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Friday, October 2, 2020 7:39 PM

Add Google Analytics To A Nuxt Js App

Let me show you how to add Google Analytics to your Nuxt JS app, whilst ensuring that you comply with GDPR legislation with a cookie banner.

Analytics
Add Google Analytics To A Nuxt Js App

Over recent weeks, I've been working hard to make this blog look and work well. Now that I'm writing more often, I wanted a way to see what's working and what's not. My first thought was to add Google Analytics as I remember it being a quick and easy process.

That said, the days when you could just add analytics without thinking about the privacy of your users is thankfully coming to an end. As it turns out, some more work is needed to comply with GDPR and other legislation. In this article, I'll show you how I went about adding Google Analytics and a compliant Cookie Banner to this site.

If you've installed Google Analytics on a website in the past, you might be familiar with the analytics.js script. Google has now moved away from this script in favour of its gtag.js or Global Site Tag solution. They strongly recommend that we should upgrade to the new "modern measurement library" and so we'll do just that.

Install GTAG on a simple HTML website

If you're looking to install gtag on a simple HTML website, you can simpy follow Google's instructions to paste the following code immediately after the <head> tag on every page of your site, making sure to replace GA_MEASUREMENT_ID with the Google Analytics property that you want to send the data to.

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=GA_MEASUREMENT_ID"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'GA_MEASUREMENT_ID');
</script>

If you're using a templating engine, you can paste the code in of your layout file, so that it is loaded automatically on every page that uses that layout.

Installing GTAG in a Nuxt JS app

Nuxt allows you to customise the app html template by creating an app.html file in the src directory of your project. We could easily place the gtag.js script there, but we can do better than that by pulling in a small npm package that wraps the gtag script. I've chosen to use vue-gtag, but you could use the same technique with another package if you prefer.

  1. Install vue-gtag in your application:
npm install vue-gtag
  1. Create a new javascript file in the plugins directory and load the vue-gtag plugin, making sure to replace the following properties with your own:
  • GA_MEASUREMENT_ID - the ID of the property to which you want to send data.
  • APP_NAME - The name of your application.
import Vue from 'vue';
import VueGtag from 'vue-gtag';

Vue.use(VueGtag, {
    config: { id: 'GA_MEASUREMENT_ID' },
    appName: 'APP_NAME',
});
  1. Tell Nuxt to load your Google Analytics plugin.
plugins: [
    {
        src: './plugins/GoogleAnalytics.js',
        mode: 'client'
    }
]

At this point, the gtag.js script should load on all pages and environments in your app, but you really shouldn't stop here. Read on to find out how to make sure you only load the script once you have obtained the consent of your users.

GDPR, PECR and EU cookie compliance

When you install gtag.js, Google will place cookies in the user's browser to track the user uniquely. There are three things we need to do to make sure that we comply with PECT, GDPR, and other similar regulations as well as Google's own terms. Let's discuss each of these in turn.

  1. Tell visitors to our site that we are using cookies.

The convention is to add a banner to inform users that the site uses cookies. The banner should load immediately when the user first visits the site.

Cookie Banner Cookie Banner

  1. Explain what the cookies are doing and why.

The cookie banner should have a link to a clear explanation describing the cookies that will be used as well as their purpose. This will help the user to make an informed decision.

Privacy Policy Privacy Policy

  1. Get the user's consent before placing cookies on their device.

The banner should be displayed until the user specifies whether they accept the use of cookies. If they click yes, we can go ahead and load the analytics plugin which will store cookies on their device. If they click no, we will prevent the analytics tracker from loading. In both cases, we will remove the banner once the user has made their choice.

Now we know what needs to be done, we can make a CookieAlert vue component to add the banner to our site. I'm using Tailwind CSS for styling, but you can change the template to suit your needs.

First, we will define the way the banner should look in the template tag of our component:

    <div v-if="isOpen"
         class="fixed bottom-0 left-0 lg:flex items-center p-4 bg-gray-100 shadow-sm justify-center w-full">
        <div class="text-5xl pb-2 leading-none">
            🍪
        </div>
        <div class="lg:mx-8">
            <p>
                Can I use cookies for analytics? Read
                <nuxt-link class="text-link" to="/privacy-policy">the privacy policy</nuxt-link>
                for more information.
            </p>
        </div>
        <div class="flex justify-center mt-4 lg:mt-0">
            <div class="button ml-2 md:ml-0" @click="accept">Yes, sure</div>
            <div class="button md:ml-2" @click="deny">&times;</div>
        </div>
    </div>

Next, we will add a data property to track whether the cookie banner should be shown:

data() {
    return {
        isOpen: false
    };
}

We can now create a method to call when the user denies our request to use cookies. If the clicks deny, then we will hide the banner and save their preference to local storage.

deny() {
    if (process.browser) {
        this.isOpen = false;
        localStorage.setItem('GDPR:accepted', false);
    }
}

Similarly, we can create a method to call when the user accepts our request to use cookies. If the user clicks accept, we will hide the banner, save their preference to local storage and bootstrap the vue-gtag plugin.

import {bootstrap} from 'vue-gtag';

export default {
    methods: {
        accept() {
            if (process.browser) {
                bootstrap().then(gtag => {
                    this.isOpen = false;
                    localStorage.setItem('GDPR:accepted', true);
                    location.reload();
                })
            }
        },
        ...
    },
}

We should also make sure the component knows whether the banner should be shown when it is first loaded.

created() {
    if (!this.getGDPR() === true) {
        this.isOpen = true;
    }
},

methods() {
    getGDPR() {
        if (process.browser) {
            return localStorage.getItem('GDPR:accepted', true);
        }
    },
    ...
}

You may be wondering what the bootstrap method is doing here. Happily, vue-gtags allows us to load the plugin conditionally. This means the script will only load when we want it to. Lets' head back to our own analytics plugin and modify the code like this:

import Vue from 'vue';
import VueGtag from 'vue-gtag';

const getGDPR = localStorage.getItem('GDPR:accepted');

Vue.use(VueGtag, {
    config: { id: 'GA_MEASUREMENT_ID' },
    bootstrap: getGDPR === 'true',
    appName: 'APP_NAME',
    enabled: getGDPR === 'true',
});

You can read more about this in the vue-gtag documentation.

Tracking page views

Since we are using vue-router as part of Nuxt JS, we can pass the application router to vue-gtag so that it can associate tracking information with the specific page the user is viewing.

import Vue from 'vue';
import VueGtag from 'vue-gtag';

export default ({ app }) => {
    const getGDPR = localStorage.getItem('GDPR:accepted');

    Vue.use(VueGtag, {
        config: { id: 'GA_MEASUREMENT_ID' },
        bootstrap: getGDPR === 'true',
        appName: 'APP_NAME',
        enabled: getGDPR === 'true',
        pageTrackerScreenviewEnabled: true
    }, app.router);
}

Conclusion

Google Analytics is undoubtedly easy to install, but it takes a bit more work to inform your users that you are using cookies to track their use of your website and give them the option to opt out entirely. This process has made me think about whether this really is the right solution for me. I've been looking into cookie-free, privacy-focused tracking solutions and hope to be able to remove Google Analytics soon. I'd love to hear about how you measure visits to your blog and whether you've used any cookie-free solutions. Let me know in the comments below.

Thank you for reading this article.
I hope you learned something useful.
If you've made it this far, you might like to follow me on Twitter where I post similar content and connect with like-minded people.
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