react-google-tag-manager

This repository contains a react based implementation for Google's Tag Manager snippet.

Motivation & Expectation

We like to use Google's Tag Manager in our React Stack. We wrap it into a component because it makes it testable. And based on our agreement every component needs to be tested.
Other requirements for the GTM implementation are:

1. provide a GTM-ID
2. provide additional events on script initialization (optional)
3. provide a name for the dataLayer (optional)
4. can be used for server-side-rendering and client-side-rendering
5. contains tests
6. installable via npm

How to use

To use it in your project run npm i react-google-tag-manager. It could be used like the following example:

import React from 'react';
import gtmParts from 'react-google-tag-manager';

class GoogleTagManager extends React.Component {
    componentDidMount() {
        const dataLayerName = this.props.dataLayerName || 'dataLayer';
        const scriptId = this.props.scriptId || 'react-google-tag-manager-gtm';

        if (!window[dataLayerName]) {
            const gtmScriptNode = document.getElementById(scriptId);

            eval(gtmScriptNode.textContent);
        }
    }

    render() {
        const gtm = gtmParts({
            id: this.props.gtmId,
            dataLayerName: this.props.dataLayerName || 'dataLayer',
            additionalEvents: this.props.additionalEvents || {},
            previewVariables: this.props.previewVariables || false,
        });

        return (
            <div>
                <div>{gtm.noScriptAsReact()}</div>
                <div id={this.props.scriptId || 'react-google-tag-manager-gtm'}>
                    {gtm.scriptAsReact()}
                </div>
            </div>
        );
    }
}

GoogleTagManager.propTypes = {
    gtmId: React.PropTypes.string.isRequired,
    dataLayerName: React.PropTypes.string,
    additionalEvents: React.PropTypes.object,
    previewVariables: React.PropTypes.string,
    scriptId: React.PropTypes.string
};

export default GoogleTagManager;

You can render this later simply by

// inside the render method where you want to include the tag manager
<GoogleTagManager gtmId='GTM-12345' />

// or with all optional parameters
const event = { platform: 'react-stack' }

<GoogleTagManager gtmId='GTM-12345' scriptId='gtm-script-container' dataLayerName='dl-backup' additionalEvents={event} previewVariables='' />

In this example the google tag manager id, the dataLayer name, additional events and the script id where gtm script should be mounted are configurable through props:
| prop | required | default value | | ------------------- | ------------- |-------------------------------- | | gtmId | yes | | | dataLayerName | no | dataLayer | | additionalEvents | no | {} | | scriptId | no | react-google-tag-manager-gtm | | previewVariables | no | false |

Notes:

• The componentDidMount part is required as the script contents itself would not be executed otherwise on the client side
• As eval can be used to do harm, make sure that you are understanding what you are doing here and read through the script that is evaluated
• Additionally this module exports noScriptAsHTML() and scriptAsHTML() which return a simple HTML string
• gtmParts takes the following arguments:

| argument keys | required | default value | | ------------------- | ------------- | ------------- | | id | yes | | | dataLayerName | no | dataLayer | | additionalEvents | no | {} |