) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	return r.InsertIntoValuesDimension(s, v)
diff --git a/hugolib/doctree/simpletree.go b/hugolib/doctree/simpletree.go
index 811a7ff80..2193c08f6 100644
--- a/hugolib/doctree/simpletree.go
+++ b/hugolib/doctree/simpletree.go
@@ -28,12 +28,12 @@ type Tree[T any] interface {
 }
 
 // NewSimpleTree creates a new SimpleTree.
-func NewSimpleTree[T any]() *SimpleTree[T] {
+func NewSimpleTree[T comparable]() *SimpleTree[T] {
 	return &SimpleTree[T]{tree: radix.New()}
 }
 
 // SimpleTree is a thread safe radix tree that holds T.
-type SimpleTree[T any] struct {
+type SimpleTree[T comparable] struct {
 	mu   sync.RWMutex
 	tree *radix.Tree
 	zero T
@@ -67,16 +67,23 @@ func (tree *SimpleTree[T]) Insert(s string, v T) T {
 	return v
 }
 
-func (tree *SimpleTree[T]) WalkPrefix(lockType LockType, s string, f func(s string, v T) (bool, error)) error {
+func (tree *SimpleTree[T]) Lock(lockType LockType) func() {
 	switch lockType {
 	case LockTypeNone:
+		return func() {}
 	case LockTypeRead:
 		tree.mu.RLock()
-		defer tree.mu.RUnlock()
+		return tree.mu.RUnlock
 	case LockTypeWrite:
 		tree.mu.Lock()
-		defer tree.mu.Unlock()
+		return tree.mu.Unlock
 	}
+	return func() {}
+}
+
+func (tree *SimpleTree[T]) WalkPrefix(lockType LockType, s string, f func(s string, v T) (bool, error)) error {
+	commit := tree.Lock(lockType)
+	defer commit()
 	var err error
 	tree.tree.WalkPrefix(s, func(s string, v any) bool {
 		var b bool
diff --git a/hugolib/doctree/support.go b/hugolib/doctree/support.go
index 8083df127..adcc3b06c 100644
--- a/hugolib/doctree/support.go
+++ b/hugolib/doctree/support.go
@@ -113,7 +113,7 @@ type LockType int
 
 // MutableTree is a tree that can be modified.
 type MutableTree interface {
-	Delete(key string)
+	DeleteRaw(key string)
 	DeleteAll(key string)
 	DeletePrefix(prefix string) int
 	DeletePrefixAll(prefix string) int
@@ -140,9 +140,9 @@ var _ MutableTree = MutableTrees(nil)
 
 type MutableTrees []MutableTree
 
-func (t MutableTrees) Delete(key string) {
+func (t MutableTrees) DeleteRaw(key string) {
 	for _, tree := range t {
-		tree.Delete(key)
+		tree.DeleteRaw(key)
 	}
 }
 
diff --git a/hugolib/doctree/treeshifttree.go b/hugolib/doctree/treeshifttree.go
index f8a6d360b..cd13b9f61 100644
--- a/hugolib/doctree/treeshifttree.go
+++ b/hugolib/doctree/treeshifttree.go
@@ -15,18 +15,21 @@ package doctree
 
 var _ Tree[string] = (*TreeShiftTree[string])(nil)
 
-type TreeShiftTree[T any] struct {
+type TreeShiftTree[T comparable] struct {
 	// This tree is shiftable in one dimension.
 	d int
 
 	// The value of the current dimension.
 	v int
 
+	// The zero value of T.
+	zero T
+
 	// Will be of length equal to the length of the dimension.
 	trees []*SimpleTree[T]
 }
 
-func NewTreeShiftTree[T any](d, length int) *TreeShiftTree[T] {
+func NewTreeShiftTree[T comparable](d, length int) *TreeShiftTree[T] {
 	if length <= 0 {
 		panic("length must be > 0")
 	}
@@ -52,6 +55,17 @@ func (t *TreeShiftTree[T]) Get(s string) T {
 	return t.trees[t.v].Get(s)
 }
 
+func (t *TreeShiftTree[T]) DeleteAllFunc(s string, f func(s string, v T) bool) {
+	for _, tt := range t.trees {
+		if v := tt.Get(s); v != t.zero {
+			if f(s, v) {
+				// Delete.
+				tt.tree.Delete(s)
+			}
+		}
+	}
+}
+
 func (t *TreeShiftTree[T]) LongestPrefix(s string) (string, T) {
 	return t.trees[t.v].LongestPrefix(s)
 }
@@ -60,42 +74,41 @@ func (t *TreeShiftTree[T]) Insert(s string, v T) T {
 	return t.trees[t.v].Insert(s, v)
 }
 
+func (t *TreeShiftTree[T]) Lock(lockType LockType) func() {
+	return t.trees[t.v].Lock(lockType)
+}
+
 func (t *TreeShiftTree[T]) WalkPrefix(lockType LockType, s string, f func(s string, v T) (bool, error)) error {
 	return t.trees[t.v].WalkPrefix(lockType, s, f)
 }
 
-func (t *TreeShiftTree[T]) Delete(key string) {
+func (t *TreeShiftTree[T]) WalkPrefixRaw(lockType LockType, s string, f func(s string, v T) (bool, error)) error {
 	for _, tt := range t.trees {
-		tt.tree.Delete(key)
+		if err := tt.WalkPrefix(lockType, s, f); err != nil {
+			return err
+		}
 	}
+	return nil
 }
 
-func (t *TreeShiftTree[T]) DeletePrefix(prefix string) int {
+func (t *TreeShiftTree[T]) LenRaw() int {
 	var count int
 	for _, tt := range t.trees {
-		count += tt.tree.DeletePrefix(prefix)
+		count += tt.tree.Len()
 	}
 	return count
 }
 
-func (t *TreeShiftTree[T]) Lock(writable bool) (commit func()) {
-	if writable {
-		for _, tt := range t.trees {
-			tt.mu.Lock()
-		}
-		return func() {
-			for _, tt := range t.trees {
-				tt.mu.Unlock()
-			}
-		}
+func (t *TreeShiftTree[T]) Delete(key string) {
+	for _, tt := range t.trees {
+		tt.tree.Delete(key)
 	}
+}
 
+func (t *TreeShiftTree[T]) DeletePrefix(prefix string) int {
+	var count int
 	for _, tt := range t.trees {
-		tt.mu.RLock()
-	}
-	return func() {
-		for _, tt := range t.trees {
-			tt.mu.RUnlock()
-		}
+		count += tt.tree.DeletePrefix(prefix)
 	}
+	return count
 }
diff --git a/hugolib/hugo_sites.go b/hugolib/hugo_sites.go
index cf939ba92..61a07812d 100644
--- a/hugolib/hugo_sites.go
+++ b/hugolib/hugo_sites.go
@@ -111,6 +111,24 @@ func (h *HugoSites) ShouldSkipFileChangeEvent(ev fsnotify.Event) bool {
 	return h.skipRebuildForFilenames[ev.Name]
 }
 
+func (h *HugoSites) isRebuild() bool {
+	return h.buildCounter.Load() > 0
+}
+
+func (h *HugoSites) resolveSite(lang string) *Site {
+	if lang == "" {
+		lang = h.Conf.DefaultContentLanguage()
+	}
+
+	for _, s := range h.Sites {
+		if s.Lang() == lang {
+			return s
+		}
+	}
+
+	return nil
+}
+
 // Only used in tests.
 type buildCounters struct {
 	contentRenderCounter atomic.Uint64
@@ -479,6 +497,7 @@ func (h *HugoSites) loadData() error {
 		hugofs.WalkwayConfig{
 			Fs:         h.PathSpec.BaseFs.Data.Fs,
 			IgnoreFile: h.SourceSpec.IgnoreFile,
+			PathParser: h.Conf.PathParser(),
 			WalkFn: func(path string, fi hugofs.FileMetaInfo) error {
 				if fi.IsDir() {
 					return nil
diff --git a/hugolib/hugo_sites_build.go b/hugolib/hugo_sites_build.go
index 6a9afee99..4bea93039 100644
--- a/hugolib/hugo_sites_build.go
+++ b/hugolib/hugo_sites_build.go
@@ -30,6 +30,8 @@ import (
 	"github.com/gohugoio/hugo/hugofs"
 	"github.com/gohugoio/hugo/hugofs/files"
 	"github.com/gohugoio/hugo/hugofs/glob"
+	"github.com/gohugoio/hugo/hugolib/doctree"
+	"github.com/gohugoio/hugo/hugolib/pagesfromdata"
 	"github.com/gohugoio/hugo/hugolib/segments"
 	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/output"
@@ -41,6 +43,7 @@ import (
 	"github.com/gohugoio/hugo/common/loggers"
 	"github.com/gohugoio/hugo/common/para"
 	"github.com/gohugoio/hugo/common/paths"
+	"github.com/gohugoio/hugo/common/rungroup"
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/resources/page"
 	"github.com/gohugoio/hugo/resources/page/siteidentities"
@@ -96,6 +99,10 @@ func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {
 		close(to)
 	}(errCollector, errs)
 
+	for _, s := range h.Sites {
+		s.state = siteStateInit
+	}
+
 	if h.Metrics != nil {
 		h.Metrics.Reset()
 	}
@@ -109,7 +116,7 @@ func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {
 	conf := &config
 	if conf.whatChanged == nil {
 		// Assume everything has changed
-		conf.whatChanged = &whatChanged{contentChanged: true}
+		conf.whatChanged = &whatChanged{needsPagesAssembly: true}
 	}
 
 	var prepareErr error
@@ -153,6 +160,10 @@ func (h *HugoSites) Build(config BuildCfg, events ...fsnotify.Event) error {
 		}
 	}
 
+	for _, s := range h.Sites {
+		s.state = siteStateReady
+	}
+
 	if prepareErr == nil {
 		if err := h.render(infol, conf); err != nil {
 			h.SendError(fmt.Errorf("render: %w", err))
@@ -213,7 +224,7 @@ func (h *HugoSites) initRebuild(config *BuildCfg) error {
 	})
 
 	for _, s := range h.Sites {
-		s.resetBuildState(config.whatChanged.contentChanged)
+		s.resetBuildState(config.whatChanged.needsPagesAssembly)
 	}
 
 	h.reset(config)
@@ -232,7 +243,7 @@ func (h *HugoSites) process(ctx context.Context, l logg.LevelLogger, config *Bui
 		// This is a rebuild
 		return h.processPartial(ctx, l, config, init, events)
 	}
-	return h.processFull(ctx, l, *config)
+	return h.processFull(ctx, l, config)
 }
 
 // assemble creates missing sections, applies aggregate values (e.g. dates, cascading params),
@@ -241,22 +252,24 @@ func (h *HugoSites) assemble(ctx context.Context, l logg.LevelLogger, bcfg *Buil
 	l = l.WithField("step", "assemble")
 	defer loggers.TimeTrackf(l, time.Now(), nil, "")
 
-	if !bcfg.whatChanged.contentChanged {
+	if !bcfg.whatChanged.needsPagesAssembly {
+		changes := bcfg.whatChanged.Drain()
+		if len(changes) > 0 {
+			if err := h.resolveAndClearStateForIdentities(ctx, l, nil, changes); err != nil {
+				return err
+			}
+		}
 		return nil
 	}
 
 	h.translationKeyPages.Reset()
 	assemblers := make([]*sitePagesAssembler, len(h.Sites))
 	// Changes detected during assembly (e.g. aggregate date changes)
-	assembleChanges := &whatChanged{
-		identitySet: make(map[identity.Identity]bool),
-	}
+
 	for i, s := range h.Sites {
 		assemblers[i] = &sitePagesAssembler{
 			Site:            s,
-			watching:        s.watching(),
-			incomingChanges: bcfg.whatChanged,
-			assembleChanges: assembleChanges,
+			assembleChanges: bcfg.whatChanged,
 			ctx:             ctx,
 		}
 	}
@@ -272,7 +285,7 @@ func (h *HugoSites) assemble(ctx context.Context, l logg.LevelLogger, bcfg *Buil
 		return err
 	}
 
-	changes := assembleChanges.Changes()
+	changes := bcfg.whatChanged.Drain()
 
 	// Changes from the assemble step (e.g. lastMod, cascade) needs a re-calculation
 	// of what needs to be re-built.
@@ -619,10 +632,10 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 	logger := h.Log
 
 	var (
-		tmplAdded      bool
-		tmplChanged    bool
-		i18nChanged    bool
-		contentChanged bool
+		tmplAdded          bool
+		tmplChanged        bool
+		i18nChanged        bool
+		needsPagesAssemble bool
 	)
 
 	changedPaths := struct {
@@ -696,11 +709,33 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 		switch pathInfo.Component() {
 		case files.ComponentFolderContent:
 			logger.Println("Source changed", pathInfo.Path())
-			if ids := h.pageTrees.collectAndMarkStaleIdentities(pathInfo); len(ids) > 0 {
-				changes = append(changes, ids...)
+			isContentDataFile := pathInfo.IsContentData()
+			if !isContentDataFile {
+				if ids := h.pageTrees.collectAndMarkStaleIdentities(pathInfo); len(ids) > 0 {
+					changes = append(changes, ids...)
+				}
+			} else {
+				h.pageTrees.treePagesFromTemplateAdapters.DeleteAllFunc(pathInfo.Base(),
+					func(s string, n *pagesfromdata.PagesFromTemplate) bool {
+						changes = append(changes, n.DependencyManager)
+
+						// Try to open the file to see if has been deleted.
+						f, err := n.GoTmplFi.Meta().Open()
+						if err == nil {
+							f.Close()
+						}
+						if err != nil {
+							// Remove all pages and resources below.
+							prefix := pathInfo.Base() + "/"
+							h.pageTrees.treePages.DeletePrefixAll(prefix)
+							h.pageTrees.resourceTrees.DeletePrefixAll(prefix)
+							changes = append(changes, identity.NewGlobIdentity(prefix+"*"))
+						}
+						return err != nil
+					})
 			}
 
-			contentChanged = true
+			needsPagesAssemble = true
 
 			if config.RecentlyVisited != nil {
 				// Fast render mode. Adding them to the visited queue
@@ -714,7 +749,7 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 
 			h.pageTrees.treeTaxonomyEntries.DeletePrefix("")
 
-			if delete {
+			if delete && !isContentDataFile {
 				_, ok := h.pageTrees.treePages.LongestPrefixAll(pathInfo.Base())
 				if ok {
 					h.pageTrees.treePages.DeleteAll(pathInfo.Base())
@@ -853,8 +888,8 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 	resourceFiles := h.fileEventsContentPaths(addedOrChangedContent)
 
 	changed := &whatChanged{
-		contentChanged: contentChanged,
-		identitySet:    make(identity.Identities),
+		needsPagesAssembly: needsPagesAssemble,
+		identitySet:        make(identity.Identities),
 	}
 	changed.Add(changes...)
 
@@ -876,10 +911,7 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 		}
 	}
 
-	// Removes duplicates.
-	changes = changed.identitySet.AsSlice()
-
-	if err := h.resolveAndClearStateForIdentities(ctx, l, cacheBusterOr, changes); err != nil {
+	if err := h.resolveAndClearStateForIdentities(ctx, l, cacheBusterOr, changed.Drain()); err != nil {
 		return err
 	}
 
@@ -907,7 +939,13 @@ func (h *HugoSites) processPartial(ctx context.Context, l logg.LevelLogger, conf
 	}
 
 	if resourceFiles != nil {
-		if err := h.processFiles(ctx, l, *config, resourceFiles...); err != nil {
+		if err := h.processFiles(ctx, l, config, resourceFiles...); err != nil {
+			return err
+		}
+	}
+
+	if h.isRebuild() {
+		if err := h.processContentAdaptersOnRebuild(ctx, config); err != nil {
 			return err
 		}
 	}
@@ -926,7 +964,7 @@ func (h *HugoSites) LogServerAddresses() {
 	}
 }
 
-func (h *HugoSites) processFull(ctx context.Context, l logg.LevelLogger, config BuildCfg) (err error) {
+func (h *HugoSites) processFull(ctx context.Context, l logg.LevelLogger, config *BuildCfg) (err error) {
 	if err = h.processFiles(ctx, l, config); err != nil {
 		err = fmt.Errorf("readAndProcessContent: %w", err)
 		return
@@ -934,7 +972,49 @@ func (h *HugoSites) processFull(ctx context.Context, l logg.LevelLogger, config
 	return err
 }
 
-func (s *HugoSites) processFiles(ctx context.Context, l logg.LevelLogger, buildConfig BuildCfg, filenames ...pathChange) error {
+func (s *Site) handleContentAdapterChanges(bi pagesfromdata.BuildInfo, buildConfig *BuildCfg) {
+	if !s.h.isRebuild() {
+		return
+	}
+
+	if len(bi.ChangedIdentities) > 0 {
+		buildConfig.whatChanged.Add(bi.ChangedIdentities...)
+		buildConfig.whatChanged.needsPagesAssembly = true
+	}
+
+	for _, p := range bi.DeletedPaths {
+		pp := path.Join(bi.Path.Base(), p)
+		if v, ok := s.pageMap.treePages.Delete(pp); ok {
+			buildConfig.whatChanged.Add(v.GetIdentity())
+		}
+	}
+}
+
+func (h *HugoSites) processContentAdaptersOnRebuild(ctx context.Context, buildConfig *BuildCfg) error {
+	g := rungroup.Run[*pagesfromdata.PagesFromTemplate](ctx, rungroup.Config[*pagesfromdata.PagesFromTemplate]{
+		NumWorkers: h.numWorkers,
+		Handle: func(ctx context.Context, p *pagesfromdata.PagesFromTemplate) error {
+			bi, err := p.Execute(ctx)
+			if err != nil {
+				return err
+			}
+			s := p.Site.(*Site)
+			s.handleContentAdapterChanges(bi, buildConfig)
+			return nil
+		},
+	})
+
+	h.pageTrees.treePagesFromTemplateAdapters.WalkPrefixRaw(doctree.LockTypeRead, "", func(key string, p *pagesfromdata.PagesFromTemplate) (bool, error) {
+		if p.StaleVersion() > 0 {
+			g.Enqueue(p)
+		}
+		return false, nil
+	})
+
+	return g.Wait()
+}
+
+func (s *HugoSites) processFiles(ctx context.Context, l logg.LevelLogger, buildConfig *BuildCfg, filenames ...pathChange) error {
 	if s.Deps == nil {
 		panic("nil deps on site")
 	}
@@ -944,7 +1024,7 @@ func (s *HugoSites) processFiles(ctx context.Context, l logg.LevelLogger, buildC
 	// For inserts, we can pick an arbitrary pageMap.
 	pageMap := s.Sites[0].pageMap
 
-	c := newPagesCollector(ctx, s.h, sourceSpec, s.Log, l, pageMap, filenames)
+	c := newPagesCollector(ctx, s.h, sourceSpec, s.Log, l, pageMap, buildConfig, filenames)
 
 	if err := c.Collect(); err != nil {
 		return err
diff --git a/hugolib/hugo_smoke_test.go b/hugolib/hugo_smoke_test.go
index 42b0ab488..a4a5b7cbd 100644
--- a/hugolib/hugo_smoke_test.go
+++ b/hugolib/hugo_smoke_test.go
@@ -41,7 +41,7 @@ Home: {{ .Title }}
 		IntegrationTestConfig{
 			T:           t,
 			TxtarString: files,
-			LogLevel:    logg.LevelTrace,
+			// LogLevel:    logg.LevelTrace,
 		},
 	).Build()
 
diff --git a/hugolib/page.go b/hugolib/page.go
index 028d3fa95..20751c57c 100644
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -510,9 +510,15 @@ func (p *pageState) renderResources() error {
 				continue
 			}
 
+			if _, isWrapper := r.(resource.ResourceWrapper); isWrapper {
+				// Skip resources that are wrapped.
+				// These gets published on its own.
+				continue
+			}
+
 			src, ok := r.(resource.Source)
 			if !ok {
-				initErr = fmt.Errorf("resource %T does not support resource.Source", src)
+				initErr = fmt.Errorf("resource %T does not support resource.Source", r)
 				return
 			}
 
@@ -581,7 +587,11 @@ func (p *pageState) getPageInfoForError() string {
 func (p *pageState) getContentConverter() converter.Converter {
 	var err error
 	p.contentConverterInit.Do(func() {
-		markup := p.m.pageConfig.Markup
+		if p.m.pageConfig.ContentMediaType.IsZero() {
+			panic("ContentMediaType not set")
+		}
+		markup := p.m.pageConfig.ContentMediaType.SubType
+
 		if markup == "html" {
 			// Only used for shortcode inner content.
 			markup = "markdown"
diff --git a/hugolib/page__content.go b/hugolib/page__content.go
index 99ed824cd..1ef31f0f9 100644
--- a/hugolib/page__content.go
+++ b/hugolib/page__content.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"html/template"
 	"io"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -54,21 +55,31 @@ type pageContentReplacement struct {
 	source pageparser.Item
 }
 
-func (m *pageMeta) parseFrontMatter(h *HugoSites, pid uint64, sourceKey string) (*contentParseInfo, error) {
-	var openSource hugio.OpenReadSeekCloser
-	if m.f != nil {
-		meta := m.f.FileInfo().Meta()
-		openSource = func() (hugio.ReadSeekCloser, error) {
-			r, err := meta.Open()
-			if err != nil {
-				return nil, fmt.Errorf("failed to open file %q: %w", meta.Filename, err)
+func (m *pageMeta) parseFrontMatter(h *HugoSites, pid uint64) (*contentParseInfo, error) {
+	var (
+		sourceKey  string
+		openSource hugio.OpenReadSeekCloser
+		hasContent = m.pageConfig.IsFromContentAdapter
+	)
+
+	if m.f != nil && !hasContent {
+		sourceKey = filepath.ToSlash(m.f.Filename())
+		if !hasContent {
+			meta := m.f.FileInfo().Meta()
+			openSource = func() (hugio.ReadSeekCloser, error) {
+				r, err := meta.Open()
+				if err != nil {
+					return nil, fmt.Errorf("failed to open file %q: %w", meta.Filename, err)
+				}
+				return r, nil
 			}
-			return r, nil
 		}
+	} else if hasContent {
+		openSource = m.pageConfig.Content.ValueAsOpenReadSeekCloser()
 	}
 
 	if sourceKey == "" {
-		sourceKey = strconv.Itoa(int(pid))
+		sourceKey = strconv.FormatUint(pid, 10)
 	}
 
 	pi := &contentParseInfo{
@@ -93,6 +104,11 @@ func (m *pageMeta) parseFrontMatter(h *HugoSites, pid uint64, sourceKey string)
 
 	pi.itemsStep1 = items
 
+	if hasContent {
+		// No front matter.
+		return pi, nil
+	}
+
 	if err := pi.mapFrontMatter(source); err != nil {
 		return nil, err
 	}
@@ -567,15 +583,14 @@ func (c *cachedContent) contentRendered(ctx context.Context, cp *pageContentOutp
 		var result contentSummary // hasVariants bool
 
 		if c.pi.hasSummaryDivider {
-			isHTML := cp.po.p.m.pageConfig.Markup == "html"
-			if isHTML {
+			if cp.po.p.m.pageConfig.ContentMediaType.IsHTML() {
 				// Use the summary sections as provided by the user.
 				i := bytes.Index(b, internalSummaryDividerPre)
 				result.summary = helpers.BytesToHTML(b[:i])
 				b = b[i+len(internalSummaryDividerPre):]
 
 			} else {
-				summary, content, err := splitUserDefinedSummaryAndContent(cp.po.p.m.pageConfig.Markup, b)
+				summary, content, err := splitUserDefinedSummaryAndContent(cp.po.p.m.pageConfig.Content.Markup, b)
 				if err != nil {
 					cp.po.p.s.Log.Errorf("Failed to set user defined summary for page %q: %s", cp.po.p.pathOrTitle(), err)
 				} else {
@@ -665,7 +680,7 @@ func (c *cachedContent) contentToC(ctx context.Context, cp *pageContentOutput) (
 			p.pageOutputTemplateVariationsState.Add(1)
 		}
 
-		isHTML := cp.po.p.m.pageConfig.Markup == "html"
+		isHTML := cp.po.p.m.pageConfig.ContentMediaType.IsHTML()
 
 		if !isHTML {
 			createAndSetToC := func(tocProvider converter.TableOfContentsProvider) {
@@ -788,7 +803,7 @@ func (c *cachedContent) contentPlain(ctx context.Context, cp *pageContentOutput)
 			if err != nil {
 				return nil, err
 			}
-			html := cp.po.p.s.ContentSpec.TrimShortHTML(b.Bytes(), cp.po.p.m.pageConfig.Markup)
+			html := cp.po.p.s.ContentSpec.TrimShortHTML(b.Bytes(), cp.po.p.m.pageConfig.Content.Markup)
 			result.summary = helpers.BytesToHTML(html)
 		} else {
 			var summary string
diff --git a/hugolib/page__meta.go b/hugolib/page__meta.go
index a88fe528d..fbc1a8aa1 100644
--- a/hugolib/page__meta.go
+++ b/hugolib/page__meta.go
@@ -54,7 +54,7 @@ type pageMeta struct {
 	singular string // Set for kind == KindTerm and kind == KindTaxonomy.
 
 	resource.Staler
-	pageMetaParams
+	*pageMetaParams
 	pageMetaFrontMatter
 
 	// Set for standalone pages, e.g. robotsTXT.
@@ -100,7 +100,7 @@ type pageMetaFrontMatter struct {
 func (m *pageMetaParams) init(preserveOringal bool) {
 	if preserveOringal {
 		m.paramsOriginal = xmaps.Clone[maps.Params](m.pageConfig.Params)
-		m.cascadeOriginal = xmaps.Clone[map[page.PageMatcher]maps.Params](m.pageConfig.Cascade)
+		m.cascadeOriginal = xmaps.Clone[map[page.PageMatcher]maps.Params](m.pageConfig.CascadeCompiled)
 	}
 }
 
@@ -137,19 +137,19 @@ func (p *pageMeta) BundleType() string {
 }
 
 func (p *pageMeta) Date() time.Time {
-	return p.pageConfig.Date
+	return p.pageConfig.Dates.Date
 }
 
 func (p *pageMeta) PublishDate() time.Time {
-	return p.pageConfig.PublishDate
+	return p.pageConfig.Dates.PublishDate
 }
 
 func (p *pageMeta) Lastmod() time.Time {
-	return p.pageConfig.Lastmod
+	return p.pageConfig.Dates.Lastmod
 }
 
 func (p *pageMeta) ExpiryDate() time.Time {
-	return p.pageConfig.ExpiryDate
+	return p.pageConfig.Dates.ExpiryDate
 }
 
 func (p *pageMeta) Description() string {
@@ -280,9 +280,6 @@ func (p *pageMeta) setMetaPre(pi *contentParseInfo, logger loggers.Logger, conf
 
 	if frontmatter != nil {
 		pcfg := p.pageConfig
-		if pcfg == nil {
-			panic("pageConfig not set")
-		}
 		// Needed for case insensitive fetching of params values
 		maps.PrepareParams(frontmatter)
 		pcfg.Params = frontmatter
@@ -293,7 +290,7 @@ func (p *pageMeta) setMetaPre(pi *contentParseInfo, logger loggers.Logger, conf
 			if err != nil {
 				return err
 			}
-			pcfg.Cascade = cascade
+			pcfg.CascadeCompiled = cascade
 		}
 
 		// Look for path, lang and kind, all of which values we need early on.
@@ -331,18 +328,18 @@ func (ps *pageState) setMetaPost(cascade map[page.PageMatcher]maps.Params) error
 	ps.m.setMetaPostCount++
 	var cascadeHashPre uint64
 	if ps.m.setMetaPostCount > 1 {
-		cascadeHashPre = identity.HashUint64(ps.m.pageConfig.Cascade)
-		ps.m.pageConfig.Cascade = xmaps.Clone[map[page.PageMatcher]maps.Params](ps.m.cascadeOriginal)
+		cascadeHashPre = identity.HashUint64(ps.m.pageConfig.CascadeCompiled)
+		ps.m.pageConfig.CascadeCompiled = xmaps.Clone[map[page.PageMatcher]maps.Params](ps.m.cascadeOriginal)
 
 	}
 
 	// Apply cascades first so they can be overridden later.
 	if cascade != nil {
-		if ps.m.pageConfig.Cascade != nil {
+		if ps.m.pageConfig.CascadeCompiled != nil {
 			for k, v := range cascade {
-				vv, found := ps.m.pageConfig.Cascade[k]
+				vv, found := ps.m.pageConfig.CascadeCompiled[k]
 				if !found {
-					ps.m.pageConfig.Cascade[k] = v
+					ps.m.pageConfig.CascadeCompiled[k] = v
 				} else {
 					// Merge
 					for ck, cv := range v {
@@ -352,18 +349,18 @@ func (ps *pageState) setMetaPost(cascade map[page.PageMatcher]maps.Params) error
 					}
 				}
 			}
-			cascade = ps.m.pageConfig.Cascade
+			cascade = ps.m.pageConfig.CascadeCompiled
 		} else {
-			ps.m.pageConfig.Cascade = cascade
+			ps.m.pageConfig.CascadeCompiled = cascade
 		}
 	}
 
 	if cascade == nil {
-		cascade = ps.m.pageConfig.Cascade
+		cascade = ps.m.pageConfig.CascadeCompiled
 	}
 
 	if ps.m.setMetaPostCount > 1 {
-		ps.m.setMetaPostCascadeChanged = cascadeHashPre != identity.HashUint64(ps.m.pageConfig.Cascade)
+		ps.m.setMetaPostCascadeChanged = cascadeHashPre != identity.HashUint64(ps.m.pageConfig.CascadeCompiled)
 		if !ps.m.setMetaPostCascadeChanged {
 
 			// No changes, restore any value that may be changed by aggregation.
@@ -404,11 +401,17 @@ func (p *pageState) setMetaPostParams() error {
 	pm := p.m
 	var mtime time.Time
 	var contentBaseName string
+	var ext string
+	var isContentAdapter bool
 	if p.File() != nil {
+		isContentAdapter = p.File().IsContentAdapter()
 		contentBaseName = p.File().ContentBaseName()
 		if p.File().FileInfo() != nil {
 			mtime = p.File().FileInfo().ModTime()
 		}
+		if !isContentAdapter {
+			ext = p.File().Ext()
+		}
 	}
 
 	var gitAuthorDate time.Time
@@ -432,6 +435,11 @@ func (p *pageState) setMetaPostParams() error {
 		p.s.Log.Errorf("Failed to handle dates for page %q: %s", p.pathOrTitle(), err)
 	}
 
+	if isContentAdapter {
+		// Done.
+		return nil
+	}
+
 	var buildConfig any
 	var isNewBuildKeyword bool
 	if v, ok := pm.pageConfig.Params["_build"]; ok {
@@ -460,8 +468,10 @@ params:
 	var sitemapSet bool
 
 	pcfg := pm.pageConfig
-
 	params := pcfg.Params
+	if params == nil {
+		panic("params not set for " + p.Title())
+	}
 
 	var draft, published, isCJKLanguage *bool
 	var userParams map[string]any
@@ -554,8 +564,8 @@ params:
 			pcfg.Layout = cast.ToString(v)
 			params[loki] = pcfg.Layout
 		case "markup":
-			pcfg.Markup = cast.ToString(v)
-			params[loki] = pcfg.Markup
+			pcfg.Content.Markup = cast.ToString(v)
+			params[loki] = pcfg.Content.Markup
 		case "weight":
 			pcfg.Weight = cast.ToInt(v)
 			params[loki] = pcfg.Weight
@@ -605,7 +615,7 @@ params:
 			}
 
 			if handled {
-				pcfg.Resources = resources
+				pcfg.ResourcesMeta = resources
 				break
 			}
 			fallthrough
@@ -652,8 +662,6 @@ params:
 		pcfg.Sitemap = p.s.conf.Sitemap
 	}
 
-	pcfg.Markup = p.s.ContentSpec.ResolveMarkup(pcfg.Markup)
-
 	if draft != nil && published != nil {
 		pcfg.Draft = *draft
 		p.m.s.Log.Warnf("page %q has both draft and published settings in its frontmatter. Using draft.", p.File().Filename())
@@ -676,6 +684,14 @@ params:
 
 	params["iscjklanguage"] = pcfg.IsCJKLanguage
 
+	if err := pcfg.Validate(false); err != nil {
+		return err
+	}
+
+	if err := pcfg.Compile("", false, ext, p.s.Log, p.s.conf.MediaTypes.Config); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -731,18 +747,16 @@ func (p *pageMeta) applyDefaultValues() error {
 		(&p.pageConfig.Build).Disable()
 	}
 
-	if p.pageConfig.Markup == "" {
+	if p.pageConfig.Content.Markup == "" {
 		if p.File() != nil {
 			// Fall back to file extension
-			p.pageConfig.Markup = p.s.ContentSpec.ResolveMarkup(p.File().Ext())
+			p.pageConfig.Content.Markup = p.s.ContentSpec.ResolveMarkup(p.File().Ext())
 		}
-		if p.pageConfig.Markup == "" {
-			p.pageConfig.Markup = "markdown"
+		if p.pageConfig.Content.Markup == "" {
+			p.pageConfig.Content.Markup = "markdown"
 		}
 	}
 
-	p.pageConfig.IsGoldmark = p.s.ContentSpec.Converters.IsGoldmark(p.pageConfig.Markup)
-
 	if p.pageConfig.Title == "" && p.f == nil {
 		switch p.Kind() {
 		case kinds.KindHome:
diff --git a/hugolib/page__new.go b/hugolib/page__new.go
index ac3962883..04c68ba6a 100644
--- a/hugolib/page__new.go
+++ b/hugolib/page__new.go
@@ -15,7 +15,6 @@ package hugolib
 
 import (
 	"fmt"
-	"path/filepath"
 	"sync"
 	"sync/atomic"
 
@@ -36,21 +35,17 @@ var pageIDCounter atomic.Uint64
 
 func (h *HugoSites) newPage(m *pageMeta) (*pageState, *paths.Path, error) {
 	m.Staler = &resources.AtomicStaler{}
-	if m.pageConfig == nil {
-		m.pageMetaParams = pageMetaParams{
-			pageConfig: &pagemeta.PageConfig{
-				Params: maps.Params{},
-			},
+	if m.pageMetaParams == nil {
+		m.pageMetaParams = &pageMetaParams{
+			pageConfig: &pagemeta.PageConfig{},
 		}
 	}
-
-	var sourceKey string
-	if m.f != nil {
-		sourceKey = filepath.ToSlash(m.f.Filename())
+	if m.pageConfig.Params == nil {
+		m.pageConfig.Params = maps.Params{}
 	}
 
 	pid := pageIDCounter.Add(1)
-	pi, err := m.parseFrontMatter(h, pid, sourceKey)
+	pi, err := m.parseFrontMatter(h, pid)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -69,28 +64,40 @@ func (h *HugoSites) newPage(m *pageMeta) (*pageState, *paths.Path, error) {
 		s := m.pageConfig.Path
 		if !paths.HasExt(s) {
 			var (
-				isBranch bool
-				ext      string = "md"
+				isBranch    bool
+				isBranchSet bool
+				ext         string = m.pageConfig.ContentMediaType.FirstSuffix.Suffix
 			)
 			if pcfg.Kind != "" {
 				isBranch = kinds.IsBranch(pcfg.Kind)
-			} else if m.pathInfo != nil {
-				isBranch = m.pathInfo.IsBranchBundle()
-				if m.pathInfo.Ext() != "" {
-					ext = m.pathInfo.Ext()
-				}
-			} else if m.f != nil {
-				pi := m.f.FileInfo().Meta().PathInfo
-				isBranch = pi.IsBranchBundle()
-				if pi.Ext() != "" {
-					ext = pi.Ext()
+				isBranchSet = true
+			}
+
+			if !pcfg.IsFromContentAdapter {
+				if m.pathInfo != nil {
+					if !isBranchSet {
+						isBranch = m.pathInfo.IsBranchBundle()
+					}
+					if m.pathInfo.Ext() != "" {
+						ext = m.pathInfo.Ext()
+					}
+				} else if m.f != nil {
+					pi := m.f.FileInfo().Meta().PathInfo
+					if !isBranchSet {
+						isBranch = pi.IsBranchBundle()
+					}
+					if pi.Ext() != "" {
+						ext = pi.Ext()
+					}
 				}
 			}
+
 			if isBranch {
 				s += "/_index." + ext
 			} else {
 				s += "/index." + ext
 			}
+
 		}
 		m.pathInfo = h.Conf.PathParser().Parse(files.ComponentFolderContent, s)
 	} else if m.pathInfo == nil {
@@ -112,23 +119,13 @@ func (h *HugoSites) newPage(m *pageMeta) (*pageState, *paths.Path, error) {
 			} else if m.f != nil {
 				meta := m.f.FileInfo().Meta()
 				lang = meta.Lang
-				m.s = h.Sites[meta.LangIndex]
 			} else {
 				lang = m.pathInfo.Lang()
 			}
-			if lang == "" {
-				lang = h.Conf.DefaultContentLanguage()
-			}
-			var found bool
-			for _, ss := range h.Sites {
-				if ss.Lang() == lang {
-					m.s = ss
-					found = true
-					break
-				}
-			}
 
-			if !found {
+			m.s = h.resolveSite(lang)
+
+			if m.s == nil {
 				return nil, fmt.Errorf("no site found for language %q", lang)
 			}
 		}
diff --git a/hugolib/page__per_output.go b/hugolib/page__per_output.go
index 6b4b8f55e..5b039b91b 100644
--- a/hugolib/page__per_output.go
+++ b/hugolib/page__per_output.go
@@ -25,6 +25,8 @@ import (
 	"github.com/gohugoio/hugo/common/text"
 	"github.com/gohugoio/hugo/common/types/hstring"
 	"github.com/gohugoio/hugo/identity"
+	"github.com/gohugoio/hugo/markup"
+	"github.com/gohugoio/hugo/media"
 	"github.com/gohugoio/hugo/parser/pageparser"
 	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/cast"
@@ -262,6 +264,9 @@ func (pco *pageContentOutput) RenderString(ctx context.Context, args ...any) (te
 		if err := mapstructure.WeakDecode(m, &opts); err != nil {
 			return "", fmt.Errorf("failed to decode options: %w", err)
 		}
+		if opts.Markup != "" {
+			opts.Markup = markup.ResolveMarkup(opts.Markup)
+		}
 	}
 
 	contentToRenderv := args[sidx]
@@ -283,7 +288,8 @@ func (pco *pageContentOutput) RenderString(ctx context.Context, args ...any) (te
 	}
 
 	conv := pco.po.p.getContentConverter()
-	if opts.Markup != "" && opts.Markup != pco.po.p.m.pageConfig.Markup {
+
+	if opts.Markup != "" && opts.Markup != pco.po.p.m.pageConfig.ContentMediaType.SubType {
 		var err error
 		conv, err = pco.po.p.m.newContentConverter(pco.po.p, opts.Markup)
 		if err != nil {
@@ -376,7 +382,7 @@ func (pco *pageContentOutput) RenderString(ctx context.Context, args ...any) (te
 	}
 
 	if opts.Display == "inline" {
-		markup := pco.po.p.m.pageConfig.Markup
+		markup := pco.po.p.m.pageConfig.Content.Markup
 		if opts.Markup != "" {
 			markup = pco.po.p.s.ContentSpec.ResolveMarkup(opts.Markup)
 		}
@@ -657,7 +663,7 @@ func splitUserDefinedSummaryAndContent(markup string, c []byte) (summary []byte,
 
 	startTag := "p"
 	switch markup {
-	case "asciidocext":
+	case media.DefaultContentTypes.AsciiDoc.SubType:
 		startTag = "div"
 	}
 
diff --git a/hugolib/pages_capture.go b/hugolib/pages_capture.go
index 1633feb3e..96c2c0f96 100644
--- a/hugolib/pages_capture.go
+++ b/hugolib/pages_capture.go
@@ -42,18 +42,20 @@ func newPagesCollector(
 	logger loggers.Logger,
 	infoLogger logg.LevelLogger,
 	m *pageMap,
+	buildConfig *BuildCfg,
 	ids []pathChange,
 ) *pagesCollector {
 	return &pagesCollector{
-		ctx:        ctx,
-		h:          h,
-		fs:         sp.BaseFs.Content.Fs,
-		m:          m,
-		sp:         sp,
-		logger:     logger,
-		infoLogger: infoLogger,
-		ids:        ids,
-		seenDirs:   make(map[string]bool),
+		ctx:         ctx,
+		h:           h,
+		fs:          sp.BaseFs.Content.Fs,
+		m:           m,
+		sp:          sp,
+		logger:      logger,
+		infoLogger:  infoLogger,
+		buildConfig: buildConfig,
+		ids:         ids,
+		seenDirs:    make(map[string]bool),
 	}
 }
 
@@ -68,6 +70,8 @@ type pagesCollector struct {
 
 	fs afero.Fs
 
+	buildConfig *BuildCfg
+
 	// List of paths that have changed. Used in partial builds.
 	ids      []pathChange
 	seenDirs map[string]bool
@@ -82,6 +86,8 @@ func (c *pagesCollector) Collect() (collectErr error) {
 	var (
 		numWorkers             = c.h.numWorkers
 		numFilesProcessedTotal atomic.Uint64
+		numPagesProcessedTotal atomic.Uint64
+		numResourcesProcessed  atomic.Uint64
 		numFilesProcessedLast  uint64
 		fileBatchTimer         = time.Now()
 		fileBatchTimerMu       sync.Mutex
@@ -98,6 +104,8 @@ func (c *pagesCollector) Collect() (collectErr error) {
 				logg.Fields{
 					logg.Field{Name: "files", Value: numFilesProcessedBatch},
 					logg.Field{Name: "files_total", Value: numFilesProcessedTotal.Load()},
+					logg.Field{Name: "pages_total", Value: numPagesProcessedTotal.Load()},
+					logg.Field{Name: "resources_total", Value: numResourcesProcessed.Load()},
 				},
 				"",
 			)
@@ -113,10 +121,13 @@ func (c *pagesCollector) Collect() (collectErr error) {
 	c.g = rungroup.Run[hugofs.FileMetaInfo](c.ctx, rungroup.Config[hugofs.FileMetaInfo]{
 		NumWorkers: numWorkers,
 		Handle: func(ctx context.Context, fi hugofs.FileMetaInfo) error {
-			if err := c.m.AddFi(fi); err != nil {
+			numPages, numResources, err := c.m.AddFi(fi, c.buildConfig)
+			if err != nil {
 				return hugofs.AddFileInfoToError(err, fi, c.fs)
 			}
 			numFilesProcessedTotal.Add(1)
+			numPagesProcessedTotal.Add(numPages)
+			numResourcesProcessed.Add(numResources)
 			if numFilesProcessedTotal.Load()%1000 == 0 {
 				logFilesProcessed(false)
 			}
@@ -243,6 +254,21 @@ func (c *pagesCollector) collectDirDir(path string, root hugofs.FileMetaInfo, in
 			return nil, nil
 		}
 
+		n := 0
+		for _, fi := range readdir {
+			if fi.Meta().PathInfo.IsContentData() {
+				// _content.json
+				// These are not part of any bundle, so just add them directly and remove them from the readdir slice.
+				if err := c.g.Enqueue(fi); err != nil {
+					return nil, err
+				}
+			} else {
+				readdir[n] = fi
+				n++
+			}
+		}
+		readdir = readdir[:n]
+
 		// Pick the first regular file.
 		var first hugofs.FileMetaInfo
 		for _, fi := range readdir {
@@ -260,6 +286,7 @@ func (c *pagesCollector) collectDirDir(path string, root hugofs.FileMetaInfo, in
 
 		// Any bundle file will always be first.
 		firstPi := first.Meta().PathInfo
+
 		if firstPi == nil {
 			panic(fmt.Sprintf("collectDirDir: no path info for %q", first.Meta().Filename))
 		}
@@ -320,6 +347,7 @@ func (c *pagesCollector) collectDirDir(path string, root hugofs.FileMetaInfo, in
 			Info:       root,
 			Fs:         c.fs,
 			IgnoreFile: c.h.SourceSpec.IgnoreFile,
+			PathParser: c.h.Conf.PathParser(),
 			HookPre:    preHook,
 			HookPost:   postHook,
 			WalkFn:     wfn,
@@ -370,6 +398,7 @@ func (c *pagesCollector) handleBundleLeaf(dir, bundle hugofs.FileMetaInfo, inPat
 			Info:       dir,
 			DirEntries: readdir,
 			IgnoreFile: c.h.SourceSpec.IgnoreFile,
+			PathParser: c.h.Conf.PathParser(),
 			WalkFn:     walk,
 		})
 
diff --git a/hugolib/pagesfromdata/pagesfromgotmpl.go b/hugolib/pagesfromdata/pagesfromgotmpl.go
new file mode 100644
index 000000000..4107f9e33
--- /dev/null
+++ b/hugolib/pagesfromdata/pagesfromgotmpl.go
@@ -0,0 +1,331 @@
+// Copyright 2024 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pagesfromdata
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"path/filepath"
+
+	"github.com/gohugoio/hugo/common/maps"
+	"github.com/gohugoio/hugo/common/paths"
+	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/hugofs"
+	"github.com/gohugoio/hugo/identity"
+	"github.com/gohugoio/hugo/resources/page"
+	"github.com/gohugoio/hugo/resources/page/pagemeta"
+	"github.com/gohugoio/hugo/resources/resource"
+	"github.com/gohugoio/hugo/tpl"
+	"github.com/mitchellh/mapstructure"
+	"github.com/spf13/cast"
+)
+
+type PagesFromDataTemplateContext interface {
+	// AddPage adds a new page to the site.
+	// The first return value will always be an empty string.
+	AddPage(any) (string, error)
+
+	// AddResource adds a new resource to the site.
+	// The first return value will always be an empty string.
+	AddResource(any) (string, error)
+
+	// The site to which the pages will be added.
+	Site() page.Site
+
+	// The same template may be executed multiple times for multiple languages.
+	// The Store can be used to store state between these invocations.
+	Store() *maps.Scratch
+
+	// By default, the template will be executed for the language
+	// defined by the _content.gotmpl file (e.g. its mount definition).
+	// This method can be used to activate the template for all languages.
+	// The return value will always be an empty string.
+	EnableAllLanguages() string
+}
+
+var _ PagesFromDataTemplateContext = (*pagesFromDataTemplateContext)(nil)
+
+type pagesFromDataTemplateContext struct {
+	p *PagesFromTemplate
+}
+
+func (p *pagesFromDataTemplateContext) toPathMap(v any) (string, map[string]any, error) {
+	m, err := maps.ToStringMapE(v)
+	if err != nil {
+		return "", nil, err
+	}
+	pathv, ok := m["path"]
+	if !ok {
+		return "", nil, fmt.Errorf("path not set")
+	}
+	path, err := cast.ToStringE(pathv)
+	if err != nil || path == "" {
+		return "", nil, fmt.Errorf("invalid path %q", path)
+	}
+	return path, m, nil
+}
+
+func (p *pagesFromDataTemplateContext) AddPage(v any) (string, error) {
+	path, m, err := p.toPathMap(v)
+	if err != nil {
+		return "", err
+	}
+
+	if !p.p.buildState.checkHasChangedAndSetSourceInfo(path, m) {
+		return "", nil
+	}
+
+	pd := pagemeta.DefaultPageConfig
+	pd.IsFromContentAdapter = true
+
+	if err := mapstructure.WeakDecode(m, &pd); err != nil {
+		return "", fmt.Errorf("failed to decode page map: %w", err)
+	}
+
+	p.p.buildState.NumPagesAdded++
+
+	if err := pd.Validate(true); err != nil {
+		return "", err
+	}
+
+	return "", p.p.HandlePage(p.p, &pd)
+}
+
+func (p *pagesFromDataTemplateContext) AddResource(v any) (string, error) {
+	path, m, err := p.toPathMap(v)
+	if err != nil {
+		return "", err
+	}
+
+	if !p.p.buildState.checkHasChangedAndSetSourceInfo(path, m) {
+		return "", nil
+	}
+
+	var rd pagemeta.ResourceConfig
+	if err := mapstructure.WeakDecode(m, &rd); err != nil {
+		return "", err
+	}
+
+	p.p.buildState.NumResourcesAdded++
+
+	if err := rd.Validate(); err != nil {
+		return "", err
+	}
+
+	return "", p.p.HandleResource(p.p, &rd)
+}
+
+func (p *pagesFromDataTemplateContext) Site() page.Site {
+	return p.p.Site
+}
+
+func (p *pagesFromDataTemplateContext) Store() *maps.Scratch {
+	return p.p.store
+}
+
+func (p *pagesFromDataTemplateContext) EnableAllLanguages() string {
+	p.p.buildState.EnableAllLanguages = true
+	return ""
+}
+
+func NewPagesFromTemplate(opts PagesFromTemplateOptions) *PagesFromTemplate {
+	return &PagesFromTemplate{
+		PagesFromTemplateOptions: opts,
+		PagesFromTemplateDeps:    opts.DepsFromSite(opts.Site),
+		buildState: &BuildState{
+			sourceInfosCurrent: maps.NewCache[string, *sourceInfo](),
+		},
+		store: maps.NewScratch(),
+	}
+}
+
+type PagesFromTemplateOptions struct {
+	Site         page.Site
+	DepsFromSite func(page.Site) PagesFromTemplateDeps
+
+	DependencyManager identity.Manager
+
+	Watching bool
+
+	HandlePage     func(pt *PagesFromTemplate, p *pagemeta.PageConfig) error
+	HandleResource func(pt *PagesFromTemplate, p *pagemeta.ResourceConfig) error
+
+	GoTmplFi hugofs.FileMetaInfo
+}
+
+type PagesFromTemplateDeps struct {
+	TmplFinder tpl.TemplateParseFinder
+	TmplExec   tpl.TemplateExecutor
+}
+
+var _ resource.Staler = (*PagesFromTemplate)(nil)
+
+type PagesFromTemplate struct {
+	PagesFromTemplateOptions
+	PagesFromTemplateDeps
+	buildState *BuildState
+	store      *maps.Scratch
+}
+
+func (b *PagesFromTemplate) AddChange(id identity.Identity) {
+	b.buildState.ChangedIdentities = append(b.buildState.ChangedIdentities, id)
+}
+
+func (b *PagesFromTemplate) MarkStale() {
+	b.buildState.StaleVersion++
+}
+
+func (b *PagesFromTemplate) StaleVersion() uint32 {
+	return b.buildState.StaleVersion
+}
+
+type BuildInfo struct {
+	NumPagesAdded      uint64
+	NumResourcesAdded  uint64
+	EnableAllLanguages bool
+	ChangedIdentities  []identity.Identity
+	DeletedPaths       []string
+	Path               *paths.Path
+}
+
+type BuildState struct {
+	StaleVersion uint32
+
+	EnableAllLanguages bool
+
+	// Paths deleted in the current build.
+	DeletedPaths []string
+
+	// Changed identities in the current build.
+	ChangedIdentities []identity.Identity
+
+	NumPagesAdded     uint64
+	NumResourcesAdded uint64
+
+	sourceInfosCurrent  *maps.Cache[string, *sourceInfo]
+	sourceInfosPrevious *maps.Cache[string, *sourceInfo]
+}
+
+func (b *BuildState) hash(v any) uint64 {
+	return identity.HashUint64(v)
+}
+
+func (b *BuildState) checkHasChangedAndSetSourceInfo(changedPath string, v any) bool {
+	h := b.hash(v)
+	si, found := b.sourceInfosPrevious.Get(changedPath)
+	if found {
+		b.sourceInfosCurrent.Set(changedPath, si)
+		if si.hash == h {
+			return false
+		}
+	} else {
+		si = &sourceInfo{}
+		b.sourceInfosCurrent.Set(changedPath, si)
+	}
+	si.hash = h
+	return true
+}
+
+func (b *BuildState) resolveDeletedPaths() {
+	if b.sourceInfosPrevious == nil {
+		b.DeletedPaths = nil
+		return
+	}
+	var paths []string
+	b.sourceInfosPrevious.ForEeach(func(k string, _ *sourceInfo) {
+		if _, found := b.sourceInfosCurrent.Get(k); !found {
+			paths = append(paths, k)
+		}
+	})
+
+	b.DeletedPaths = paths
+}
+
+func (b *BuildState) PrepareNextBuild() {
+	b.sourceInfosPrevious = b.sourceInfosCurrent
+	b.sourceInfosCurrent = maps.NewCache[string, *sourceInfo]()
+	b.StaleVersion = 0
+	b.DeletedPaths = nil
+	b.ChangedIdentities = nil
+	b.NumPagesAdded = 0
+	b.NumResourcesAdded = 0
+}
+
+type sourceInfo struct {
+	hash uint64
+}
+
+func (p PagesFromTemplate) CloneForSite(s page.Site) *PagesFromTemplate {
+	// We deliberately make them share the same DepenencyManager and Store.
+	p.PagesFromTemplateOptions.Site = s
+	p.PagesFromTemplateDeps = p.PagesFromTemplateOptions.DepsFromSite(s)
+	p.buildState = &BuildState{
+		sourceInfosCurrent: maps.NewCache[string, *sourceInfo](),
+	}
+	return &p
+}
+
+func (p PagesFromTemplate) CloneForGoTmpl(fi hugofs.FileMetaInfo) *PagesFromTemplate {
+	p.PagesFromTemplateOptions.GoTmplFi = fi
+	return &p
+}
+
+func (p *PagesFromTemplate) GetDependencyManagerForScope(scope int) identity.Manager {
+	return p.DependencyManager
+}
+
+func (p *PagesFromTemplate) Execute(ctx context.Context) (BuildInfo, error) {
+	defer func() {
+		p.buildState.PrepareNextBuild()
+	}()
+
+	f, err := p.GoTmplFi.Meta().Open()
+	if err != nil {
+		return BuildInfo{}, err
+	}
+	defer f.Close()
+
+	tmpl, err := p.TmplFinder.Parse(filepath.ToSlash(p.GoTmplFi.Meta().Filename), helpers.ReaderToString(f))
+	if err != nil {
+		return BuildInfo{}, err
+	}
+
+	data := &pagesFromDataTemplateContext{
+		p: p,
+	}
+
+	ctx = tpl.Context.DependencyManagerScopedProvider.Set(ctx, p)
+
+	if err := p.TmplExec.ExecuteWithContext(ctx, tmpl, io.Discard, data); err != nil {
+		return BuildInfo{}, err
+	}
+
+	if p.Watching {
+		p.buildState.resolveDeletedPaths()
+	}
+
+	bi := BuildInfo{
+		NumPagesAdded:      p.buildState.NumPagesAdded,
+		NumResourcesAdded:  p.buildState.NumResourcesAdded,
+		EnableAllLanguages: p.buildState.EnableAllLanguages,
+		ChangedIdentities:  p.buildState.ChangedIdentities,
+		DeletedPaths:       p.buildState.DeletedPaths,
+		Path:               p.GoTmplFi.Meta().PathInfo,
+	}
+
+	return bi, nil
+}
+
+//////////////
diff --git a/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go b/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go
new file mode 100644
index 000000000..60930321a
--- /dev/null
+++ b/hugolib/pagesfromdata/pagesfromgotmpl_integration_test.go
@@ -0,0 +1,479 @@
+// Copyright 2024 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pagesfromdata_test
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+	"github.com/gohugoio/hugo/hugolib"
+	"github.com/gohugoio/hugo/markup/asciidocext"
+	"github.com/gohugoio/hugo/markup/pandoc"
+	"github.com/gohugoio/hugo/markup/rst"
+)
+
+const filesPagesFromDataTempleBasic = `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+disableLiveReload = true
+-- assets/a/pixel.png --
+iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==
+-- assets/mydata.yaml --
+p1: "p1"
+draft: false
+-- layouts/partials/get-value.html --
+{{ $val := "p1" }}
+{{ return $val }}
+-- layouts/_default/single.html --
+Single: {{ .Title }}|{{ .Content }}|Params: {{ .Params.param1 }}|Path: {{ .Path }}|
+Dates: Date: {{ .Date.Format "2006-01-02" }}|Lastmod: {{ .Lastmod.Format "2006-01-02" }}|PublishDate: {{ .PublishDate.Format "2006-01-02" }}|ExpiryDate: {{ .ExpiryDate.Format "2006-01-02" }}|
+Len Resources: {{ .Resources | len }}
+Resources: {{ range .Resources }}RelPermalink: {{ .RelPermalink }}|Name: {{ .Name }}|Title: {{ .Title }}|Params: {{ .Params }}|{{ end }}$
+{{ with .Resources.Get "featured.png" }}
+Featured Image: {{ .RelPermalink }}|{{ .Name }}|
+{{ with .Resize "10x10" }}
+Resized Featured Image: {{ .RelPermalink }}|{{ .Width }}|
+{{ end}}
+{{ end }}
+-- layouts/_default/list.html --
+List: {{ .Title }}|{{ .Content }}|
+RegularPagesRecursive: {{ range .RegularPagesRecursive }}{{ .Title }}:{{ .Path }}|{{ end }}$
+Sections: {{ range .Sections }}{{ .Title }}:{{ .Path }}|{{ end }}$
+-- content/docs/pfile.md --
+---
+title: "pfile"
+date: 2023-03-01
+---
+Pfile Content
+-- content/docs/_content.gotmpl --
+{{ $pixel := resources.Get "a/pixel.png" }}
+{{ $dataResource := resources.Get "mydata.yaml" }}
+{{ $data := $dataResource | transform.Unmarshal }}
+{{ $pd := $data.p1 }}
+{{ $pp := partial "get-value.html" }}
+{{ $title := printf "%s:%s" $pd $pp }}
+{{ $date := "2023-03-01" | time.AsTime }}
+{{ $dates := dict "date" $date }}
+{{ $contentMarkdown := dict "value" "**Hello World**"  "mediaType" "text/markdown" }}
+{{ $contentMarkdownDefault := dict "value" "**Hello World Default**" }}
+{{ $contentHTML := dict "value" "<b>Hello World!</b> No **markdown** here." "mediaType" "text/html" }}
+{{ $.AddPage  (dict "kind" "page" "path" "P1" "title" $title "dates" $dates "content" $contentMarkdown "params" (dict "param1" "param1v" ) ) }}
+{{ $.AddPage  (dict "kind" "page" "path" "p2" "title" "p2title" "dates" $dates "content" $contentHTML ) }}
+{{ $.AddPage  (dict "kind" "page" "path" "p3" "title" "p3title" "dates" $dates "content" $contentMarkdownDefault "draft" false ) }}
+{{ $.AddPage  (dict "kind" "page" "path" "p4" "title" "p4title" "dates" $dates "content" $contentMarkdownDefault "draft" $data.draft ) }}
+
+
+{{ $resourceContent := dict "value" $dataResource }}
+{{ $.AddResource (dict "path" "p1/data1.yaml" "content" $resourceContent) }}
+{{ $.AddResource (dict "path" "p1/mytext.txt" "content" (dict "value" "some text") "name" "textresource" "title" "My Text Resource" "params" (dict "param1" "param1v") )}}
+{{ $.AddResource (dict "path" "p1/sub/mytex2.txt" "content" (dict "value" "some text") "title" "My Text Sub Resource" ) }}
+{{ $.AddResource (dict "path" "P1/Sub/MyMixCaseText2.txt" "content" (dict "value" "some text") "title" "My Text Sub Mixed Case Path Resource" ) }}
+{{ $.AddResource (dict "path" "p1/sub/data1.yaml" "content" $resourceContent "title" "Sub data") }}
+{{ $resourceParams := dict "data2ParaM1" "data2Param1v" }}
+{{ $.AddResource (dict "path" "p1/data2.yaml" "name" "data2.yaml" "title" "My data 2" "params" $resourceParams "content" $resourceContent) }}
+{{ $.AddResource (dict "path" "p1/featuredimage.png" "name" "featured.png" "title" "My Featured Image" "params" $resourceParams "content" (dict "value" $pixel ))}}
+`
+
+func TestPagesFromGoTmplMisc(t *testing.T) {
+	t.Parallel()
+	b := hugolib.Test(t, filesPagesFromDataTempleBasic)
+	b.AssertPublishDir(`
+docs/p1/mytext.txt
+docs/p1/sub/mytex2.tx
+docs/p1/sub/mymixcasetext2.txt
+	`)
+
+	// Page from markdown file.
+	b.AssertFileContent("public/docs/pfile/index.html", "Dates: Date: 2023-03-01|Lastmod: 2023-03-01|PublishDate: 2023-03-01|ExpiryDate: 0001-01-01|")
+	// Pages from gotmpl.
+	b.AssertFileContent("public/docs/p1/index.html",
+		"Single: p1:p1|",
+		"Path: /docs/p1|",
+		"<strong>Hello World</strong>",
+		"Params: param1v|",
+		"Len Resources: 7",
+		"RelPermalink: /mydata.yaml|Name: data1.yaml|Title: data1.yaml|Params: map[]|",
+		"RelPermalink: /mydata.yaml|Name: data2.yaml|Title: My data 2|Params: map[data2param1:data2Param1v]|",
+		"RelPermalink: /a/pixel.png|Name: featured.png|Title: My Featured Image|Params: map[data2param1:data2Param1v]|",
+		"RelPermalink: /docs/p1/sub/mytex2.txt|Name: sub/mytex2.txt|",
+		"RelPermalink: /docs/p1/sub/mymixcasetext2.txt|Name: sub/mymixcasetext2.txt|",
+		"RelPermalink: /mydata.yaml|Name: sub/data1.yaml|Title: Sub data|Params: map[]|",
+		"Featured Image: /a/pixel.png|featured.png|",
+		"Resized Featured Image: /a/pixel_hu8aa3346827e49d756ff4e630147c42b5_70_10x10_resize_box_3.png|10|",
+		// Resource from string
+		"RelPermalink: /docs/p1/mytext.txt|Name: textresource|Title: My Text Resource|Params: map[param1:param1v]|",
+		// Dates
+		"Dates: Date: 2023-03-01|Lastmod: 2023-03-01|PublishDate: 2023-03-01|ExpiryDate: 0001-01-01|",
+	)
+	b.AssertFileContent("public/docs/p2/index.html", "Single: p2title|", "<b>Hello World!</b> No **markdown** here.")
+	b.AssertFileContent("public/docs/p3/index.html", "<strong>Hello World Default</strong>")
+}
+
+func TestPagesFromGoTmplAsciidocAndSimilar(t *testing.T) {
+	files := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+[security]
+[security.exec]
+allow = ['asciidoctor', 'pandoc','rst2html', 'python']
+-- layouts/_default/single.html --
+|Content: {{ .Content }}|Title: {{ .Title }}|Path: {{ .Path }}|
+-- content/docs/_content.gotmpl --
+{{ $.AddPage (dict "path" "asciidoc" "content" (dict "value" "Mark my words, #automation is essential#." "mediaType" "text/asciidoc" )) }}
+{{ $.AddPage (dict "path" "pandoc" "content" (dict "value" "This ~~is deleted text.~~" "mediaType" "text/pandoc" )) }}
+{{ $.AddPage (dict "path" "rst" "content" (dict "value" "This is *bold*." "mediaType" "text/rst" )) }}
+{{ $.AddPage (dict "path" "org" "content" (dict "value" "the ability to use +strikethrough+ is a plus" "mediaType" "text/org" )) }}
+{{ $.AddPage (dict "path" "nocontent" "title" "No Content" ) }}
+
+	`
+
+	b := hugolib.Test(t, files)
+
+	if asciidocext.Supports() {
+		b.AssertFileContent("public/docs/asciidoc/index.html",
+			"Mark my words, <mark>automation is essential</mark>",
+			"Path: /docs/asciidoc|",
+		)
+	}
+	if pandoc.Supports() {
+		b.AssertFileContent("public/docs/pandoc/index.html",
+			"This <del>is deleted text.</del>",
+			"Path: /docs/pandoc|",
+		)
+	}
+
+	if rst.Supports() {
+		b.AssertFileContent("public/docs/rst/index.html",
+			"This is <em>bold</em>",
+			"Path: /docs/rst|",
+		)
+	}
+
+	b.AssertFileContent("public/docs/org/index.html",
+		"the ability to use <del>strikethrough</del> is a plus",
+		"Path: /docs/org|",
+	)
+
+	b.AssertFileContent("public/docs/nocontent/index.html", "|Content: |Title: No Content|Path: /docs/nocontent|")
+}
+
+func TestPagesFromGoTmplAddPageErrors(t *testing.T) {
+	filesTemplate := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- content/docs/_content.gotmpl --
+{{ $.AddPage  DICT }}
+`
+
+	t.Run("AddPage, missing Path", func(t *testing.T) {
+		files := strings.ReplaceAll(filesTemplate, "DICT", `(dict "kind" "page" "title" "p1")`)
+		b, err := hugolib.TestE(t, files)
+		b.Assert(err, qt.IsNotNil)
+		b.Assert(err.Error(), qt.Contains, "_content.gotmpl:1:4")
+		b.Assert(err.Error(), qt.Contains, "error calling AddPage: path not set")
+	})
+
+	t.Run("AddPage, path starting with slash", func(t *testing.T) {
+		files := strings.ReplaceAll(filesTemplate, "DICT", `(dict "kind" "page" "title" "p1" "path" "/foo")`)
+		b, err := hugolib.TestE(t, files)
+		b.Assert(err, qt.IsNotNil)
+		b.Assert(err.Error(), qt.Contains, `path "/foo" must not start with a /`)
+	})
+
+	t.Run("AddPage, lang set", func(t *testing.T) {
+		files := strings.ReplaceAll(filesTemplate, "DICT", `(dict "kind" "page" "path" "p1" "lang" "en")`)
+		b, err := hugolib.TestE(t, files)
+		b.Assert(err, qt.IsNotNil)
+		b.Assert(err.Error(), qt.Contains, "_content.gotmpl:1:4")
+		b.Assert(err.Error(), qt.Contains, "error calling AddPage: lang must not be set")
+	})
+
+	t.Run("Site methods not ready", func(t *testing.T) {
+		filesTemplate := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- content/docs/_content.gotmpl --
+{{ .Site.METHOD }}
+`
+
+		for _, method := range []string{"RegularPages", "Pages", "AllPages", "AllRegularPages", "Home", "Sections", "GetPage", "Menus", "MainSections", "Taxonomies"} {
+			t.Run(method, func(t *testing.T) {
+				files := strings.ReplaceAll(filesTemplate, "METHOD", method)
+				b, err := hugolib.TestE(t, files)
+				b.Assert(err, qt.IsNotNil)
+				b.Assert(err.Error(), qt.Contains, fmt.Sprintf("error calling %s: this method cannot be called before the site is fully initialized", method))
+			})
+		}
+	})
+}
+
+func TestPagesFromGoTmplAddResourceErrors(t *testing.T) {
+	filesTemplate := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- content/docs/_content.gotmpl --
+{{ $.AddResource  DICT }}
+`
+
+	t.Run("missing Path", func(t *testing.T) {
+		files := strings.ReplaceAll(filesTemplate, "DICT", `(dict "name" "r1")`)
+		b, err := hugolib.TestE(t, files)
+		b.Assert(err, qt.IsNotNil)
+		b.Assert(err.Error(), qt.Contains, "error calling AddResource: path not set")
+	})
+}
+
+func TestPagesFromGoTmplEditGoTmpl(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.EditFileReplaceAll("content/docs/_content.gotmpl", `"title" "p2title"`, `"title" "p2titleedited"`).Build()
+	b.AssertFileContent("public/docs/p2/index.html", "Single: p2titleedited|")
+	b.AssertFileContent("public/docs/index.html", "p2titleedited")
+}
+
+func TestPagesFromGoTmplEditDataResource(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.AssertRenderCountPage(7)
+	b.EditFileReplaceAll("assets/mydata.yaml", "p1: \"p1\"", "p1: \"p1edited\"").Build()
+	b.AssertFileContent("public/docs/p1/index.html", "Single: p1edited:p1|")
+	b.AssertFileContent("public/docs/index.html", "p1edited")
+	b.AssertRenderCountPage(3)
+}
+
+func TestPagesFromGoTmplEditPartial(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.EditFileReplaceAll("layouts/partials/get-value.html", "p1", "p1edited").Build()
+	b.AssertFileContent("public/docs/p1/index.html", "Single: p1:p1edited|")
+	b.AssertFileContent("public/docs/index.html", "p1edited")
+}
+
+func TestPagesFromGoTmplRemovePage(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.EditFileReplaceAll("content/docs/_content.gotmpl", `{{ $.AddPage  (dict "kind" "page" "path" "p2" "title" "p2title" "dates" $dates "content" $contentHTML ) }}`, "").Build()
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$")
+}
+
+func TestPagesFromGoTmplDraftPage(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.EditFileReplaceAll("content/docs/_content.gotmpl", `"draft" false`, `"draft" true`).Build()
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p4title:/docs/p4|pfile:/docs/pfile|$")
+}
+
+func TestPagesFromGoTmplDraftFlagFromResource(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.EditFileReplaceAll("assets/mydata.yaml", `draft: false`, `draft: true`).Build()
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p3title:/docs/p3|pfile:/docs/pfile|$")
+	b.EditFileReplaceAll("assets/mydata.yaml", `draft: true`, `draft: false`).Build()
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$")
+}
+
+func TestPagesFromGoTmplMovePage(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$")
+	b.EditFileReplaceAll("content/docs/_content.gotmpl", `"path" "p2"`, `"path" "p2moved"`).Build()
+	b.AssertFileContent("public/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2moved|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$")
+}
+
+func TestPagesFromGoTmplRemoveGoTmpl(t *testing.T) {
+	t.Parallel()
+	b := hugolib.TestRunning(t, filesPagesFromDataTempleBasic)
+	b.AssertFileContent("public/index.html",
+		"RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$",
+		"Sections: Docs:/docs|",
+	)
+	b.AssertFileContent("public/docs/index.html", "RegularPagesRecursive: p1:p1:/docs/p1|p2title:/docs/p2|p3title:/docs/p3|p4title:/docs/p4|pfile:/docs/pfile|$")
+	b.RemoveFiles("content/docs/_content.gotmpl").Build()
+	// One regular page left.
+	b.AssertFileContent("public/index.html",
+		"RegularPagesRecursive: pfile:/docs/pfile|$",
+		"Sections: Docs:/docs|",
+	)
+	b.AssertFileContent("public/docs/index.html", "RegularPagesRecursive: pfile:/docs/pfile|$")
+}
+
+func TestPagesFromGoTmplLanguagePerFile(t *testing.T) {
+	filesTemplate := `
+-- hugo.toml --
+defaultContentLanguage = "en"
+defaultContentLanguageInSubdir = true
+[languages]
+[languages.en]
+weight = 1
+title = "Title"
+[languages.fr]
+weight = 2
+title = "Titre"
+disabled = DISABLE
+-- layouts/_default/single.html --
+Single: {{ .Title }}|{{ .Content }}|
+-- content/docs/_content.gotmpl --
+{{ $.AddPage  (dict "kind" "page" "path" "p1" "title" "Title" ) }}
+-- content/docs/_content.fr.gotmpl --
+{{ $.AddPage  (dict "kind" "page" "path" "p1" "title" "Titre" ) }}
+`
+
+	for _, disable := range []bool{false, true} {
+		t.Run(fmt.Sprintf("disable=%t", disable), func(t *testing.T) {
+			b := hugolib.Test(t, strings.ReplaceAll(filesTemplate, "DISABLE", fmt.Sprintf("%t", disable)))
+			b.AssertFileContent("public/en/docs/p1/index.html", "Single: Title||")
+			b.AssertFileExists("public/fr/docs/p1/index.html", !disable)
+			if !disable {
+				b.AssertFileContent("public/fr/docs/p1/index.html", "Single: Titre||")
+			}
+		})
+	}
+}
+
+func TestPagesFromGoTmplEnableAllLanguages(t *testing.T) {
+	t.Parallel()
+
+	filesTemplate := `
+-- hugo.toml --
+defaultContentLanguage = "en"
+defaultContentLanguageInSubdir = true
+[languages]
+[languages.en]
+weight = 1
+title = "Title"
+[languages.fr]
+title = "Titre"
+weight = 2
+disabled = DISABLE
+-- i18n/en.yaml --
+title: Title
+-- i18n/fr.yaml --
+title: Titre
+-- content/docs/_content.gotmpl --
+{{ .EnableAllLanguages }}
+{{ $titleFromStore := .Store.Get "title" }}
+{{ if not $titleFromStore }}
+	{{ $titleFromStore = "notfound"}}
+	{{ .Store.Set "title" site.Title }}
+{{ end }}
+{{ $title := printf "%s:%s:%s" site.Title (i18n "title") $titleFromStore }}
+{{ $.AddPage  (dict "kind" "page" "path" "p1" "title" $title ) }}
+--  layouts/_default/single.html --
+Single: {{ .Title }}|{{ .Content }}|
+
+`
+
+	for _, disable := range []bool{false, true} {
+		t.Run(fmt.Sprintf("disable=%t", disable), func(t *testing.T) {
+			b := hugolib.Test(t, strings.ReplaceAll(filesTemplate, "DISABLE", fmt.Sprintf("%t", disable)))
+			b.AssertFileExists("public/fr/docs/p1/index.html", !disable)
+			if !disable {
+				b.AssertFileContent("public/en/docs/p1/index.html", "Single: Title:Title:notfound||")
+				b.AssertFileContent("public/fr/docs/p1/index.html", "Single: Titre:Titre:Title||")
+			}
+		})
+	}
+}
+
+func TestPagesFromGoTmplMarkdownify(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- layouts/_default/single.html --
+|Content: {{ .Content }}|Title: {{ .Title }}|Path: {{ .Path }}|
+-- content/docs/_content.gotmpl --
+{{ $content := "**Hello World**" | markdownify }}
+{{ $.AddPage (dict "path" "p1" "content" (dict "value" $content "mediaType" "text/html" )) }}
+`
+
+	b, err := hugolib.TestE(t, files)
+
+	// This currently fails. We should fix this, but that is not a trivial task, so do it later.
+	b.Assert(err, qt.IsNotNil)
+	b.Assert(err.Error(), qt.Contains, "error calling markdownify: this method cannot be called before the site is fully initialized")
+}
+
+func TestPagesFromGoTmplResourceWithoutExtensionWithMediaTypeProvided(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- layouts/_default/single.html --
+|Content: {{ .Content }}|Title: {{ .Title }}|Path: {{ .Path }}|
+{{ range .Resources }}
+|RelPermalink: {{ .RelPermalink }}|Name: {{ .Name }}|Title: {{ .Title }}|Params: {{ .Params }}|MediaType: {{ .MediaType }}|
+{{ end }}
+-- content/docs/_content.gotmpl --
+{{ $.AddPage (dict "path" "p1" "content" (dict "value" "**Hello World**" "mediaType" "text/markdown" )) }}
+{{ $.AddResource (dict "path" "p1/myresource" "content" (dict "value" "abcde" "mediaType" "text/plain" )) }}
+`
+
+	b := hugolib.Test(t, files)
+
+	b.AssertFileContent("public/docs/p1/index.html", "RelPermalink: /docs/p1/myresource|Name: myresource|Title: myresource|Params: map[]|MediaType: text/plain|")
+}
+
+func TestPagesFromGoTmplCascade(t *testing.T) {
+	t.Parallel()
+
+	files := ` 
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- layouts/_default/single.html --
+|Content: {{ .Content }}|Title: {{ .Title }}|Path: {{ .Path }}|Params: {{ .Params }}|
+-- content/_content.gotmpl --
+{{ $cascade := dict "params" (dict "cascadeparam1" "cascadeparam1value" ) }}
+{{ $.AddPage (dict "path" "docs" "kind" "section" "cascade" $cascade ) }}
+{{ $.AddPage (dict "path" "docs/p1" "content" (dict "value" "**Hello World**" "mediaType" "text/markdown" )) }}
+
+`
+	b := hugolib.Test(t, files)
+
+	b.AssertFileContent("public/docs/p1/index.html", "|Path: /docs/p1|Params: map[cascadeparam1:cascadeparam1value")
+}
+
+func TestPagesFromGoBuildOptions(t *testing.T) {
+	t.Parallel()
+
+	files := ` 
+-- hugo.toml --
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+baseURL = "https://example.com"
+-- layouts/_default/single.html --
+|Content: {{ .Content }}|Title: {{ .Title }}|Path: {{ .Path }}|Params: {{ .Params }}|
+-- content/_content.gotmpl --
+{{ $.AddPage (dict "path" "docs/p1" "content" (dict "value" "**Hello World**" "mediaType" "text/markdown" )) }}
+{{ $never := dict "list" "never"  "publishResources" false "render" "never"  }}
+{{ $.AddPage (dict "path" "docs/p2" "content" (dict "value" "**Hello World**" "mediaType" "text/markdown" ) "build" $never ) }}
+
+
+`
+	b := hugolib.Test(t, files)
+
+	b.AssertFileExists("public/docs/p1/index.html", true)
+	b.AssertFileExists("public/docs/p2/index.html", false)
+}
diff --git a/hugolib/pagesfromdata/pagesfromgotmpl_test.go b/hugolib/pagesfromdata/pagesfromgotmpl_test.go
new file mode 100644
index 000000000..c60b56dbf
--- /dev/null
+++ b/hugolib/pagesfromdata/pagesfromgotmpl_test.go
@@ -0,0 +1,32 @@
+// Copyright 2024 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pagesfromdata
+
+import "testing"
+
+func BenchmarkHash(b *testing.B) {
+	m := map[string]any{
+		"foo":         "bar",
+		"bar":         "foo",
+		"stringSlice": []any{"a", "b", "c"},
+		"intSlice":    []any{1, 2, 3},
+		"largeText":   "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit.",
+	}
+
+	bs := BuildState{}
+
+	for i := 0; i < b.N; i++ {
+		bs.hash(m)
+	}
+}
diff --git a/hugolib/shortcode.go b/hugolib/shortcode.go
index af4454a89..8a478c9df 100644
--- a/hugolib/shortcode.go
+++ b/hugolib/shortcode.go
@@ -321,7 +321,7 @@ func prepareShortcode(
 
 	// Allow the caller to delay the rendering of the shortcode if needed.
 	var fn shortcodeRenderFunc = func(ctx context.Context) ([]byte, bool, error) {
-		if p.m.pageConfig.IsGoldmark && sc.doMarkup {
+		if p.m.pageConfig.ContentMediaType.IsMarkdown() && sc.doMarkup {
 			// Signal downwards that the content rendered will be
 			// parsed and rendered by Goldmark.
 			ctx = tpl.Context.IsInGoldmark.Set(ctx, true)
@@ -449,7 +449,7 @@ func doRenderShortcode(
 			//     unchanged.
 			// 2   If inner does not have a newline, strip the wrapping <p> block and
 			//     the newline.
-			switch p.m.pageConfig.Markup {
+			switch p.m.pageConfig.Content.Markup {
 			case "", "markdown":
 				if match, _ := regexp.MatchString(innerNewlineRegexp, inner); !match {
 					cleaner, err := regexp.Compile(innerCleanupRegexp)
diff --git a/hugolib/site.go b/hugolib/site.go
index 280387838..d9103e737 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -62,6 +62,7 @@ import (
 )
 
 func (s *Site) Taxonomies() page.TaxonomyList {
+	s.checkReady()
 	s.init.taxonomies.Do(context.Background())
 	return s.taxonomies
 }
@@ -204,6 +205,7 @@ type siteRenderingContext struct {
 }
 
 func (s *Site) Menus() navigation.Menus {
+	s.checkReady()
 	s.init.menus.Do(context.Background())
 	return s.menus
 }
@@ -372,19 +374,33 @@ func (s *Site) watching() bool {
 type whatChanged struct {
 	mu sync.Mutex
 
-	contentChanged bool
-	identitySet    identity.Identities
+	needsPagesAssembly bool
+	identitySet        identity.Identities
 }
 
 func (w *whatChanged) Add(ids ...identity.Identity) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 
+	if w.identitySet == nil {
+		w.identitySet = make(identity.Identities)
+	}
+
 	for _, id := range ids {
 		w.identitySet[id] = true
 	}
 }
 
+func (w *whatChanged) Clear() {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	w.clear()
+}
+
+func (w *whatChanged) clear() {
+	w.identitySet = identity.Identities{}
+}
+
 func (w *whatChanged) Changes() []identity.Identity {
 	if w == nil || w.identitySet == nil {
 		return nil
@@ -392,6 +408,14 @@ func (w *whatChanged) Changes() []identity.Identity {
 	return w.identitySet.AsSlice()
 }
 
+func (w *whatChanged) Drain() []identity.Identity {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	ids := w.identitySet.AsSlice()
+	w.clear()
+	return ids
+}
+
 // RegisterMediaTypes will register the Site's media types in the mime
 // package, so it will behave correctly with Hugo's built-in server.
 func (s *Site) RegisterMediaTypes() {
@@ -786,6 +810,7 @@ func (s *Site) errorCollator(results <-chan error, errs chan<- error) {
 // as possible for existing sites. Most sites will use {{ .Site.GetPage "section" "my/section" }},
 // i.e. 2 arguments, so we test for that.
 func (s *Site) GetPage(ref ...string) (page.Page, error) {
+	s.checkReady()
 	p, err := s.s.getPageForRefs(ref...)
 
 	if p == nil {
diff --git a/hugolib/site_new.go b/hugolib/site_new.go
index 496889295..788b80a3f 100644
--- a/hugolib/site_new.go
+++ b/hugolib/site_new.go
@@ -32,6 +32,7 @@ import (
 	"github.com/gohugoio/hugo/config/allconfig"
 	"github.com/gohugoio/hugo/deps"
 	"github.com/gohugoio/hugo/hugolib/doctree"
+	"github.com/gohugoio/hugo/hugolib/pagesfromdata"
 	"github.com/gohugoio/hugo/identity"
 	"github.com/gohugoio/hugo/langs"
 	"github.com/gohugoio/hugo/langs/i18n"
@@ -51,7 +52,15 @@ import (
 
 var _ page.Site = (*Site)(nil)
 
+type siteState int
+
+const (
+	siteStateInit siteState = iota
+	siteStateReady
+)
+
 type Site struct {
+	state     siteState
 	conf      *allconfig.Config
 	language  *langs.Language
 	languagei int
@@ -166,7 +175,8 @@ func NewHugoSites(cfg deps.DepsCfg) (*HugoSites, error) {
 		treeResources: doctree.New(
 			treeConfig,
 		),
-		treeTaxonomyEntries: doctree.NewTreeShiftTree[*weightedContentNode](doctree.DimensionLanguage.Index(), len(confm.Languages)),
+		treeTaxonomyEntries:           doctree.NewTreeShiftTree[*weightedContentNode](doctree.DimensionLanguage.Index(), len(confm.Languages)),
+		treePagesFromTemplateAdapters: doctree.NewTreeShiftTree[*pagesfromdata.PagesFromTemplate](doctree.DimensionLanguage.Index(), len(confm.Languages)),
 	}
 
 	pageTrees.createMutableTrees()
@@ -415,6 +425,7 @@ func (s *Site) Current() page.Site {
 
 // MainSections returns the list of main sections.
 func (s *Site) MainSections() []string {
+	s.checkReady()
 	return s.conf.C.MainSections
 }
 
@@ -433,6 +444,7 @@ func (s *Site) BaseURL() string {
 
 // Deprecated: Use .Site.Lastmod instead.
 func (s *Site) LastChange() time.Time {
+	s.checkReady()
 	hugo.Deprecate(".Site.LastChange", "Use .Site.Lastmod instead.", "v0.123.0")
 	return s.lastmod
 }
@@ -521,6 +533,7 @@ func (s *Site) ForEeachIdentityByName(name string, f func(identity.Identity) boo
 // Pages returns all pages.
 // This is for the current language only.
 func (s *Site) Pages() page.Pages {
+	s.checkReady()
 	return s.pageMap.getPagesInSection(
 		pageMapQueryPagesInSection{
 			pageMapQueryPagesBelowPath: pageMapQueryPagesBelowPath{
@@ -537,6 +550,7 @@ func (s *Site) Pages() page.Pages {
 // RegularPages returns all the regular pages.
 // This is for the current language only.
 func (s *Site) RegularPages() page.Pages {
+	s.checkReady()
 	return s.pageMap.getPagesInSection(
 		pageMapQueryPagesInSection{
 			pageMapQueryPagesBelowPath: pageMapQueryPagesBelowPath{
@@ -551,10 +565,18 @@ func (s *Site) RegularPages() page.Pages {
 
 // AllPages returns all pages for all sites.
 func (s *Site) AllPages() page.Pages {
+	s.checkReady()
 	return s.h.Pages()
 }
 
 // AllRegularPages returns all regular pages for all sites.
 func (s *Site) AllRegularPages() page.Pages {
+	s.checkReady()
 	return s.h.RegularPages()
 }
+
+func (s *Site) checkReady() {
+	if s.state != siteStateReady {
+		panic("this method cannot be called before the site is fully initialized")
+	}
+}
diff --git a/hugolib/site_sections.go b/hugolib/site_sections.go
index 1ce091f59..03d662b9f 100644
--- a/hugolib/site_sections.go
+++ b/hugolib/site_sections.go
@@ -19,10 +19,12 @@ import (
 
 // Sections returns the top level sections.
 func (s *Site) Sections() page.Pages {
+	s.checkReady()
 	return s.Home().Sections()
 }
 
 // Home is a shortcut to the home page, equivalent to .Site.GetPage "home".
 func (s *Site) Home() page.Page {
+	s.checkReady()
 	return s.s.home
 }