allow exclusion of paths

README.md

@@ -57,11 +57,31 @@ Option           | Explanation
 `siteId`         | Your Matomo site ID configured in your Matomo installation.
 `matomoUrl`      | The url of your Matomo installation.
 `siteUrl`        | The url of your site, usually the same as `siteMetadata.siteUrl`. Only used for generating the url for `noscript` image tracking fallback.
+`exclude`        | (optional) Specify an array of pathnames where tracking code will be excluded. The pathname `/offline-plugin-app-shell-fallback/` is excluded by default.
 `requireConsent` | (optional) If true, tracking will be disabled until you call `window._paq.push(['setConsentGiven']);`.
 `disableCookies` | (optional) If true, no cookie will be used by Matomo.
-`localScript`    | (optional) Set path to load local `piwik.js` script, instead of loading it from your `matomoUrl`.
+`localScript`    | (optional) If set, load local `piwik.js` script from the given path, instead of loading it from your `matomoUrl`.
 `dev`            | (optional) Activate dev mode by setting to `true`. Will load all scripts despite not running in `production` environment. Ignores your local browser's DNT header too. Outputs some information in console about what it is doing. Useful for local testing but careful: all hits will be send like in production.
 
+```js
+plugins: [
+  {
+    resolve: 'gatsby-plugin-matomo',
+    options: {
+      siteId: 'YOUR_SITE_ID',
+      matomoUrl: 'https://YOUR_MATOMO_URL.COM',
+      siteUrl: 'https://YOUR_LIVE_SITE_URL.COM'
+      // All the optional settings
+      exclude: ['/offline-plugin-app-shell-fallback/'],
+      requireConsent: false,
+      disableCookies: false,
+      localScript: '/piwik.js',
+      dev: false
+    }
+  }
+]
+```
+
 ## Development
 
 ```bash

src/gatsby-ssr.js

@@ -7,7 +7,7 @@ function buildTrackingCode(pluginOptions) {
 
   const html = `
     window.dev = ${pluginOptions.dev}
-    if (window.dev === true || !(navigator.doNotTrack == '1' || window.doNotTrack == '1')) {
+    if (window.dev === true || !(navigator.doNotTrack === '1' || window.doNotTrack === '1')) {
       window._paq = window._paq || [];
       ${pluginOptions.requireConsent ? 'window._paq.push([\'requireConsent\']);' : ''}
       ${pluginOptions.disableCookies ? 'window._paq.push([\'disableCookies\']);' : ''}
@@ -50,7 +50,20 @@ function buildTrackingCodeNoJs(pluginOptions, pathname) {
 }
 
 exports.onRenderBody = ({ setPostBodyComponents, pathname }, pluginOptions) => {
-  if (process.env.NODE_ENV === 'production' || pluginOptions.dev === true) {
+  let excludePaths = ['/offline-plugin-app-shell-fallback/']
+
+  if (typeof pluginOptions.exclude !== 'undefined') {
+    pluginOptions.exclude.map(exclude => {
+      excludePaths.push(exclude)
+    })
+  }
+
+  const isPathExcluded = excludePaths.some(path => pathname === path)
+
+  if (
+    (process.env.NODE_ENV === 'production' || pluginOptions.dev === true) &&
+    !isPathExcluded
+  ) {
       return setPostBodyComponents([
         buildTrackingCode(pluginOptions),
         buildTrackingCodeNoJs(pluginOptions, pathname)