Auto Migrate UTM Tags

auto-migrate-utm.js

(MigrateUTM = {
    release: '1.0.2',
    settings: {
        debug: true,
        delay: 2000,
        tags: [
            'utm_medium',
            'utm_source',
            'utm_campaign',
            'utm_term'
        ]
    },
    data: {},
    setEvents: function () {
        this.debug('set events');
        this.getParams();
        this.detectElements();
    },
    detectElements: function () {
        this.debug('detect links');
        var elements = document.querySelectorAll('a[href], form');

        if (!elements.length) {
            return;
        }

        this.debug('total elements: ' + elements.length);

        for (var i in elements) {
            this.migrateParams(elements[i]);
        }
    },
    migrateParams: function (element) {
        var url;
        if (element && element.href) {
            url = this.replaceURL(element.href);
            if (url) {
                element.href = url;
            }

        }
        if (element && element.action) {
            url = this.replaceURL(element.action);
            if (url) {
                element.action = url;
            }
        }
    },
    getParams: function () {
        this.debug('detecte params');
        var urlParams = new URLSearchParams(window.location.search);
        this.data.params = {};

        for (var i in this.settings.tags) {
            var tag = this.settings.tags[i];
            this.data.params[tag] = urlParams.get(tag) || '';
        }

        this.debug('detected:');
        this.debug(this.data.params);
    },
    addParam: function (url, key, value) {

        if (!url || !url.match(/^http/ig) || parseInt(value) === 0) {
            return url;
        }

        this.debug('add param ' + key + ' => ' + value);

        url = new URL(url);
        url.searchParams.append(key, value);

        return url.href;
    },
    replaceURL: function (url) {

        if (!this.data || this.data.params === undefined) {
            return;
        }

        this.debug('replace URL ' + url);

        for (var key in this.data.params) {
            url = this.addParam(url, key, this.data.params[key]);
        }

        return url;
    },
    debug: function (a) {
        if (typeof console === 'object' && this.settings.debug) {
            console.log(a)
        }
    },
    init: function () {
        this.debug('start script');

        if (document.readyState === 'complete') {
            setTimeout(function () {
                MigrateUTM.setEvents();
            }, MigrateUTM.settings.delay);
        } else {
            window.onload = function () {
                setTimeout(function () {
                    MigrateUTM.setEvents();
                }, MigrateUTM.settings.delay);
            }
        }
        return 'MigrateUTM complete';
    }
}).init();

Auto Migrate UTM Tags

Convert and add UTM tags to all links on a page including the action URL of the forms.

Installation method:

Add the script in the "script" tags on your HTML page using the Google Tag Manager or adding directly to the "header" of the template, inside the "head" tag, for that it is loaded on all pages of the your website.

Good luck!