gatsby-source-contentful

Source plugin for pulling content types, entries, and assets into Gatsby from Contentful spaces. It creates links between entry types and asset so they can be queried in Gatsby using GraphQL.

An example site for using this plugin is at https://using-contentful.gatsbyjs.org/

Install

npm install --save gatsby-source-contentful

How to use

First, you need a way to pass environment variables to the build process, so secrets and other secured data aren't committed to source control. We recommend using dotenv which will then expose environment variables. Read more about dotenv and using environment variables here. Then we can use these environment variables and configure our plugin.

Using Delivery API

// In your gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-source-contentful`,
      options: {
        spaceId: `your_space_id`,
        // Learn about environment variables: https://gatsby.app/env-vars
        accessToken: process.env.CONTENTFUL_ACCESS_TOKEN,
      },
    },
  ],
}

Using Preview API

// In your gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-source-contentful`,
      options: {
        spaceId: `your_space_id`,
        // Learn about environment variables: https://gatsby.app/env-vars
        accessToken: process.env.CONTENTFUL_ACCESS_TOKEN,
        host: `preview.contentful.com`,
      },
    },
  ],
}

Offline

If you don't have internet connection you can add export GATSBY_CONTENTFUL_OFFLINE=true to tell the plugin to fallback to the cached data, if there is any.

Configuration options

spaceId [string][required]

Contentful spaceId

accessToken [string][required]

Contentful delivery api key, when using the Preview API use your Preview API key

host [string][optional] [default: 'cdn.contentful.com']

The base host for all the API requests, by default it's 'cdn.contentful.com', if you want to use the Preview API set it to 'preview.contentful.com'. You can use your own host for debugging/testing purposes as long as you respect the same Contentful JSON structure.

environment [string][optional] [default: 'master']

The environment to pull the content from, for more info on environments check out this Guide.

You can pass in any other options available in the contentful.js SDK.

Notes on Contentful Content Models

There are currently some things to keep in mind when building your content models at Contentful.

1. At the moment, fields that do not have at least one populated instance will not be created in the GraphQL schema.

2. When using reference fields, be aware that this source plugin will automatically create the reverse reference. You do not need to create references on both content types. For simplicity, it is easier to put the reference field on the child in child/parent relationships.

How to query for nodes

Two standard node types are available from Contentful: Asset and ContentType.

Asset nodes will be created in your site's GraphQL schema under contentfulAsset and allContentfulAsset.

ContentType nodes are a little different - their exact name depends on what you called them in your Contentful data models. The nodes will be created in your site's GraphQL schema under contentful${entryTypeName} and allContentful${entryTypeName}.

In all cases querying for nodes like contentfulX will return a single node, and nodes like allContentfulX will return all nodes of that type.

Query for all nodes

You might query for all of a type of node:

{
  allContentfulAsset {
    edges {
      node {
        id
        file {
          url
        }
      }
    }
  }
}

You might do this in your gatsby-node.js using Gatsby's createPages Node API.

Query for a single node

To query for a single image asset with the title 'foo' and a width of 1600px:

export const assetQuery = graphql`
  {
    contentfulAsset(filter: { title: { eq: 'foo' } }) {
      image {
        resolutions(width: 1600) {
          width
          height
          src
          srcSet
        }
      }
    }
  }
`

To query for a single CaseStudy node with the short text properties title and subtitle:

  {
    contentfulCaseStudy(filter: { title: { eq: 'bar' } })  {
      title
      subtitle
    }
  }

Note the use of GraphQL arguments on the contentfulAsset and resolutions fields. See Gatsby's GraphQL reference docs for more info.

You might query for a single node inside a component in your src/components folder, using Gatsby's StaticQuery component.

A note about LongText fields

If you include fields with a LongText type in your Contentful ContentType, their returned value will be an object not a string. This is because Contentful LongText fields are Markdown by default. In order to handle the Markdown content properly, this field type is created as a child node so Gatsby can transform it to HTML.

ShortText type fields will be returned as strings.

Querying a single CaseStudy node with the ShortText properties title and subtitle and LongText property body requires formatting the LongText fields as an object with the child node containing the exact same field name as the parent:

{
  contentfulCaseStudy {
    title
    subtitle
    body {
      body
    }
  }
}

Duplicated entries

When Contentful pulls the data, all localizations will be pulled. Therefore, if you have a localization active, it will duplicate the entries. Narrow the search by filtering the query with node_locale filter:

{
  allContentfulCaseStudy(filter: { node_locale: { eq: "en-US" } }) {
    edges {
      node {
        id
        slug
        title
        subtitle
        body {
          body
        }
      }
    }
  }
}

Query for Assets in ContentType nodes

More typically your Asset nodes will be mixed inside of your ContentType nodes, so you'll query them together. All the same formatting rules for Asset and ContentType nodes apply.

To get all the CaseStudy nodes with ShortText fields id, slug, title, subtitle, LongText field body and heroImage Asset field, we use allContentful${entryTypeName} to return all instances of that ContentType:

{
  allContentfulCaseStudy {
    edges {
      node {
        id
        slug
        title
        subtitle
        body {
          body
        }
        heroImage {
          resolutions(width: 1600) {
            width
            height
            src
            srcSet
          }
        }
      }
    }
  }
}

More on Queries with Contentful and Gatsby

It is strongly recommended that you take a look at how data flows in a real Contentful and Gatsby application to fully understand how the queries, Node.js functions and React components all come together. Check out the example site at using-contentful.gatsbyjs.org.

Beta Contentful Rich Text

Rich text feature is supported in this source plugin, if you want to serialize the field content to html you can add the plugin @contentful/gatsby-transformer-contentful-richtext.

After adding the transformer plugin you can use the following query to get the html output:

{
  allContentfulBlogPost {
    bodyRichText {
      childContentfulRichText {
        html
      }
    }
  }
}