Book Image

Ext JS 4 Plugin and Extension Development

By : Abdullah Al Mohammad
Book Image

Ext JS 4 Plugin and Extension Development

By: Abdullah Al Mohammad

Overview of this book

Ext JS is a pure JavaScript application framework for building interactive web applications using techniques such as Ajax, DHTML, and DOM scripting. Ext JS 4 Plugin and Extension Development is a practical, step-by-step tutorial which guides you to learn and develop ExtJS plugins and extensions. There are a lot of examples with explanations and plenty of code provided to make it easier and quicker to pick up. Starting with the fundamentals, this book introduces some of the ExtJS library and community provided plugins and extensions and finishes with several hands-on, real world development examples. You will get a clear concept of ExtJS plugins and extensions and learn how to use them. You will also learn how to develop an ExtJS plugin and extension by going through several examples with code and screenshots. Ext JS 4 Plugin and Extension Development book will provide you with the knowledge to develop ExtJS plugins and extensions using real-life examples.
Table of Contents (16 chapters)
Ext JS 4 Plugin and Extension Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Planning and coding the chart downloader


The plugin's container may or may not have the bottom bar, so we need to search for the bottom bar within the container. If found, we will use that, otherwise we need to create the bottom bar, and then we can add the download button to that bottom bar.

Now let us start coding for the plugin.

Ext.define('Examples.plugin.ChartDownload', {

  alias : 'plugin.chartdownload',

  config : {
    chartXtype: 'chart',
    downloadButtonText: 'Download as image',
    chartNotFoundErrorMsg: 'No valid chart type found!',
    errorText: 'Error'
  }
…

Here we are providing a configuration option chartXtype so that we can configure this plugin with a proper xtype of the chart, which we are targeting to download as an image. Now let us define the required init function for this plugin:

init : function(container) {

  this.container = container;

  if (!container.rendered) {
    container.on('afterrender', this.handleAfterRender, this);
  } else {
    this.handleAfterRender...