1 files changed, 219 insertions, 0 deletions
diff --git a/markup/goldmark/passthrough/passthrough.go b/markup/goldmark/passthrough/passthrough.go
new file mode 100644
index 000000000..20e42211e
--- /dev/null
+++ b/markup/goldmark/passthrough/passthrough.go
@@ -0,0 +1,219 @@
+// 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 passthrough
+
+import (
+	"bytes"
+	"sync"
+
+	htext "github.com/gohugoio/hugo/common/text"
+
+	"github.com/gohugoio/hugo-goldmark-extensions/passthrough"
+	"github.com/gohugoio/hugo/markup/converter/hooks"
+	"github.com/gohugoio/hugo/markup/goldmark/goldmark_config"
+	"github.com/gohugoio/hugo/markup/goldmark/internal/render"
+	"github.com/gohugoio/hugo/markup/internal/attributes"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/util"
+)
+
+func New(cfg goldmark_config.Passthrough) goldmark.Extender {
+	if !cfg.Enable {
+		return nil
+	}
+	return &passthroughExtension{cfg: cfg}
+}
+
+type (
+	passthroughExtension struct {
+		cfg goldmark_config.Passthrough
+	}
+	htmlRenderer struct{}
+)
+
+func (e *passthroughExtension) Extend(m goldmark.Markdown) {
+	configuredInlines := e.cfg.Delimiters.Inline
+	configuredBlocks := e.cfg.Delimiters.Block
+
+	inlineDelimiters := make([]passthrough.Delimiters, len(configuredInlines))
+	blockDelimiters := make([]passthrough.Delimiters, len(configuredBlocks))
+
+	for i, d := range configuredInlines {
+		inlineDelimiters[i] = passthrough.Delimiters{
+			Open:  d[0],
+			Close: d[1],
+		}
+	}
+
+	for i, d := range configuredBlocks {
+		blockDelimiters[i] = passthrough.Delimiters{
+			Open:  d[0],
+			Close: d[1],
+		}
+	}
+
+	pse := passthrough.New(
+		passthrough.Config{
+			InlineDelimiters: inlineDelimiters,
+			BlockDelimiters:  blockDelimiters,
+		},
+	)
+
+	pse.Extend(m)
+
+	// Set up render hooks if configured.
+	// Upstream passthrough inline = 101
+	// Upstream passthrough block = 99
+	m.Renderer().AddOptions(renderer.WithNodeRenderers(
+		util.Prioritized(newHTMLRenderer(), 90),
+	))
+}
+
+func newHTMLRenderer() renderer.NodeRenderer {
+	r := &htmlRenderer{}
+	return r
+}
+
+func (r *htmlRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(passthrough.KindPassthroughBlock, r.renderPassthroughBlock)
+	reg.Register(passthrough.KindPassthroughInline, r.renderPassthroughBlock)
+}
+
+func (r *htmlRenderer) renderPassthroughBlock(w util.BufWriter, src []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	ctx := w.(*render.Context)
+
+	if entering {
+		return ast.WalkContinue, nil
+	}
+
+	var (
+		s      string
+		typ    string
+		delims *passthrough.Delimiters
+	)
+
+	switch nn := node.(type) {
+	case *passthrough.PassthroughInline:
+		s = string(nn.Text(src))
+		typ = "inline"
+		delims = nn.Delimiters
+	case (*passthrough.PassthroughBlock):
+		l := nn.Lines().Len()
+		var buff bytes.Buffer
+		for i := 0; i < l; i++ {
+			line := nn.Lines().At(i)
+			buff.Write(line.Value(src))
+		}
+		s = buff.String()
+		typ = "block"
+		delims = nn.Delimiters
+	}
+
+	renderer := ctx.RenderContext().GetRenderer(hooks.PassthroughRendererType, typ)
+	if renderer == nil {
+		// Write the raw content if no renderer is found.
+		ctx.WriteString(s)
+		return ast.WalkContinue, nil
+	}
+
+	// Inline and block passthroughs share the same ordinal counter.
+	ordinal := ctx.GetAndIncrementOrdinal(passthrough.KindPassthroughBlock)
+
+	// Trim the delimiters.
+	s = s[len(delims.Open) : len(s)-len(delims.Close)]
+
+	pctx := &passthroughContext{
+		ordinal:          ordinal,
+		page:             ctx.DocumentContext().Document,
+		pageInner:        r.getPageInner(ctx),
+		inner:            s,
+		typ:              typ,
+		AttributesHolder: attributes.New(node.Attributes(), attributes.AttributesOwnerGeneral),
+	}
+
+	pctx.createPos = func() htext.Position {
+		if resolver, ok := renderer.(hooks.ElementPositionResolver); ok {
+			return resolver.ResolvePosition(pctx)
+		}
+		return htext.Position{
+			Filename:     ctx.DocumentContext().Filename,
+			LineNumber:   1,
+			ColumnNumber: 1,
+		}
+	}
+
+	pr := renderer.(hooks.PassthroughRenderer)
+
+	if err := pr.RenderPassthrough(ctx.RenderContext().Ctx, w, pctx); err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}
+
+func (r *htmlRenderer) getPageInner(rctx *render.Context) any {
+	pid := rctx.PeekPid()
+	if pid > 0 {
+		if lookup := rctx.DocumentContext().DocumentLookup; lookup != nil {
+			if v := rctx.DocumentContext().DocumentLookup(pid); v != nil {
+				return v
+			}
+		}
+	}
+	return rctx.DocumentContext().Document
+}
+
+type passthroughContext struct {
+	page      any
+	pageInner any
+	typ       string // inner or block
+	inner     string
+	ordinal   int
+
+	// This is only used in error situations and is expensive to create,
+	// so delay creation until needed.
+	pos       htext.Position
+	posInit   sync.Once
+	createPos func() htext.Position
+	*attributes.AttributesHolder
+}
+
+func (p *passthroughContext) Page() any {
+	return p.page
+}
+
+func (p *passthroughContext) PageInner() any {
+	return p.pageInner
+}
+
+func (p *passthroughContext) Type() string {
+	return p.typ
+}
+
+func (p *passthroughContext) Inner() string {
+	return p.inner
+}
+
+func (p *passthroughContext) Ordinal() int {
+	return p.ordinal
+}
+
+func (p *passthroughContext) Position() htext.Position {
+	p.posInit.Do(func() {
+		p.pos = p.createPos()
+	})
+	return p.pos
+}