contentful-hugo

Contentful Hugo

This is a simple Node.js CLI tool that pulls data from Contentful CMS and turns it into Markdown or YAML files for use with a static site generator. It can be used with any static site generator that uses Markdown with YAML frontmatter, but it has some features that are specific to Hugo.

Table of Contents

• Prerequisites
• Installation
• Usage
• Configuration
  • Environenment Variables
  • Config File(s)
• Expected Output
  • Standard Fields
  • Richtext Fields
  • Resolving Reference Fields
• Known Issues

Prerequisites

Install Node.js

Installation

with NPM

npm install contentful-hugo

with Yarn

yarn add contentful-hugo

Usage

Terminal Commands

Complete configuration then run the following command(s) in the terminal

When Installed Globally

## initialize the directory
contentful-hugo --init

## fetch from contentful
contentful-hugo

When Installed Locally

npx contentful-hugo --init
npx contentful-hugo

Flags

flag	aliases	description
--init		Initialize the directory. Generates a config file and default shortcodes for Contentful rich text fields
--preview	-P	Runs in preview mode, which pulls both published and unpublished entries from Contentful
--wait	-W	Wait for the specified number of milliseconds before pulling data from Contentful.
--config	-C	Specify the path to a config file.
--help		Show help
--version		Show version number

Preview Mode Example

contentful-hugo --preview

Multiple Flags Example

contentful-hugo --wait=2000 --preview --config="my_custom_config.js"

# or

contentful-hugo --wait 2000 --preview --config my_custom_config.js

Example Package.json

{
  "name": "my-hugo-project",
  "scripts": {
    "prestart": "contentful-hugo",
    "start": "hugo server",
    "prebuild": "contentful-hugo",
    "build": "hugo --minify"
  }
}

In this example when you run npm start it will first use contentful-hugo to pull Contentful data then start hugo server. In the same way when you do the command npm run build it will first use contentful-hugo to pull Contentful data then run hugo --minify to build a minified version of your hugo site.

Error Messages

Trying to use this package before completing configuration will return an error in the console

Error: There is an error in your config file, or it does't exits.
Check your config for errors or run "contentful-hugo --init" to create a config file.

Configuration

Environment Variables

By default this library will look for the following environment variables. You can also override these values with the config file. (See config)

• CONTENTFUL_SPACE
• CONTENTFUL_TOKEN
• CONTENTFUL_PREVIEW_TOKEN

.env File:

To declare these environment variables create a .env file in the root directory of your project.

CONTENTFUL_SPACE = '<space-id>'
CONTENTFUL_TOKEN = '<content-accessToken>'

# optional but required for preview mode
CONTENTFUL_PREVIEW_TOKEN = '<preview-accessToken>'

You can also declare the environment variables in the command line

Powershell:

$env:CONTENTFUL_SPACE="<contentful_space_id>"
$env:CONTENTFUL_TOKEN="<contentful_acessToken>"
$env:CONTENTFUL_PREVIEW_TOKEN="<contentful_preview_accessToken>"

Bash:

export CONTENTFUL_SPACE="<contentful_space_id>"
export CONTENTFUL_TOKEN="<contentful_accessToken>"
export CONTENTFUL_PREVIEW_TOKEN="<contentful_preview_accessToken>"

Config File

Before getting started, you will need to create a config file in the root of your repository. Contentful-hugo by default will search for the following files as a config.

• contentful-hugo.config.js
• contentful-hugo.config.yaml
• contentful-hugo.yaml
• contentful-settings.yaml

You can also specify a custom config file using the --config flag. (Javascript or YAML config files are the only currently accepted filetypes)

Example Javascript Config

// contentful-hugo.config.js

module.exports = {
    contentful: {
        // defaults to CONTENTFUL_SPACE env variable
        space: 'space-id',
        // defaults to CONTENTFUL_TOKEN env variable
        token: 'content-deliver-token',
        // defaults to CONTENTFUL_PREVIEW_TOKEN env variable
        previewToken: 'content-preview-token',
        // defaults to "master"
        environment: 'master',
    },
    singleTypes: [
        {
            id: 'homepage',
            directory: 'content',
            fileName: '_index',
            fileExtension: 'md',
        },
        {
            id: 'siteSettings',
            directory: 'data',
            fileName: 'settings',
            fileExtension: 'yaml',
        },
    ],
    repeatableTypes: [
        {
            id: 'posts',
            directory: 'content/posts',
            fileExtension: 'md',
            mainContent: 'content',
            resolveEntries: [
                {
                    field: 'categories',
                    resolveTo: 'fields.slug',
                },
                {
                    field: 'author',
                    resolveTo: 'fields.name',
                },
                {
                    field: 'relatedPosts',
                    resolveTo: 'sys.id',
                },
            ],
        },
        {
            id: 'seoFields',
            isHeadless: true,
            directory: 'content/seo-fields',
        },
        {
            id: 'reviews',
            directory: 'content/reviews',
            mainContent: 'reviewBody',
        },
        {
            id: 'category',
            directory: 'content/categories',
            isTaxonomy: true, // Experimental Feature
        },
    ],
};

Example YAML Config

# contentful-hugo.config.yaml

contentful:
    space: 'space-id' # defaults to CONTENTFUL_SPACE env variable
    token: 'content-deliver-token' # defaults to  CONTENTFUL_TOKEN env variable
    previewToken: 'content-preview-token' # defaults to  CONTENTFUL_PREVIEW_TOKEN env variable
    environment: 'master' # defaults to "master"

singleTypes:
    # fetches only the most recently updated entry in a particular content type
    # Generated file will be named after the fileName setting

    - id: homepage
      directory: content
      fileName: _index
      fileExtension: md

    - id: siteSettings
      directory: data
      fileName: settings
      fileExtension: yaml

repeatableTypes:
    # fetches all the entries of a content type and places them in a directory.
    # Generated files will be named after their Entry ID in Contentful.

    - id: posts
      directory: content/posts
      fileExtension: md
      mainContent: content
      resolveEntries: # resolves a reference or asset field to a specific property
          - field: categories
            resolveTo: fields.slug
          - field: author
            resolveTo: fields.name
          - field: relatedPosts
            resolveTo: sys.id

    - id: seoFields
      isHeadless: true
      directory: content/seo-fields

    - id: reviews
      directory: content/reviews
      mainContent: reviewBody

    - id: staff
      isHeadless: true
      directory: content/staff

    - id: category
      directory: content/categories
      isTaxonomy: true # Experimental Feature

Config Fields

Contentful Options

field	required	description
space	optional	Contentful Space ID (Defaults to CONTENTFUL_SPACE environment variable if not set)
token	optional	Content delivery token (Defaults to CONTENTFUL_TOKEN environment variable if not set)
previewToken	optional	Content preview token (Defaults to CONTENTFUL_PREVIEW_TOKEN environment variable if not set)
environment	optional	Contentful environment ID (Defaults to "master" if not set)

Single Type Options

field	required	description
id	required	Contentful content type ID
directory	required	Directory where you want the file(s) to be generated
fileName	required	Name of the file generated
fileExtension	optional	Can be "md", "yml", or "yaml" (defaults to "md")
mainContent	optional	Field ID for field you want to be the main Markdown content. (Can be a markdown, richtext, or string field)
type	optional	Manually set value for "type" field in the frontmatter (see hugo docs)
resolveEntries	optional	Resolve the specified reference fields and/or asset fields to one of it's properties specified with the resolveTo parameter
overrides	optional	Do custom overrides for field values or field names
filters	optional	Accepts an object of Contentful search parameters to filter results. See Contentful docs

Repeatable Type Options

field	required	description
id	required	Contentful content type ID
directory	required	Directory where you want the files to be generated
fileExtension	optional	Can be "md", "yml", or "yaml" (defaults to "md")
isHeadless	optional	Turns all entries in a content type into headless leaf bundles (see hugo docs). Cannot be set to true when isTaxonomy is set to true.
isTaxonomy (Experimental)	optional	Organize entries in file structure allowing for custom taxonomy metadata (see hugo docs). Cannot be set to true when isHeadless is set to true.
mainContent	optional	Field ID for field you want to be the main markdown content. (Can be a markdown, richtext, or string field)
type	optional	Manually set value for "type" field in the frontmatter (see hugo docs)
resolveEntries	optional	Resolve the specified reference fields and/or asset fields to one of it's properties specified with the resolveTo parameter
overrides	optional	Do custom overrides for field values or field names
filters	optional	Accepts an object of Contentful search parameters to filter results. See Contentful docs

Advanced Config Examples

Dynmically Changing Tokens

Here is an example of dynamically change the token, previewToken, and environment options depending on any arbitrary condition.

// contentful-hugo.config.js

require('dotenv').config(); // assuming you have "dotenv" in your dependencies

const myMasterToken = process.env.CONTENTFUL_MASTER_TOKEN;
const myMasterPreviewToken = process.env.CONTENTFUL_MASTER_PREVIEW_TOKEN;
const myStagingToken = process.env.CONTENTFUL_STAGING_TOKEN;
const myStagingPreviewToken = process.env.CONTENTFUL_STAGING_PREVIEW_TOKEN;

// set some condition
const isStaging = true || false;

module.exports = {
    contentful: {
        space: 'my-space-id',
        token: isStaging ? myStagingToken : myMasterToken,
        preview: isStaging ? myStagingPreviewToken : myMasterPreviewToken,
        environment: isStaging ? 'staging' : 'master',
    },
    // rest of config
};

Overriding Fields and Field Values

// contentful-hugo.config.js

module.exports = {
    repeatableTypes: [
        {
            id: "trips",
            directory: "content/trips"
            overrides: [{
                field: "url",
                options: {
                    // change the url field name to "slug" in frontmatter
                    fieldName: "slug"
                }
            },
            {
                field: "distanceInKilometers",
                options: {
                    // rename "distanceInKilometers" to "distanceInMiles"
                    fieldName: "distanceInMiles",
                    // convert distance to miles and output the result in frontmatter
                    valueTransformer: (val) => {
                        if(typeof val === 'number') {
                            return val * 0.621371
                        }
                        return 0
                    }
                }
            }]
        }
    ]
}

Config File Autocomplete

For JS config files you can import a ContentfulHugoConfig type which will enable autocomplete in text editors that support Typescript typings. (Tested in Visual Studio Code.)

/**
 * @type {import('contentful-hugo').ContentfulHugoConfig}
 */
module.exports = {
    // rest of config
};

Expected Output

Files will be generated in the directory specified in the config file. Front matter will be in YAML format. Files of single types will be named after fileName specified in the config file. Files of repeatable types will be named after their entry ID in Contenful, which makes it easy to link files together.

Default Date and Time Fields

The following fields will always appear in your frontmatter:

updated: # the last time this entry was update in Contentful
createdAt: # when the entry was created in Contentful
date: # defaults to creation date unless you have a field with the id "date" then it get's overwritten

Asset Information

Assets like images and videos come with some extra information that makes it easy to implement things like alt text or layouts that rely on knowing the image dimensions. The fields are as follows:

assetFieldName:
    assetType: # indicates the asset type such as "image" "video" "audio" ect.
    url: # url of the asset
    title: # title of the asset written in Contentful
    description: # description of the asset written in Contentful
    width: # width of the asset (images only)
    height: # height of the asset (images only )

If you're using Hugo you can access the information like below:

<img
    src="{{ .Params.assetFieldName.url }}"
    width="{{ .Params.assetFieldName.width }}"
/>

This same information will also appear in asset arrays like a gallery:

myGallery:
    - assetType: 'image/jpg'
      url: '//link-to-image.jpg'
      title: 'Image 1'
      description: 'Image 1 Description'
      width: 500
      height: 500
    - assetType: 'image/jpg'
      url: '//link-to-image-2.jpg'
      title: 'Image 2'
      description: 'Image 2 Description'
      width: 1920
      height: 1080

Entries

Linked entries will include fields for it's id and it's content type id.

linkedEntry:
    id: <contentful-entry-id>
    typeId: <content-type-ID>

#example with array of linked entries

relatedArticles:
    - id: '41UFfIhszbS1kh95bomMj7'
      typeId: 'articles'
    - id: '85UFfIhsacS1kh71bpqMj7'
      typeId: 'articles'

All files are named after their entry id in Contentful making it easy to retrieve it using .Site.GetPage in Hugo

{{ with .Site.GetPage "<path-to-file>/<entry-id>.md" }}
    {{ .Title }}
{{ end }}

Rich Text As Main Content

A rich text field that is set as the "mainContent" for a content type will be rendered as markdown for Hugo.

Dynamic content such as embedded-entry-blocks are rendered as shortcodes with parameters included that can be used to fetch the necessary data.

<!-- example embedded entry -->
<!-- you can use the id, contentType, and parentContentType parameters to fetch the desired data -->

{{< contentful-hugo/embedded-entry id="nTLo2ffSJJp5QrnrO5IU9" contentType="gallery" parentContentType="post" >}}

Before fetching rich text data make sure you have run contentful-hugo --init so that you will have all the rich text shortcodes. Once you have these shortcodes you can extend and modify them to suit your needs.

The list of rich text short codes includes:

• contentful-hugo/asset-hyperlink.html
• contentful-hugo/embedded-asset.html
• contentful-hugo/embedded-entry.html
• contentful-hugo/entry-hyperlink.html
• contentful-hugo/inline-entry.html

By default the richtext short codes will show a notification for an unconfigured item.

You can customize them by navigating to layouts/shortcodes/contentful-hugo/{shortcode-name}.html

Rich Text In FrontMatter

A Rich text field will produce nested arrays mirroring the JSON structure that they have in the API. Each node will need to be looped through and produce HTML depending on the nodeType field.

richTextField:
    - nodeType: 'paragraph'
      data: {}
      content:
          - data: {}
            marks: []
            value: 'This is a simple paragraph.'
            nodeType: 'text'
    - nodeType: 'paragraph'
      data: {}
      content:
          - data: {}
            marks: []
            value: 'This is a paragraph with '
            nodeType: 'text'
          - data: {}
            marks:
                - type: 'italic'
            value: 'italicized text.'
            nodeType: 'text'
    - nodeType: 'embedded-asset-block'
      data:
          assetType: 'image/jpeg'
          url: '//images.ctfassets.net/some-image-url.jpg'
          title: 'Image title will appear here'
          description: 'Image description will appear here'
          width: 1920
          height: 1080
      content: []

In addition a plaintext version of the field will be generated using the field ID appended with "_plaintext". This allows you to quickly fetch the text by itself without any of the other data. A simple use case would be using the plaintext output to automatically generate a meta description for a webpage.

richTextField_plaintext: 'This is a simple paragraph. This is a paragraph with italicized text.'

The Resolve Entries Parameter

The resolve entries option let's you specify a field from a referenced entry or asset to resolve that field value you. For example say you have a category content type that is referenced in posts. Normally contentful-hugo will give the following result

category:
    id: some-entry-id
    contentType: category

While this makes it easy to find the category, this format does not allow you to use Hugo's built in taxonomy features. With the resolveEntries parameter you can remedy this.

// from the config file
module.exports = {
    repeatableTypes: [
        {
            id: 'post',
            directory: 'content/posts',
            resolveEntries: [
                {
                    field: 'category',
                    resolveTo: 'fields.slug',
                },
            ],
        },
    ],
};

Now the category field will only display the slug as the value.

category: my-category-slug

The resolve entries feature works with both reference fields and asset fields. (As well as multiple reference and multiple asset fields)

The Overrides Parameter

Overrides can be used to modify field names and field values.

Here's a simple example of changing a field name from "url" to "videoUrl"

repeatableTypes: [
    {
        id: 'youtubeVideo',
        directory: 'content/_youtubeVideo',
        isHeadless: true,
        overrides: [
            {
                field: 'url',
                options: {
                    // change fieldname to videoUrl in order to prevent Hugo errors
                    fieldName: 'videoUrl',
                },
            },
        ],
    },
];

You can also use the overrides to transform the field data that will appear in frontmatter. Here's an example where we change the field name from "url" to "videoId" and then we use the valueTransformer to extract the video id from the url and then place it in the frontmatter.

repeatableTypes: [
    {
        id: 'youtubeVideo',
        directory: 'content/_youtubeVideo',
        isHeadless: true,
        overrides: [
            field: 'url',
            options: {
                fieldName: 'videoId',
                valueTransformer: (value) => {
                    const url = new URL(value)
                    // extract the video id from the url and return it
                    return url.searchParams.get('v')
                }
            }
        ]
    }
]

The Filters Parameter

You can use to filters option to enter search parameters allowing you to filter entries based on some of their properties. For more info on Contentful search parameters visit their docs.

Be aware that the following search parameters will be ignored content_type, skip, order, limit

Examples:

module.exports = {
    singleTypes: [
        // get a homepage with a specific entryId
        {
            id: 'homepage',
            directory: 'content',
            fileName: '_index',
            filters: {
                'sys.id': 'my-homepace-id'
            }
        }
    ]
    repeatableTypes: [
        // only get events that start after 01/01/2020
        {
            id: 'events',
            directory: 'content/events',
            filters: {
                'fields.startDate[gte]': '2020-01-01T00:00:00Z',
            },
        },
        // get posts where author is "John Doe" and contains the tag "flowers"
        {
            id: 'posts',
            directory: 'content/posts',
            filters: {
                'fields.author': 'John Doe',
                'fields.tags': 'flowers'
            },
        },
    ];

}

Known Issues

These are some known issues.

• Date & Time Field w/o Timezone: Date fields that include time but do not have a specified timezone will have a timezone set based on whatever machine the script is run on. So using a date field in contentful with this setting could lead to unexpected results when formatting dates. Date fields that don't include time (ex: YYYY-MM-DD) are not effected by this.
• Fetching Data Before Contentful CDN Updates: Sometimes when triggering a build from a webhook, it won't always get the latest data. This is because it sometimes takes a couple seconds for the latest data to get distrubuted across Contentful's CDN. If you run into this issue add teh the --wait flag to your script. Here's an example where we wait an additional 6 seconds contentful-hugo --wait=6000.