ministryofjustice/peoplefinder

// The following script sends the page load time per page to GA

moj.Modules.LoadTime = {

    labels: {
        excellent: 'Under 1 second (Excellent)',
        veryGood: '1 to 2 seconds (Very good)',
        acceptable: '2 to 3 seconds (Acceptable)',
        improve: '3 to 5 seconds (Try improving)',
        fix: 'More than 5 seconds (Needs fixing)'
    },
    category: 'Page load time',

    init: function() {
        window.onload = function() { setTimeout('moj.Modules.LoadTime.pageLoaded()',1000); }
    },

    pageLoaded: function() {
        if(typeof ga === 'undefined') return;
        
        var loadTime = this.getLoadTimeSeconds();
        if(!loadTime || isNaN(loadTime)) return;
        
        var pageName = this.getPageName();
        if(!pageName) return;        
        
        var label = this.labelLoadTime(loadTime);
        
        this.sendEventToGoogle(pageName, label, loadTime);
    },

    getLoadTimeSeconds: function() {
        if(typeof performance === 'undefined' || !performance || !performance.getEntriesByType 
            || !performance.getEntriesByType('navigation')[0]) return false;

        return performance.getEntriesByType('navigation')[0].duration / 1000;
    },

    getPageName: function() {
        return document.title ? document.title.split('-')[0] : '';
    },

    labelLoadTime: function(loadTime) {
        with(this)
            return     loadTime < 1 ? labels.excellent : 
                             loadTime < 2 ? labels.veryGood : 
                             loadTime < 3 ? labels.acceptable : 
                             loadTime < 5 ? labels.improve : labels.fix;
    },

    sendEventToGoogle: function(pageName, label, loadTime) {
        ga('create', 'UA-53656606-1');
        ga('send', 'event', this.category, pageName, label, parseInt(loadTime));
    }
}