somtodaynt/content/js/index.js

console.log('Somtoday\'nt content script active');

function changeSlogan(message) 
{
    tonight = message[0];
    slogans = message[1];

    // Select random slogan
    console.log(`Loaded ${slogans.length} slogans`);
    if (slogans.length >= 1) {
        var random = Math.floor(Math.random() * slogans.length);
        var sloganText = slogans[random].toLowerCase();
        console.log(`Slogan changed to: ${sloganText}`);
    } else {
        var sloganText = "welkom bij somtodayn't";
        console.log('No slogans found')
    }
    
    // Split the slogan into array
    var sloganArray = sloganText.split(" ");
    var slogan = {
        white: '',
        blue: ''
    };
    
    // Set the last word in the array to be blue
    if (sloganArray.length > 1) {
        slogan.blue = sloganArray.pop();
        for (let index = 0; index < sloganArray.length; index++) {
            slogan.white = slogan.white + sloganArray[index] + " ";
        }
    } else {
        slogan.white = sloganArray;
    }
    
    // Edit HTML
    document.getElementById('slogan').innerHTML = 
        `<span class="white block">${slogan.white}</span>
         <span>${slogan.blue}</span>`
    ;

    // Add a little credit
    document.querySelectorAll('footer > span')[0].innerHTML = "Somtodayn't is een add-on door McArn.";

    // Set theme
    console.log(tonight);
    if (tonight) {
        var cssUrl = browser.runtime.getURL("content/css/index.css");
        var cssTag = `<link rel='stylesheet' href='${cssUrl}'>`;
        document.body.innerHTML += cssTag;
    }
}

// Send request to background script
browser.runtime.sendMessage({ type: "get"});

// Receive response from background script
browser.runtime.onMessage.addListener(changeSlogan);