gatsby-source-wpgraphql-images

Important

This is a still early version of the plugin, your mileage may vary!

Description

This plugin is a variant of gatsby-plugin-graphql-image and gatsby-wpgraphql-inline-images. It is a source plugin that will download all media items from wordpress (warning this can take a long time) and attempts to aggressively cache these for future rebuilds.

The problem with the above mentioned plugins is that they will cause frequent rebuilds of the whole page tree which (depending on your wordpress instance) can take a significant amount of time. For more information about this problem, see

In addition these plugins dont aggressively cache the wordpress media files and on every rebuild it will cause a HTTP HEAD request for every media item therefore, additionally increasing the build times.

  • Downloads images and other files to Gatsby static folder
  • Replaces <a> linking to site’s pages with <Link> component
  • Replaces <img> with Gatsby <Img> component leveraging all of the gatsby-image rich functionality

Dependencies

This plugin processes WordPress content sourced with GraphQL. Therefore you must use gatsby-source-graphql and your source WordPress site must use WPGraphQL.

Attention: does not work with gatsby-source-wordpress.

How to install

yarn add gatsby-source-wpgraphql-images
{
  resolve: 'gatsby-source-wpgraphql-images',
  options: {
    wordPressUrl: 'https://mydomain.com/',
    uploadsUrl: 'https://mydomain.com/wp-content/uploads/',
    processPostTypes: ['Page', 'Post', 'CustomPost'],
    graphqlTypeName: 'WPGraphQL',
    httpHeaders: {
      Authorization: `Bearer ${process.env.GITHUB_TOKEN}`,
    }
  },
},

Available options

wordPressUrl and uploadsUrl contain URLs of the source WordPress site and it’s uploads folder respectively.

processPostTypes determines which post types to process. You can include custom post types as defined in WPGraphQL.

customTypeRegistrations allows additional registration of parsed html content for arbitrary graphql types. For more information, see examples below.

keyExtractor a function that extracts the cache key for a specific node, typically this is the uri of a post.

graphqlTypeName should contain the same typeName used in gatsby-source-graphql parameters.

generateWebp (boolean) adds WebP images.

httpHeaders Adds extra http headers to download request if passed in.

debugOutput (boolean) Outputs extra debug messages.

shouldDownloadMediaItem a function that takes an URL of a media file and decides whether it should be downloaded or not. Allows more complex configuration.

supportedExtensions a map in the form of

cacheTimeInSeconds the time how long we will cache the parsed output, this is specifically important to configure in case you are using the refetchInterval for gatsby-source-graphql. Otherwise parsed values will be cached for the lifetime of the gatsby develop run. If this value is not set, then values will be cached indefinitely even if the underlying data changes.

{ pdf: true, mp3: true, jpg: true, jpeg: true, png: true }

that determines which types of media files should be downloaded. Note that this check is done before shouldDownloadMediaItem is called

How to use this plugin

Downloading and optimizing images is done automatically via resolvers. You need to include uri in all queries that will be processed by the plugin otherwise they will be ignored. In addition this plugin will also add custom resolvers for the specified graphql types with the format

For instance, lets assume we have content on the type WPGraphQL, then you need to additionally query contentParsed and contentFiles. The resolver will parse the content, prepare inline img and a tags and look for previously downloaded media files for this url.

query GET_PAGES {
  wpgraphql {
    pages {
      nodes {
        uri
        content
        contentParsed
        contentFiles {
          publicURL
          childImageSharp {
            fluid(maxWidth: 720) {
              ...GatsbyImageSharpFluid_withWebp
              presentationWidth
            }
          }
        }
      }
    }
  }
}

There is an additional step of processing content that must be added manually to a page template. This additional processing replaces remote urls with links to downloaded files in Gatsby’s static folder.

import contentParser from 'gatsby-source-wpgraphql-images'

replace <div dangerouslySetInnerHTML={{ __html: content }} /> with this

<div>{contentParser({ content: contentParsed, files: contentFiles }, { wordPressUrl, uploadsUrl })}</div>

Where content is the original HTML content and URLs should use the same values as in the options above. contenParser returns React object.

The recommended handling of featuredImage and WordPress media in general is described by henrikwirth in this article and this gist.

WordPress galleries

WordPress galleries may need some additional styling applied and this was intentionally left out of the scope of this plugin. Emotion Global Styles may be used or just import sass/css file.

.gallery {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
}
.gallery-item {
  margin-right: 10px;
}

Gatsby themes support

Inserted <Img> components have variant: 'styles.SourcedImage' applied to them.

Examples of usage

I’m going to use gatsby-wpgraphql-blog-example as a starter and it will source data from a demo site at yourdomain.dev.

Add this plugin to the gatsby-config.js

{
  resolve: 'gatsby-source-wpgraphql-images',
  options: {
    wordPressUrl: `https://yourdomain.dev/`,
    uploadsUrl: `https://yourdomain.dev/wp-content/uploads/`,
    processPostTypes: ["Page", "Post"],
    graphqlTypeName: 'WPGraphQL',
  },
},

Change url in gatsby-source-graphql options to https://yourdomain.dev/graphql

Page templates are stored in src/templates. Let’s modify post.js as an example.

Importing contentParser

import contentParser from 'gatsby-source-wpgraphql-images'

For simplicty’s sake I’m just going to add URLs directly in the template.

const pluginOptions = {
  wordPressUrl: `https://yourdomain.dev/`,
  uploadsUrl: `https://yourdomain.dev/wp-content/uploads/`,
}

and replace dangerouslySetInnerHTML with this

<div>{contentParser({ content, files }, pluginOptions)}</div>

The modified example starter is available at github.com/progital/gatsby-wpgraphql-blog-example.

Examples of advanced usage

Add this plugin to the gatsby-config.js

{
  resolve: 'gatsby-source-wpgraphql-images',
  options: {
    wordPressUrl: `https://yourdomain.dev/`,
    uploadsUrl: `https://yourdomain.dev/wp-content/uploads/`,
    graphqlTypeName: 'WPGraphQL',
    customTypeRegistrations: [
      {
        graphqlTypeName: "WPGraphQL_Page_Acfdemofields",
        fieldName: "fieldInAcf",
      },
    ],
    keyExtractor: (source, context, info) => source.uri || source.key,
  },
},

This example assumes that there is a GraphQL type WPGraphQL_Page_Acfdemofields that has a field fieldInAcf, e.g.

query MyQuery {
  wpgraphql {
    pages {
      nodes {
        acfDemoFields {
          fieldInAcf
          fieldInAcfParsed
          fieldInAcfFiles {
            publicURL
            childImageSharp {
              fluid(maxWidth: 720) {
                ...GatsbyImageSharpFluid_withWebp
                presentationWidth
              }
            }
          }
        }
      }
    }
  }
}

How to contribute

This is a WIP and any contribution, feedback and PRs are very welcome.