Get Host Web Url in SharePoint 2013/Office365 apps using JSOM

Get HostWeb URL through JavaScript object model:

Just do copy/paste the below code and execute it.

Note: The below shared code is 100% verified/executed.

Please reach the below post URL to get the hostweb url through REST service

http://sharepointquicksolutions.blogspot.com/2016/12/get-sharepoint-host-web-url-using-rest.html 


Appmanifest.xml:
Set read level permisisons to the web

Default.aspx:

<p id="getHostWebURL"> </p>

App.js

'use strict';
var hostweburl, appweburl;
var website;

$(document).ready(function () {
    appweburl = window.location.protocol + "//" + window.location.host + _spPageContextInfo.webServerRelativeUrl;
    hostweburl = _spPageContextInfo.siteAbsoluteUrl;

    //hostweburl = decodeURIComponent(getQueryStringParameter("SPHostUrl"));
    //appweburl = decodeURIComponent(getQueryStringParameter("SPAppWebUrl"));
    var scriptbase = hostweburl + "/_layouts/15/";

    $.getScript(scriptbase + "SP.Runtime.js",
        function () {
            $.getScript(scriptbase + "SP.js", retrieveListItems);
        }
    );
});

// Function to retrieve a query string value.
// For production purposes you may want to use
// a library to handle the query string.
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];
    }
}

function retrieveListItems() {
    var context = new SP.ClientContext(appweburl);
    var appContextSite = new SP.AppContextSite(context, hostweburl);
    website = appContextSite.get_web();
    context.load(website);
    context.executeQueryAsync(onGetWebSuccess, onGetWebFail);

    //the remaining code is omitted for clarity  
}

function onGetWebSuccess() {
    alert("calling" + website.get_title());
    $('#getHostWebURL').text("The title of the host web of this app is " + website.get_title());
}

function onGetWebFail(sender, args) {
    alert('Failed to get lists. Error:' + args.get_message());
}