Preface
In this modern world of JavaScript, Ext JS offers a vast collection of cross-browser utilities, a great collection of UI widgets, charts, data object stores, and much more. When developing an application, we mostly look for the best support for the functionality and components that offer the framework. But we almost always face the situation when the framework does not have the specific functionality or component that we need. Fortunately, Ext JS has a powerful class system that makes it easy to extend an existing functionality or component, or to build new functionalities or components.
In this book, we start by providing a very clear concept of Ext JS plugins and extensions with examples, going through several Ext JS libraries and community-provided plugins and extensions and several hands-on developments of real-life, useful Ext JS plugins and extensions.
What this book covers
Chapter 1, Plugins and Extensions, introduces and defines the Ext JS plugins and extensions, the differences between them, and shows how to develop a plugin and an extension with examples.
Chapter 2, Ext JS-provided Plugins and Extensions, introduces some of the very useful and popular plugins and extensions available within the Ext JS library.
Chapter 3, Ext JS Community Extensions and Plugins, introduces some of the popular Ext JS community extensions and plugins.
Chapter 4, Labeled Spinner, goes through hands-on development of an Ext JS extension called Labeled spinner field. This chapter shows how we can extend the Ext.form.field.Spinner class, and add functionality so that this extension can show a configurable label beside the value within the spinner field and some more advanced features.
Chapter 5, Chart Downloader, goes through hands-on development of an Ext JS plugin, which will help to download a chart as an image. This plugin will generate a button that, when it is clicked, will perform the required functionality so that the plugin container's chart item can be downloaded as an image.
Chapter 6, Grid Search, goes through hands-on development of an Ext JS plugin, which will provide a search facility within a grid. This plugin was originally developed by Ing. Jozef Sakáloš and is a very useful and popular plugin. In this chapter, this plugin will be re-written for the Ext JS 4x Version.
Chapter 7, Input Field with ClearButton, goes through hands-on development of Stephen Friedrich's ClearButton plugin. This plugin is targeted for the text components that show a "clear" button over the text field. When the clear button is clicked, the text field is set to empty.
Chapter 8, Message Bar, goes through hands-on development of an Ext JS extension, which will be a fancy animated message bar. The message bar will provide the facility of having a configurable duration timer for showing the message, a close button, and also be able to customize the look, and can provide optional icons for different types of states such as valid or invalid, or information during runtime.
Chapter 9, Intuitive Multi-select Combobox, explores an excellent Ext JS extension, BoxSelect, which was originally developed by Kevin Vaughan. This extension is really very useful and provides a friendlier combobox for multiple selections, which creates easy and individually removable labels for each selection and lots more.
What you need for this book
The examples in this book use the Ext JS 4.1.3 SDK, available from the Ext JS website at http://www.sencha.com/products/extjs/download.
Who this book is for
The book is aimed at web application developers who are familiar with the basics of Ext JS and want to build custom Ext JS plugins and extensions. Experienced Ext JS developers can also increase their skills in the field of Ext JS plugins and extensions.
Conventions
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text are shown as follows: "we will extend the Ext.form.field.Spinner class which will add functionality".
A block of code is set as follows:
onSpinUp : function() {
this.setValue(++this.value);
},
onSpinDown : function() {
this.setValue(--this.value);
}New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "we can find the Get value button within the window".
Note
Warnings or important notes appear in a box like this.
Tip
Tips and tricks appear like this.
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