revealing_module_pattern_v2.js

FOO.moduleName = function () {

    // Private variables, global to the module.
    let fieldX; // This value will be changed.
    const foo; // This value will not change.


    /**
     * Constructor
     */
    const init = () => {
        fieldX = document.getElementById('fieldX');
    }

    // https://developer.mozilla.org/en-US/docs/Web/API/Window/DOMContentLoaded_event
    // The DOMContentLoaded event fires when the initial HTML document has been completely loaded and parsed, 
    // without waiting for stylesheets, images, and subframes to finish loading.
    // Call the constructor when the DOM is ready.
    document.addEventListener("DOMContentLoaded", init);

    /**
     * Can't be called externally.
     */
    const privateFunction = () => {
        const fieldY = document.getElementById('fieldY');
        const fieldXvalue = fieldX.value;
	}

    /**
     * Will be returned by the module, to be called externally.
     */
    const publicFunction = () => {

    }
    
    return {
        publicFunction: publicFunction
    }

}();