ExtJS ComboBox Hidden Field Issues

Mar 09

ClaudeExt JS, Tutorials , , , No Comments

As you might already know, despite looking like a typical select box, Ext.form.ComboBox doesn’t behave exactly as you would expect since it submits the display text instead of the option value. The documentation states:

A ComboBox works in a similar manner to a traditional HTML <select> field. The difference is that to submit the valueField, you must specify a hiddenName to create a hidden input field to hold the value of the valueField. The displayField is shown in the text field which is named according to the name.

this.add([
	{
		xtype: 'combo',
		name: 'suffix',
		hiddenName: 'suffixId', // post this name
		hiddenValue: 0, // default value
		fieldLabel: 'Suffix',
		mode: 'local',
		store: this.suffixStore,
		valueField: 'key',
		displayField: 'display',
		triggerAction: 'all',
		forceSelection: true,
		allowBlank: true
	}
]);

Adding a hiddenName and a default value in hiddenValue does the trick, the default value (0) is set in the hidden field until a user chooses a different value. Unfortunately this breaks when the ComboBox is set to allow blanks and the user tabs over the field. When this happens, the hiddenValue is set to a null string and the user is never prompted to select a value.

Upon form submission, the hiddenField (suffixId) will be set to neither the default or a valid value.

One solution is to listen for the focus and blur events to reset the value of the hidden field when it has been set to a null string.

this.add([
	{
		xtype: 'combo',
		name: 'suffix',
		hiddenName: 'suffixId',
		hiddenValue: 0,
		fieldLabel: 'Suffix',
		mode: 'local',
		store: this.suffixStore,
		valueField: 'key',
		displayField: 'display',
		triggerAction: 'all',
		forceSelection: true,
		allowBlank: true,
		listeners: {
			'focus': this.handleSuffixChange,
			'blur': this.handleSuffixChange,
			scope: this
		}
	}
]);

handleSuffixChange: function(field) {
	if (field.value=='') {
		field.hiddenField.value = '0';
	}
}

Upon form submission you will be guaranteed a valid value, which is especially beneficial if you’re using the form values to populate a server side bean object.

Introduction to Ext.Direct

May 13

ClaudeArticles, Ext JS, Framework, JavaScript, Platform, Protocol , , , , , , , , , No Comments

Evan Trimboli of the Ext-JS team just published an article describing Ext.Direct, a remoting API that is part of Ext 3.0. The team has created a remoting specification that you can use to implement the server-side stack of your choice.

Details about server-specific implementations already being maintained can be found here.

Ext.Direct is a new package in Ext JS 3.0 that helps alleviate many of these issues by streamlining communication between your client and server. When using Ext.Direct, you can expect to write 30% less code by eliminating common boiler plate code.

The Ext.direct namespace introduces several new classes for a close integration with the server-side. New classes have also been added to the Ext.data namespace for working with Ext.data.Stores which are backed by data from an Ext.Direct method.

Ext.Direct uses a provider architecture, where one or more providers are used to transport data to and from the server. There are several providers that exist in the core at the moment, for example a JsonProvider for simple JSON operations and a PollingProvider for repeated requests. One of the most powerful providers is the RemotingProvider.

Read the rest here.

Ext-JS Conference 2009, April 14-16 in Orlando, FL

Feb 03

ClaudeExt JS , , , No Comments

Ext-JS has announced their 1st Annual Ext Conference and Ext 3.0 release party on April 14 to 16, 2009 in Orlando, Florida! Join Jack and the Core Development Team for an intense 3-day conference exploring all of the new features packed into Ext 3.0. Discover best practices for building applications and connect with other members of the Ext Community. The conference provides sessions which will be of interest to all parties involved in application development including managers, designers, developers and application architects.

New Book: Learning Ext-JS

Dec 09

ClaudeBook, Ext JS, JavaScript , , , , No Comments

Steve “Cutters” Blades’ book on Ext-JS is out.

By using a series of straightforward examples backed by screenshots, Learning Ext JS will help you create web applications that look good and perform beyond the expectations of your users. This book is written for Web Application Developers who are familiar with HTML but may have little to no experience with JavaScript application development. If you are starting to build a new web application, or are re-vamping an existing web application, then this book is for you.

Get your copy today.

Ext-JS JSON Data Reader For ColdFusion

Nov 21

ClaudeExt JS, JavaScript , , , , , No Comments

Steve “Cutter” Blades has created a custom JSON Data Reader for ColdFusion, CFQueryReader. It allows Ext-JS developers to populate GridPanels using serialized ColdFusion queries in their native format or formatted for grid. CFQueryReader is designed to accommodate either format automatically.

Ext-JS to Provide Free CDN Hosting for its Framework

Nov 18

ClaudeExt JS, Framework, JavaScript, Platform , No Comments

This is great news for the Ext-JS community. Here is why you should take advantage of a content delivery network.

We are pleased to announce that Ext has partnered with CacheFly, a global content network, to provide free CDN hosting for the Ext JS framework. Cachefly’s globally distributed network and aggressive caching accelerate the delivery of web content like JavaScript and CSS, making for an even faster Ext experience.

The Ext CDN also provides the ability to create your own custom builds using Ext’s Build It! tool, and host them on the CDN. The custom builder implements features to intelligently cache your component selections, adapter, and Ext version to create a unique custom build. These custom builds are cached across sessions and used by anyone who makes the same selections as you have – allowing for caching of custom builds across applications to fully realize the benefits of the CDN.

Ext-JS Extension for Google Earth API

Nov 15

ClaudeExt JS, JavaScript , , , , , No Comments

Bjørn Sandvik, a project manager at the United Nations Association of Norway has created an Ext-JS user extension for Google Earth. The code and examples are here.

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