Book Image

Ext JS 4 Web Application Development Cookbook

By : Andrew Duncan, Stuart Ashworth
Book Image

Ext JS 4 Web Application Development Cookbook

By: Andrew Duncan, Stuart Ashworth

Overview of this book

<p>Ext JS 4 is Sencha’s latest JavaScript framework for developing cross-platform web applications. Built upon web standards, Ext JS provides a comprehensive library of user interface widgets and data manipulation classes to turbo-charge your application’s development. Ext JS 4 builds on Ext JS 3, introducing a number of new widgets and features including the popular MVC architecture, easily customisable themes and plugin-free charting. <br /><br /><em>Ext JS 4 Web Application Development Cookbook</em> works through the framework from the fundamentals to advanced features and application design. More than 130 detailed and practical recipes demonstrate all of the key widgets and features the framework has to offer. With this book, and the Ext JS framework, learn how to develop truly interactive and responsive web applications.<br /><br />Starting with the framework fundamentals, you will work through all of the widgets and features the framework has to offer, finishing with extensive coverage of application design and code structure.<br /><br />Over 110 practical and detailed recipes describe how to create and work with forms, grids, data views, and charts. You will also learn about the best practices for structuring and designing your application and how to deal with storing and manipulating data. The cookbook structure is such that you may read the recipes in any order.<br /><br />The <em>Ext JS 4 Web Application Development Cookbook</em> will provide you with the knowledge to create interactive and responsive web applications, using real life examples.</p>
Table of Contents (19 chapters)
Ext JS 4 Web Application Development Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Handling Store exceptions


Unfortunately we cannot guarantee that the server will process our stores' requests correctly 100 percent of the time. When the server returns an error or fails to respond, it's useful to be ready to inform our users that something has not worked as expected and perhaps perform extra processing or tidying up. This recipe demonstrates how to handle proxy exceptions and present an error message to the user.

Getting ready

To demonstrate exception handling you will need to ensure that you have a running web server to host the example and serve the provided error-response.json file.

How to do it...

  1. Define the Model that we will attempt to load data into:

    Ext.define('Book', {
        extend: 'Ext.data.Model',
        
        fields: [{
            name: 'Title',
            type: 'string'
        }]
    });
  2. Add an AJAX Proxy to the Model, defining the url config option as error-response.json:

    Ext.define('Book', {
        ...
        proxy: {
            type: 'ajax',
            url: 'error-response.json'
        }
    });
  3. Listen...