gridsome-plugin-image-cdn

A plugin to help you use an image CDN with Gridsome.

This plugin enables you to add an image CDN to your site (e.g. ImageKit, Cloudinary, Sirv) and easily set the available transform parameters in your GraphQL query. For example, using ImageKit (and @gridsome/source-graphql):

{
  WordPress {
    posts {
      nodes {
        id
        title
        featuredImage {
          sourceUrl(
            width: 600
            height: 400
            crop: MAINTAIN,
            cropMode: RESIZE,
            quality: 85
            format: AUTO
          ) # https://ik.imagekit.io/my-account/named-endpoint/tr:w-600,h-400,q-85,c-maintain_ratio,cm-resize,f-auto/path/to/some/image.jpg
        }
      }
    }
  }
}

Install

yarn add gridsome-plugin-image-cdn # or
npm install gridsome-plugin-image-cdn

Usage

gridsome.config.js

module.exports = {
  plugins: [
    {
      use: 'gridsome-plugin-image-cdn',
      options: {
        site: {
          baseUrl: '<URL of your site>'
        },
        cdn: {
          baseUrl: '<URL of the configured CDN>',
          preset: 'imageKit', # optional, but a custom transformer is required if not included
          imagePrefix: '/<some prefix>', # optional
        },
        types: [
          {
            typeName: '<some media type>',
            sourceField: '<image URL field>'
          }
        ]
      }
    }
  ]
}

Configuration & Presets

This intends to be a one-size-fits-all plugin, so there are a few configurable options. It also comes with a few built-in presets for some popular image CDN providers.

Key	Options	Explanantion
site	baseUrl	The base URL of the site the images are being pulled from. This will be replaced by the CDN url configured below.
cdn	baseUrl	The URL of the CDN you are using.
cdn	preset	You can use one of the preconfigured presets below.
cdn	imagePrefix	This will be added to the image path, after the CDN URL and transformations, and before the image path (/path/to/image.jpg)
types	typeName	The name of the GraphQL type which contains the image URL - you can find this in the GraphQL playground Schema/Docs tab.
types	sourceField	The field in the above type which contains the image URL.

Presets

This plugin supports three main CDN providers out of the box - ImageKit, Cloudinary, Sirv. All of these allow remote file support, so you can use them in front of a headless WordPress site, or S3 bucket for example.

imageKit

Options	Explanantion	Example
baseUrl	The base URL/image URL endpoint from your configured ImageKit source.	https://ik.imagekit.io/<ImageKit ID>/<ImageKit Endpoint Identifier>
preset	imageKit
imagePrefix	Not needed for ImageKit.

cloudinary

Options	Explanantion	Example
baseUrl	The base URL of your Cloudinary account - this will be shown as 'Secure delivery URL:' in your account dashboard.	https://res.cloudinary.com/<your account>
preset	cloudinary
imagePrefix	If pulling from a remote source, and your images go into a folder, you will probably need to add that prefix here (make sure to include a leading slash).	/some-folder

sirv

Options	Explanantion	Example
baseUrl	The base URL of your Sirv account (including subdomain) or the domain of your custom endpoint.	https://<account subdomain>.sirv.com
preset	sirv
imagePrefix	If your images are organised into folders, for example when using the Wordpress plugin, you may need to add this prefix.	/WP_some_site

Examples

These examples assume a setup using the Gridsome Source GraphQL plugin, and WordPress with WPGraphQL.

imageKit

{
  use: '@gridsome/source-graphql',
  options: {
    url: 'https://demo.wpgraphql.com/graphql',
    fieldName: 'WordPress',
    typeName: 'wordPress'
  }
},
{
  use: 'gridsome-plugin-image-cdn',
  options: {
    site: {
      baseUrl: 'https://demo.wpgraphql.com'
    },
    cdn: {
      baseUrl: 'https://ik.imagekit.io/travis/wordpress',
      preset: 'imageKit'
    },
    types: [
      {
        typeName: 'wordPress_MediaItem',
        sourceField: 'sourceUrl'
      }
    ]
  }
}

<template>
  <Layout>
    <div class="section">
      <h1>{{ this.$page.WordPress.post.title }}
      <img :src="this.$page.WordPress.post.featuredImage.sourceUrl" :alt="this.$page.WordPress.post.featuredImage.altText" />
    </div>
  </Layout>
</template>

<page-query>
query {
  WordPress {
    post (id: "cG9zdDoxMDEx") {
      id
      title
      featuredImage {
        altText
        sourceUrl(
          width: 600
          height: 400
          crop: MAINTAIN,
          cropMode: RESIZE,
          quality: 85
          format: AUTO
        ) # https://ik.imagekit.io/travis/wordpress/tr:w-600,h-400,q-85,c-maintain_ratio,cm-resize,f-auto/wp-content/uploads/2013/03/featured-image-horizontal.jpg
      }
    }
  }
}
</page-query>

cloudinary

{
  use: '@gridsome/source-graphql',
  options: {
    url: 'https://demo.wpgraphql.com/graphql',
    fieldName: 'WordPress',
    typeName: 'wordPress'
  }
},
{
  use: 'gridsome-plugin-image-cdn',
  options: {
    site: {
      baseUrl: 'https://demo.wpgraphql.com'
    },
    cdn: {
      baseUrl: 'https://res.cloudinary.com/travis',
      preset: 'cloudinary',
      imagePrefix: '/wp-graphql'
    },
    types: [
      {
        typeName: 'wordPress_MediaItem',
        sourceField: 'sourceUrl'
      }
    ]
  }
}

{
  WordPress {
    post (id: "cG9zdDoxMDEx") {
      id
      title
      cover: featuredImage {
        altText
        sourceUrl(
          width: 600
          height: 400
          crop: CROP,
          quality: "auto"
        ) # https://res.cloudinary.com/travis/w_600,h_400,c_crop,q_auto/wp-graphql/wp-content/uploads/2013/03/featured-image-horizontal.jpg
      }
    }
  }
}

Lazy Load

You could easily use this plugin with some Vue lazy load plugins, by making use of GraphQL aliases - for example, with v-lazy-image (using imageKit):

<template>
  <Layout>
    <div class="section">
      <h1>{{ this.$page.WordPress.post.title }}
      <v-lazy-image
        :src="this.$page.WordPress.post.featuredImage.sourceUrl"
        :src-placeholder="this.$page.WordPress.post.featuredImage.placeholder"
        :alt="this.$page.WordPress.post.featuredImage.altText" />
    </div>
  </Layout>
</template>

<script>
import VLazyImage from 'v-lazy-image'
export default {
  components: {
    VLazyImage
  }
}
</script>

<page-query>
query {
  WordPress {
    post (id: "cG9zdDoxMDEx") {
      id
      title
      featuredImage {
        altText
        sourceUrl(
          width: 800
          height: 600
          crop: MAINTAIN,
          cropMode: RESIZE,
          quality: 85
          format: AUTO
        )
        placeholder: sourceUrl(
          width: 200
          height: 100
          crop: MAINTAIN,
          cropMode: RESIZE,
          quality: 40
          blur: 20
          format: AUTO
        )
      }
    }
  }
}
</page-query>

Custom Transformer

This plugin uses a transformer function to convert query arguments into query parameters a CDN uses. You can add a custom transformer (along with custom query arguments) by using the transformer option in gridsome.config.js. Below is an explanation of what this option needs:

The transformer option takes in a object, containing three functions - createSchemaTypes, createResolverArgs, and transformer.

createSchemaTypes

createSchemaTypes will receive a single argument - schema. Use this to add any custom Enums your arguments may use. For example:

...
createSchemaTypes: schema => [
  schema.createEnumType({
    name: 'ImageCDNCrop',
    values: {
      MAINTAIN: {
        value: 'maintain_ratio'
      },
      FORCE: {
        value: 'force'
      },
      ...
    }
  })
],
...

createResolverArgs

createResolverArgs has no arguments, and should simply return an object, containing all image arguments (parameters):

...
createResolverArgs: () => ({
  width: 'Int',
  height: 'Int',
  quality: 'Int',
  crop: 'ImageCDNCrop' // The custom Enum we created above
})
...

transformer

transformer will receive an object containing three keys - cdn (from config options), sourceUrl (the bare image URL), and args (the arguments from the current query), and should return a string. These arguments can all be used to generate a transform url, for example:

...
transformer: ({ cdn, sourceUrl, args }) => {
  // Create a map of all available transforms, and their prefixes
  const transformArgs = new Map([
    ['height', { prefix: 'h' }],
    ['width', { prefix: 'w' }],
    ['quality', { prefix: 'q' }],
    ['crop', { prefix: 'c' }]
  ])

  // Create an empty array we can push transformations to
  const transformations = []

  // Loop through each argument, and set the respective transform
  for (const [key, value] of Object.entries(args)) {
    // Get the prefix for a transform, and add that and the value to the transform array
    const { prefix } = transformArgs.get(key)
    transformations.push(`${prefix}-${value}`) // e.g. 'w-400', 'q-85'
  }

  // Concat and return all our joined transforms
  const transformUrl = transformations.length ? `/${transformations.join(',')}` : '' // e.g. /w-400,q-85
  return `${cdn.baseUrl}${transformUrl}${sourceUrl}`
},
...