This is a Gatsby Remark plugin that provides the same tracking that gatsby-plugin-google-analytics' (or gatsby-plugin-google-gtag)s OutboundLink and trackCustomEvent accomplishes within your actual codebase: the ability to track link clicks to internal & external locations within your markdown. It provides an onClick handler to all links that come from Markdown in your site.

With npm:

npm install --save gatsby-remark-google-analytics-track-links

or with yarn:

yarn add gatsby-remark-google-analytics-track-links

// In gatsby-config.js
plugins: [
  {
    resolve: `gatsby-transformer-remark`,
    options: {
      plugins: [
        //...
        `gatsby-remark-google-analytics-track-links`,
      ],
    },
  },
];

This plugin supports both the (now) legacy window.ga tag, and the newer gtag. If both tags exist on your site, events will be sent to both tags (with the assumption being that most sites will only have one version of the tag).

This plugin adds target="_blank" rel="noopener nofollow noreferrer" properties by default to your external links, as well as a targetable class name ("siteLink" by default). You can opt-out of adding the rel attribute, if desired. Here are all the defaults:

{
  allowFollowLinks: false, //set to true to remove the "rel" attribute entirely
  className: "siteLink",
  localLinkMatch: false, //otherwise should be a string / regex
  gaOptions: {
    internalLinkTitle: "Internal Link", //fallback for internal links if event category not passed
    externalLinkTitle: "External Link", //fallback for external links if event category not passed
    eventCategory: false, //pass a string to customize
    eventAction: `click`,
    eventLabel: false //pass a string to customize
  },
  rel: "noopener nofollow noreferrer", //added to each anchor tag
  runInDev: false, //update to true if your version of GA is available in dev and you want to test tracking
  target: "_blank" // added to each anchor tag
}

You can customize any of the options you would like; the others will be copied from the defaults:

// In gatsby-config.js
plugins: [
  {
    resolve: `gatsby-transformer-remark`,
    options: {
      plugins: [
        //...
        {
          resolve: "gatsby-remark-google-analytics-track-links",
          options: {
            target: "someValue",
            rel: "noopener noreferrer",
            className: "theClassIdLikeInstead",
          },
        },
      ],
    },
  },
];

• allowFollowLinks: removes the rel attribute entirely, allowing you to take advantage of "follow" links
• className: the class added to each anchor tag
• localLinkMatch: string or regex if you need additional matching options for catching internal links; I think most people end up using a combination of gatsby-remark-relative-links and gatsby-plugin-catch-links, but if you needed to catch "absolute-path-y" links in your Markdown that are in fact local links, then this option will let you properly flag the links as internal ones for your GA events
• gaOptions.internalLinkTitle: if you aren't going to use your own custom event category this is the category that will be used for internal links
• gaOptions.externalLinkTitle: same but for external links
• gaOptions.eventCategory: supply this string to override the choices for internal / external link titles
• gaOptions.eventAction: "click" by default, or your own string
• gaOptions.eventLabel: if you don't supply your own string, defaults to event.currentTarget.href; the URL of the link that was clicked, in other words
• rel: defines the relationship from the current page to the linked page. Defaults to noopener nofollow noreferrer for external links; is not added to internal links
• runInDev: by default, this plugin does not run while in Dev mode; this mirrors the settings for gatsby-plugin-google-analytics. If you are installing the GA tag on your own and want to test event sending in development, you can set this flag to true to test. Otherwise, you can test by running gatsby build and then gatsby serve
• target: where to open the link. Defaults to _blank for external links; is not added for internal links

Contributions are welcome, however I would ask that all feature requests come with additional tests added. You are also welcome to contribute in the way of adding tests, though heavy test refactors may be turned away unless there is a pressing need for said refactor. Additionally, I would ask that all PR's be submitted with the default prettier formatting.

Thanks to:

• Gabriel Cutrini for contributing to 0.0.6 by fixing links with inline content!