gatsby-plugin-guess-js

Gatsby plugin for integrating Guess.js with Gatsby.

Guess.js is a library for enabling data-driven user-experiences on the web.

When this plugin is added to your site, it will automatically download Google Analytics data and use this to create a model to predict which page a user is most likely to visit from a given page.

The plugin uses this information to do two things.

• When generating HTML pages, it automatically adds <link prefetch> for resources on pages the user is likely to visit. This means that as soon as a person visits your site, their browser will immediately start downloading in the background code and data for links they’ll likely click on which can dramatically improve the site performance.
• Once the person has loaded your site and visits additional pages, the plugin will continue to predict which pages will be visited and prefetch their resources as well.

Demo

https://guess-gatsby-wikipedia-demo.firebaseapp.com

Install

npm install gatsby-plugin-guess-js

How to use

// In your gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: "gatsby-plugin-guess-js",
      options: {
        // Find the view id in the GA admin in a section labeled "views"
        GAViewID: `VIEW_ID`,
        // Add a JWT to get data from GA
        jwt: {
          client_email: `GOOGLE_SERVICE_ACCOUNT_EMAIL`,
          private_key: `GOOGLE_SERVICE_ACCOUNT_PRIVATE_KEY`,
        },
        minimumThreshold: 0.03,
        // The "period" for fetching analytic data.
        period: {
          startDate: new Date("2018-1-1"),
          endDate: new Date(),
        },
      },
    },
  ],
}

Integrating with CI

Integrating this plugin within a CI pipeline may cause errors because the plugin will prompt the user/machine to log into the Google Analytics account. To get around this you’ll need to generate a JWT for your GA account to pass to the plugin, this will enable the plugin to work in prod without any human interaction to authenticate permissions

// In your gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: "gatsby-plugin-guess-js",
      options: {
        // Find the view id in the GA admin in a section labeled "views"
        GAViewID: `VIEW_ID`,
        minimumThreshold: 0.03,
        // Set Google Analytics jwt with Google Service Account email and private key
        jwt: {
          client_email: `GOOGLE_SERVICE_ACCOUNT_EMAIL`,
          private_key: `GOOGLE_SERVICE_ACCOUNT_PRIVATE_KEY`,
        },
        // The "period" for fetching analytic data.
        period: {
          startDate: new Date("2018-1-1"),
          endDate: new Date(),
        },
      },
    },
  ],
}

How to get a JWT token?

Excerpt from https://developers.google.com/identity/protocols/oauth2/service-account

1. Open the Google Developer Console IAM & Admin
2. If prompted, select a project, or create a new one.
3. Click add service account.
4. on top click Create service account, type a name, ID, and description for the service account, then click Create.
5. Optional: Under Service account permissions, select the IAM roles to grant to the service account, then click Continue.
6. Optional: Under Grant users access to this service account, add the users or groups that are allowed to use and manage the service account.
7. Click on three dots under actions , then click Create.

• Put that file into a directory node_modules that is inside one of the parent directories of the script that we’ll create later. That means that you can keep it out of the repository with analytics.js. For example, the following path is perfectly fine: \$HOME/node_modules/myproject-3126e4caac6a.json
  • The credentials that you created have an client_email address (which is displayed in the user interface and stored inside the JSON file). Copy that email address.

Go to the Admin panel in Google Analytics:

• Analytics has three scopes:
  • Account
  • Property
  • View
• Create a new user in scope “Property”, via “Admin -> View User Management -> Plus icon -> Add User”.
  • That user has the email address that you copied previously from the json file client_email.
  • Its permissions are “Read & Analyze”.
• In scope “View”, go to “View Settings” and write down the “View ID” (e.g. 97675673) for later.

Note: This JWT will only be valid for a finite amount of time. If you would like to generate a token that will not expire, please follow further instructions in https://2ality.com/2015/10/google-analytics-api.html

Troubleshooting

• “User does not have any Google Analytics Account”: StackOverflow answer