Book Image

ASP.NET jQuery Cookbook - Second Edition

By : Sonal Aneel Allana
Book Image

ASP.NET jQuery Cookbook - Second Edition

By: Sonal Aneel Allana

Overview of this book

jQuery is a lightweight JavaScript library that has changed the landscape of client scripting in web applications. Developed by John Resig in 2006, it has taken the web by storm because of its cross-browser compatibility and the ability to get more done with less code. It has gained popularity with ASP.NET developers and is now distributed with Visual Studio and the NuGet package manager. ASP.NET jQuery Cookbook explores the wide range of utilities that the jQuery library provides. It teaches you the nitty-gritty of plugging in these features in ASP.NET web applications. It covers every aspect of interfacing the library, right from downloading and including jQuery on web pages to selecting controls, handling events, and creating animations. This book also walks you through DOM traversal and manipulation in ASP.NET and then through visual effects and graphics in ASP.NET sites. It explores advanced features such as posting AJAX requests and writing plugins. It will provide you with all the information you need to use this library confidently with ASP.NET.
Table of Contents (15 chapters)
ASP.NET jQuery Cookbook Second Edition
About the Author
About the Reviewer

Using CDN to load jQuery in MVC

Because of the advantages of using CDN in web applications, bundling also supports the loading of files directly from CDN. This recipe will explain how a MVC project can be configured to use CDN.

Getting ready

This recipe is a continuation of the previous recipe, Bundling jQuery in ASP.NET MVC. So, follow all the steps described in the previous recipe.

How to do it…

Following are the steps to load jQuery in MVC:

  1. In the BundleConfig module/class, modify the RegisterBundles method in order to set the UseCdn property to true, as shown in the code snippet in step 2.

  2. Declare the required CDN path, and add a ScriptBundle with two parameters: the virtual path of the bundle and the CDN path, as follows:

    For VB, the code is as follows:

    Public Module BundleConfig
       Public Sub RegisterBundles(ByVal bundles As BundleCollection)
          bundles.UseCdn = True
          Dim cdnPath As String =  ""
    bundles.Add(New ScriptBundle("~/Scripts/jquery", cdnPath).Include("~/Scripts/jquery-{version}.js"))
       End Sub
    End Module

    For C#, the code is as follows:

    public class BundleConfig
        public static void RegisterBundles(BundleCollection bundles)
            bundles.UseCdn = true;
            string cdnPath = "";
            bundles.Add(new ScriptBundle("~/Scripts/jquery", cdnPath).Include("~/Scripts/jquery-{version}.js"));

How it works…

Following are the steps to load jQuery in MVC using CDN:

  1. By setting the UseCdn property, serving of bundled scripts from the CDN is enabled.

  2. In the development mode, the application retrieves files from the local Scripts folder. In the release mode, the CDN path is used to serve the bundled scripts.

  3. However, there is a possibility that the CDN is down. Hence, a fallback mechanism is required so that the scripts are served locally in such a scenario. This can be done by adding the following <script> block in the required view:

    <script type="text/javascript">
       if (typeof jQuery == 'undefined') {
          var e = document.createElement('script');
          e.src = '@Url.Content("~/Scripts/jquery-2.4.1.js")';
          e.type = 'text/javascript';

See also

The Hello World in ASP.NET MVC using jQuery recipe