Angular 4+ using Google Analytics
I'm trying to use the Google Analytics with angular 4, but i can't find any @type to ga.js in ts.
For a quick solution I used this in every component:
declare let ga: any;
Following how I resolved it:
Create a function to load the GA dynamically that inserts the GA script with current trackingId and user.
loadGA(userId) {
if (!environment.GAtrackingId) return;
let scriptId = 'google-analytics';
if (document.getElementById(scriptId)) {
return;
}
var s = document.createElement('script') as any;
s.type = "text/javascript";
s.id = scriptId;
s.innerText = "(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)})(window,document,'script','//www.google-analytics.com/analytics.js','ga');ga('create', { trackingId: '" + **environment.GAtrackingId** + "', cookieDomain: 'auto', userId: '" + **userId** + "'});ga('send', 'pageview', '/');";
document.getElementsByTagName("head")[0].appendChild(s);
}
Create the service to implement the methods that you will need.
import { Injectable } from '@angular/core';
import { environment } from '../../../environments/environment';
declare let ga: any;
@Injectable()
export class GAService {
constructor() {
}
/**
* Checks if the GA script was loaded.
*/
private useGA() : boolean {
return environment.GAtrackingId && typeof ga !== undefined;
}
/**
* Sends the page view to GA.
* @param {string} page The path portion of a URL. This value should start with a slash (/) character.
*/
sendPageView(
page: string
) {
if (!this.useGA()) return;
if (!page.startsWith('/')) page = `/${page}`;
ga('send', 'pageview', page);
}
/**
* Sends the event to GA.
* @param {string} eventCategory Typically the object that was interacted with (e.g. 'Video')
* @param {string} eventAction The type of interaction (e.g. 'play')
*/
sendEvent(
eventCategory: string,
eventAction: string
) {
if (!this.useGA()) return;
ga('send', 'event', eventCategory, eventAction);
}
}
Then I finally use the service injected in component.
constructor(private ga: GAService) {}
ngOnInit() { this.ga.sendPageView('/join'); }
Answer
First of all, you need to install typings for Google Analytics in your devDependencies
npm install --save-dev @types/google.analytics
Then add your tracking code in the base index.html, and remove the last line as shown bellow:
<body>
<app-root>Loading...</app-root>
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-XXXXXX-ID', 'auto'); // <- add the UA-ID
// <- remove the last line
</script>
</body>
The next step consists to update your home component constructor for event tracking.
constructor(public router: Router) {
this.router.events.subscribe(event => {
if (event instanceof NavigationEnd) {
ga('set', 'page', event.urlAfterRedirects);
ga('send', 'pageview');
}
});
}
If you want to track some specific event, you can also create a service and inject it into any component that you want to implement event tracking.
// ./src/app/services/google-analytics-events-service.ts
import {Injectable} from "@angular/core";
@Injectable()
export class GoogleAnalyticsEventsService {
public emitEvent(eventCategory: string,
eventAction: string,
eventLabel: string = null,
eventValue: number = null) {
ga('send', 'event', { eventCategory, eventLabel, eventAction, eventValue });
}
}
So if you want track a click on your home component for example, all you need to do is to inject the GoogleAnalyticsEventsService and call the emitEvent() method.
The updated home component source code:
constructor(public router: Router, public googleAnalyticsEventsService: GoogleAnalyticsEventsService) {
this.router.events.subscribe(event => {
if (event instanceof NavigationEnd) {
ga('set', 'page', event.urlAfterRedirects);
ga('send', 'pageview');
}
});
}
submitEvent() { // event fired from home.component.html element (button, link, ... )
this.googleAnalyticsEventsService.emitEvent("testCategory", "testAction", "testLabel", 10);
}