path: root/docs/content/en/content-management/content-adapters.md

---
title: Content adapters
description: Create content adapters to dynamically add content when building your site.
categories: [content management]
keywords: []
menu:
  docs:
    parent: content-management
    weight: 290
weight: 290
toc: true
---

{{< new-in 0.126.0 >}}

## Overview

A content adapter is a template that dynamically creates pages when building a site. For example, use a content adapter to create pages from a remote data source such as JSON, TOML, YAML, or XML.

Unlike templates that reside in the layouts directory, content adapters reside in the content directory, no more than one per directory per language. When a content adapter creates a page, the page's [logical path] will be relative to the content adapter.

```text
content/
├── articles/
│   ├── _index.md
│   ├── article-1.md
│   └── article-2.md
├── books/
│   ├── _content.gotmpl  <-- content adapter
│   └── _index.md
└── films/
    ├── _content.gotmpl  <-- content adapter
    └── _index.md
```

Each content adapter is named _content.gotmpl and uses the same [syntax] as templates in the layouts directory. You can use any of the [template functions] within a content adapter, as well as the methods described below.

## Methods

Use these methods within a content adapter.

###### AddPage

Adds a page to the site.

{{< code file=content/books/_content.gotmpl >}}
{{ $content := dict
  "mediaType" "text/markdown"
  "value" "The _Hunchback of Notre Dame_ was written by Victor Hugo."
}}
{{ $page := dict
  "content" $content
  "kind" "page"
  "path" "the-hunchback-of-notre-dame"
  "title" "The Hunchback of Notre Dame"
}}
{{ .AddPage $page }}
{{< /code >}}

###### AddResource

Adds a page resource to the site.

{{< code file=content/books/_content.gotmpl >}}
{{ with resources.Get "images/a.jpg" }}
  {{ $content := dict
    "mediaType" .MediaType.Type
    "value" .
  }}
  {{ $resource := dict
    "content" $content
    "path" "the-hunchback-of-notre-dame/cover.jpg"
  }}
  {{ $.AddResource $resource }}
{{ end }}
{{< /code >}}

Then retrieve the new page resource with something like:

{{< code file=layouts/_default/single.html >}}
{{ with .Resources.Get "cover.jpg" }}
  <img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="">
{{ end }}
{{< /code >}}

###### Site

Returns the `Site` to which the pages will be added.

{{< code file=content/books/_content.gotmpl >}}
{{ .Site.Title }}
{{< /code >}}

{{% note %}}
Note that the `Site` returned isn't fully built when invoked from the content adapters; if you try to call methods that depends on pages, e.g. `.Site.Pages`, you will get an error saying "this method cannot be called before the site is fully initialized".
{{% /note %}}

###### Store

Returns a persistent “scratch pad” to store and manipulate data. The main use case for this is to transfer values between executions when [EnableAllLanguages](#enablealllanguages) is set. See [examples](/methods/page/store/).

{{< code file=content/books/_content.gotmpl >}}
{{ .Store.Set "key" "value" }}
{{ .Store.Get "key" }}
{{< /code >}}

###### EnableAllLanguages

By default, Hugo executes the content adapter for the language defined by the _content.gotmpl file . Use this method to activate the content adapter for all languages.

{{< code file=content/books/_content.gotmpl >}}
{{ .EnableAllLanguages }}
{{ $content := dict
  "mediaType" "text/markdown"
  "value" "The _Hunchback of Notre Dame_ was written by Victor Hugo."
}}
{{ $page := dict
  "content" $content
  "kind" "page"
  "path" "the-hunchback-of-notre-dame"
  "title" "The Hunchback of Notre Dame"
}}
{{ .AddPage $page }}
{{< /code >}}

## Page map

Set any [front matter field] in the map passed to the [`AddPage`](#addpage) method, excluding `markup`. Instead of setting the `markup` field, specify the `content.mediaType` as described below.

This table describes the fields most commonly passed to the `AddPage` method.

Key|Description|Required
:--|:--|:-:
`content.mediaType`|The content [media type]. Default is `text/markdown`. See [content formats] for examples.|&nbsp;
`content.value`|The content value as a string.|&nbsp;
`dates.date`|The page creation date as a `time.Time` value.|&nbsp;
`dates.expiryDate`|The page expiry date as a `time.Time` value.|&nbsp;
`dates.lastmod`|The page last modification date as a `time.Time` value.|&nbsp;
`dates.publishDate`|The page publication date as a `time.Time` value.|&nbsp;
`kind`|The [page kind]. Default is `page`.|&nbsp;
`params`|A map of page parameters.|&nbsp;
`path`|The page's [logical path] relative to the content adapter. Do not include a leading slash or file extension.|:heavy_check_mark:
`title`|The page title.|&nbsp;

{{% note %}}
While `path` is the only required field, we recommend setting `title` as well.

When setting the `path`, Hugo transforms the given string to a logical path. For example, setting `path` to `A B C` produces a logical path of `/section/a-b-c`.
{{% /note %}}

## Resource map

Construct the map passed to the [`AddResource`](#addresource) method using the fields below.

Key|Description|Required
:--|:--|:-:
`content.mediaType`|The content [media type].|:heavy_check_mark:
`content.value`|The content value as a string or resource.|:heavy_check_mark:
`name`|The resource name.|&nbsp;
`params`|A map of resource parameters.|&nbsp;
`path`|The resources's [logical path] relative to the content adapter. Do not include a leading slash.|:heavy_check_mark:
`title`|The resource title.|&nbsp;

{{% note %}}
If the `content.value` is a string Hugo creates a new resource. If the `content.value` is a resource, Hugo obtains the value from the existing resource.

When setting the `path`, Hugo transforms the given string to a logical path. For example, setting `path` to `A B C/cover.jpg` produces a logical path of `/section/a-b-c/cover.jpg`.
{{% /note %}}

## Example

Create pages from remote data, where each page represents a book review.

Step 1
: Create the content structure.

```text
content/
└── books/
    ├── _content.gotmpl  <-- content adapter
    └── _index.md
```

Step 2
: Inspect the remote data to determine how to map key-value pairs to front matter fields.

: <https://gohugo.io/shared/examples/data/books.json>

Step 3
: Create the content adapter.

{{< code file=content/books/_content.gotmpl copy=true >}}
{{/* Get remote data. */}}
{{ $data := dict }}
{{ $url := "https://gohugo.io/shared/examples/data/books.json" }}
{{ with resources.GetRemote $url }}
  {{ with .Err }}
    {{ errorf "Unable to get remote resource %s: %s" $url . }}
  {{ else }}
    {{ $data = . | transform.Unmarshal }}
  {{ end }}
{{ else }}
  {{ errorf "Unable to get remote resource %s" $url }}
{{ end }}

{{/* Add pages and page resources. */}}
{{ range $data }}

  {{/* Add page. */}}
  {{ $content := dict "mediaType" "text/markdown" "value" .summary }}
  {{ $dates := dict "date" (time.AsTime .date) }}
  {{ $params := dict "author" .author "isbn" .isbn "rating" .rating "tags" .tags }}
  {{ $page := dict
    "content" $content
    "dates" $dates
    "kind" "page"
    "params" $params
    "path" .title
    "title" .title
  }}
  {{ $.AddPage $page }}

  {{/* Add page resource. */}}
  {{ $item := . }}
  {{ with $url := $item.cover }}
    {{ with resources.GetRemote $url }}
      {{ with .Err }}
        {{ errorf "Unable to get remote resource %s: %s" $url . }}
      {{ else }}
        {{ $content := dict "mediaType" .MediaType.Type "value" .Content }}
        {{ $params := dict "alt" $item.title }}
        {{ $resource := dict
          "content" $content
          "params" $params
          "path" (printf "%s/cover.%s" $item.title .MediaType.SubType)
        }}
        {{ $.AddResource $resource }}
      {{ end }}
    {{ else }}
      {{ errorf "Unable to get remote resource %s" $url }}
    {{ end }}
  {{ end }}

{{ end }}
{{< /code >}}

Step 4
: Create a single template to render each book review.

{{< code file=layouts/books/single.html copy=true >}}
{{ define "main" }}
  <h1>{{ .Title }}</h1>

  {{ with .Resources.GetMatch "cover.*" }}
    <img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="{{ .Params.alt }}">
  {{ end }}

  <p>Author: {{ .Params.author }}</p>

  <p>
    ISBN: {{ .Params.isbn }}<br>
    Rating: {{ .Params.rating }}<br>
    Review date: {{ .Date | time.Format ":date_long" }}
  </p>

  {{ with .GetTerms "tags" }}
    <p>Tags:</p>
    <ul>
      {{ range . }}
        <li><a href="{{ .RelPermalink }}">{{ .LinkTitle }}</a></li>
      {{ end }}
    </ul>
  {{ end }}

  {{ .Content }}
{{ end }}
{{< /code >}}

## Multilingual sites

With multilingual sites you can:

1. Create one content adapter for all languages using the [`EnableAllLanguages`](#enablealllanguages) method as described above.
2. Create content adapters unique to each language. See the examples below.

### Translations by file name

With this site configuration:

{{< code-toggle file=hugo >}}
[languages.en]
weight = 1

[languages.de]
weight = 2
{{< /code-toggle >}}

Include a language designator in the content adapter's file name.

```text
content/
└── books/
    ├── _content.de.gotmpl
    ├── _content.en.gotmpl
    ├── _index.de.md
    └── _index.en.md
```

### Translations by content directory

With this site configuration:

{{< code-toggle file=hugo >}}
[languages.en]
contentDir = 'content/en'
weight = 1

[languages.de]
contentDir = 'content/de'
weight = 2
{{< /code-toggle >}}

Create a single content adapter in each directory:

```text
content/
├── de/
│   └── books/
│       ├── _content.gotmpl
│       └── _index.md
└── en/
    └── books/
        ├── _content.gotmpl
        └── _index.md
```

## Page collisions

Two or more pages collide when they have the same publication path. Due to concurrency, the content of the published page is indeterminate. Consider this example:

```text
content/
└── books/
    ├── _content.gotmpl  <-- content adapter
    ├── _index.md
    └── the-hunchback-of-notre-dame.md
```

If the content adapter also creates books/the-hunchback-of-notre-dame, the content of the published page is indeterminate. You can not define the processing order.

To detect page collisions, use the `--printPathWarnings` flag when building your site.

[content formats]: /content-management/formats/#classification
[front matter field]: /content-management/front-matter/#fields
[logical path]: /getting-started/glossary/#logical-path
[media type]: https://en.wikipedia.org/wiki/Media_type
[page kind]: /getting-started/glossary/#page-kind
[syntax]: /templates/introduction/
[template functions]: /functions/