SharePoint-Hosted Get Host Lists

'use strict';

var context = SP.ClientContext.get_current();
var user = context.get_web().get_currentUser();
var web = context.get_web();

var hostWeb;
var hostweburl;
var appweburl;

// This code runs when the DOM is ready and creates a context object which is needed to use the SharePoint object model
$(document).ready(function () {
    InitCrossContext();
    getUserName();
});

function InitCrossContext() {
    hostweburl = decodeURIComponent(getQueryStringParameter('SPHostUrl'));
    appweburl = decodeURIComponent(getQueryStringParameter('SPAppWebUrl'));
    var scriptbase = hostweburl + '/_layouts/15/';

    // Permet l'exécution sur un autre domaine (Site hôte) :
    $.getScript(scriptbase + 'SP.RequestExecutor.js', printAllListNamesFromHostWeb);
}

function printAllListNamesFromHostWeb() {
    // Prépare le contexte d'exécution vers l'hôte :
    var contextHost = new SP.ClientContext(appweburl);
    var factory = new SP.ProxyWebRequestExecutorFactory(appweburl);
    contextHost.set_webRequestExecutorFactory(factory);
    var appContextSite = new SP.AppContextSite(contextHost, hostweburl);

    // Batches de chargement des informations :
    this.hostWeb = appContextSite.get_web();
    var collList = this.hostWeb.get_lists();
    contextHost.load(this.hostWeb);
    contextHost.load(collList);

    contextHost.executeQueryAsync(
        Function.createDelegate(this, successHandler),
        Function.createDelegate(this, errorHandler));

    function successHandler() {
        var listInfo = '';
        var listEnumerator = collList.getEnumerator();
        while (listEnumerator.moveNext()) {
            var oList = listEnumerator.get_current();
            listInfo += '<li>' + oList.get_title() + '</li>';
        }

        $("#distantLists").html('<p>Web Title (Host) : ' + this.hostWeb.get_title() + '</p><p>X - Lists found:</p><ul>' + listInfo + '</ul>');
    }

    function errorHandler(sender, args) {
        document.getElementById("message").innerText = "Could not complete cross-domain call: " + args.get_message();
    }
}

// This function prepares, loads, and then executes a SharePoint query to get the current users information
function getUserName() {
    context.load(user);
    context.load(web);
    context.executeQueryAsync(onGetUserNameSuccess, onGetUserNameFail);
}

// This function is executed if the above call is successful
// It replaces the contents of the 'message' element with the user name
function onGetUserNameSuccess() {
    $('#message').text('Hello ' + user.get_title());
    $('#localLists').text('Web title (local) : ' + web.get_title());
}

// This function is executed if the above call fails
function onGetUserNameFail(sender, args) {
    alert('Failed to get user name. Error:' + args.get_message());
}

function getQueryStringParameter(paramToRetrieve) {
    var params =
        document.URL.split("?")[1].split("&");
    var strParams = "";
    for (var i = 0; i < params.length; i = i + 1) {
        var singleParam = params[i].split("=");
        if (singleParam[0] == paramToRetrieve)
            return singleParam[1];
    }
}