@draftbox-co/gatsby-plugin-amp

gatsby-plugin-amp

Formats AMP-specific pages by removing javascript, combining styles and adding boilerplate. Read more about AMP (Accelerated Mobile Pages) here.

Install

npm install --save gatsby-plugin-amp

How to use

Create AMP-specific templates. Assume you have the following blog post template in post.js

import React from 'react'
import Img from 'gatsby-image'
import Layout from '../../components/layout'

export default ({ data }) => (
  <Layout>
    <Img fluid={data.image.fluid} />
    <h1>REGULAR PAGE</h1>
    <p>regular page content</p>
  </Layout>
)

Create an AMP template post.amp.js

import React from 'react'
import Layout from '../../components/layout'

export default ({ data }) => (
  <Layout>
    <amp-img src-set={data.image.srcSet} src={data.image.src} width={data.image.width} height={data.image.height} alt={data.image.altText} layout="responsive" />
    <h1>AMP PAGE</h1>
    <p>amp page content</p>
  </Layout>
)

To assist with situations like images in markdown or other externally created HTML, the plugin will attempt to turn img tags to amp-img or amp-anim. While creating posts in your gatsby-node.js file, create an additional page in the /amp/ directory using the AMP template you just made

_.each(posts, (post, index) => {
  const previous = index === posts.length - 1 ? null : posts[index + 1].node;
  const next = index === 0 ? null : posts[index - 1].node;

  createPage({
    path: post.node.fields.slug,
    component: path.resolve('./src/templates/post.js'),
    context: {
      slug: post.node.fields.slug,
      previous,
      next,
    },
  })

  createPage({
    path: `${post.node.fields.slug}/amp`,
    component: path.resolve('./src/templates/post.amp.js'),
    context: {
      slug: post.node.fields.slug,
      previous,
      next,
    },
  })
})

When you build your site, you should now have pages at /my-awesome-post/index.html and /my-awesome-post/amp/index.html

Add the plugin to the plugins array in your gatsby-config.js

{
  resolve: `gatsby-plugin-amp`,
  options: {
    analytics: {
      type: 'gtag',
      dataCredentials: 'include',
      config: {
        vars: {
          gtag_id: <GA_TRACKING_ID>,
          config: {
            <GA_TRACKING_ID>: {
              page_location: '{{pathname}}'
            },
          },
        },
      },
    },
    canonicalBaseUrl: 'http://www.example.com/',
    components: ['amp-form'],
    excludedPaths: ['/404*', '/'],
    pathIdentifier: '/amp/',
    relAmpHtmlPattern: '{{canonicalBaseUrl}}{{pathname}}{{pathIdentifier}}',
    useAmpClientIdApi: true,
  },
},

When your site builds, your page in the /amp directory should now be a valid AMP page

Options

analytics {Object} If you want to include any amp-analytics tags, set that configuration here.

    type {String}     Your analytics type. See the list of available vendors here.

    dataCredentials {String}     You value for the data-credentials attribute. Omit to remove the attribute.

    config {Object | String}     This can be either an object containing your analytics configuration or a url to your analytics configuration. If you use Google Analytics gtag, your cofiguration might look like this:

vars: {
  gtag_id: <GA_TRACKING_ID>,
  config: {
    <GA_TRACKING_ID>: {
      page_location: '{{pathname}}'
    },
  },
},

     If you use a tag manager, your config would simply be a url like https://www.googletagmanager.com/amp.json?id=GTM-1234567&gtm.url=SOURCE_URL. You can use double curly braces to interpolate the pathname into a configuration value e.g. page_location: '{{pathname}}'. See here to learn more about amp-analytics configurations.

canonicalBaseUrl {String} The base URL for your site. This will be used to create a rel="canonical" link in your amp template and rel="amphtml" link in your base page.

components {Array<String | Object{name<String>, version<String>}>} The components you will need for your AMP templates. Read more about the available components here.

excludedPaths{Array<String>} By default, this plugin will create rel="amphtml" links in all pages. If there are pages you would like to not have those links, include them here. You may use glob patterns in your strings (e.g. /admin/*). this may go away if a way can be found to programatically exclude pages based on whether or not they have an AMP equivalent. But for now, this will work

includedPaths{Array<String>} By default, this plugin will create rel="amphtml" links in all pages. If, you would instead like to whitelist pages, include them here. You may use glob patterns in your strings (e.g. /blog/*). this may go away if a way can be found to programatically exclude pages based on whether or not they have an AMP equivalent. But for now, this will work

pathIdentifier {String} The url segment which identifies AMP pages. If your regular page is at http://www.example.com/blog/my-awesome-post and your AMP page is at http://www.example.com/blog/my-awesome-post/amp/, your pathIdentifier should be /amp/

relAmpHtmlPattern {String} The url pattern for your rel="amphtml" links. If your AMP pages follow the pattern http://www.example.com/my-awesome-post/amp/, the value for this should be {{canonicalBaseUrl}}{{pathname}}{{pathIdentifier}}.

relCanonicalPattern {String} The url pattern for your rel="canonical" links. The default value is {{canonicalBaseUrl}}{{pathname}}.

useAmpClientIdApi {Boolean} If you are using a Client ID for Google Analytics, you can use the Google AMP Client ID to determine if events belong to the same user when they visit your site on AMP and non-AMP pages. Set this to true if you would like to include the necessary meta tag in your AMP pages. You can read more about this concept here

Caveats

The standard HTML template that Gatsby uses will cause a validation error. This is because it is missing minimum-scale=1 in the meta viewport tag. You can create a html.js template file under your src/ directory in order to override the default Gatsby one available here. Alternatively, you can simply clone it by runnig the shell command below at the root of your project. Read more here on customizing your html.js.

cp .cache/default-html.js src/html.js

Don't forget to update the meta viewport tag value from its initial to the required AMP value.

<!-- Initial viewport meta tag -->
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
<!-- Replacement viewport meta tag (for AMP validity) -->
<meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, shrink-to-fit=no" />

Automatically Converted Elements

While it is preferable to create AMP-specific templates, there may be situations where an image, iframe or some other element can't be modified. To cover these cases, the plugin will attempt to convert certain tags to their AMP equivalent.

HTML Tag	AMP Tag	Status	Issue
img	amp-img	Completed
img (.gif)	amp-anim	Completed
iframe	amp-iframe	Completed
audio	amp-audio	Planned, Not Started
video	amp-video	Planned, Not Started
YouTube	amp-youtube	Completed
Facebook	amp-facebook	Planned, Not Started
Instagram	amp-instagram	Planned, Not Started
Twitter	amp-twitter	Completed