General Dynamics to host an Ext JS and JavaScript Meetup

After a successful and full meetup at Three Pillar Global on 1/19/2010, General Dynamics has graciously invited us to host a meetup at their Northern Virginia location. Pat Sheridan and Jay Garcia have selected two key topics that are essential to building dynamic and robust Ext JS applications.

About the presentations:

Theming Ext JS, Pat Sheridan

I’ll give some practical code walkthrough on understanding the default theme CSS, using Renderers, and writing/ overriding Ext Templates to give your app a unique look and feel.

Using Base Classes, Jay Garcia

Jay will explore the benefits of using base classes to improve and standardize application infrastructure.
He will walk through a real time example writing a base class and two implementation classes.

Food and refreshments to be provided. We look forward to seeing you there!

Address:

Where:
General Dynamics
15000 Conference Center Drive
Chantilly, VA 20151

RSVP Link: here.

The official ExtJS.com/forum link here.

About the presenters:

Pat Sheridan is a successful Ext JS developer that leverages his user experience background to accelerate successful development with RIA JavaScript frameworks, including Ext JS. With success stories such as the complete rewrite of the U.S. Treasury’s Pay.gov website and the production of four large RIA applications for the Financial Regulatory Authority (FINRA), he continues to dominate this space with a progressive thought process that enhances the development and user experience alike. He demonstrated his UX leadership with the release of an Ext JS 2.0 OmniGraffle template that has garnered over 50,000 downloads world wide.

Jay Garcia, author of the up and coming book, Ext JS in Action (http://extjsinaction.com/), provides daily support on the Ext JS forums as well as free extensions and widgets to the library. He is an author for JSMagazine, the Ext JS blog and his own blog at http://tdg-i.com. He’s developed enterprise-level applications using Ext JS since early 2006, when it was known as “yui-ext” and has continued to support and assist in the expansion of the product ever since.

Thank you!

Our Ext JS meetup on 1/19/2010 at Three Pillar Global was rather successful! We had over 30 developers show up with less than three weeks notice of the event. This caused an overflow of visitors, where they had to sit outside of the room.

Some photos

Pat Sheridan:

Shea Frederick

Jonathan Julian

The Audience

Videos: More to follow after the other presenters approve their presentation videos

Three Pillar Global plays host to a an Ext JS gathering

At 6:30PM on 1/19/2010, Three Pillar Global (formally Three Pillar software) will be hosting a gathering of industry leading minds in the metro DC area to discuss and share development practices, ideas, tips and tricks revolving around the Ext JS framework. There will be four presentations that are jam-packed with information that can aid to your success in developing applications with the Ext JS framework

About the presentations:

Patrick Sheridan will kick off the meeting, where he will explain how analysis-driven development can aid in the success of your application construction, reducing time from conception to production. Shea Frederick will be guiding us through advanced JavaScript debugging techniques, demonstrating some of the best tricks for the latest and greatest JavaScript development tools. Jonathan Julian is going to share and elaborate on five areas to improve your Ext JS applications, which range from defining your own components to properly overriding the framework. Lastly, Jay Garcia will discuss how to build extensible applications using a two-tiered approach with Ext JS.

Food and refreshments to be provided. We look forward to seeing you there!

Address: (click to launch google maps)

4000 Legato Rd
Fairfax, VA 22033

RSVP Link: here.

About the presenters:

Pat Sheridan is a successful Ext JS developer that leverages his user experience background to accelerate successful development with RIA JavaScript frameworks, including Ext JS. With success stories such as the complete rewrite of the U.S. Treasury’s Pay.gov website and the production of four large RIA applications for the Financial Regulatory Authority (FINRA), he continues to dominate this space with a progressive thought process that enhances the development and user experience alike. He demonstrated his UX leadership with the release of an Ext JS 2.0 OmniGraffle template that has garnered over 50,000 downloads world wide.

Shea Frederick is an active community member for ExtJS. His expertise is drawn from community forum participation, work with the core development team, and his own experience as the architect of several large ExtJS-based web applications. Shea is also an author for JavaScript Magazine, his own blog (http://vinylfox.com), and the Ext JS blog. He is the lead author of the Learning Ext JS book and is the organizer for the Baltimore JavaScript developers meetup group.

While not very well known in the Ext JS community, Jonathan Julian is successful independent web developer specializing in Rails and Ext JS applications with extensive experience in Java and related technologies. He occasionally blogs about software and web development at jonathanjulian.com and tweets as @jonathanjulian. He has presented at the Baltimore JavaScript developers meetup group.

Jay Garcia, author of the up and coming book, Ext JS in Action (http://extjsinaction.com/), provides daily support on the Ext JS forums as well as free extensions and widgets to the library. He is an author for JSMagazine, the Ext JS blog and his own blog at http://tdg-i.com. He’s developed enterprise-level applications using Ext JS since early 2006, when it was known as “yui-ext” and has continued to support and assist in the expansion of the product ever since.

Yesterday, JSMag team released the November 2009 edition of their monthly e-periodical. In this edition, you can find my Ext JS component life cycle article and an awesome IDE comparison by a fellow community leader, Shea Frederick.

The first 10 people to use coupon code “3z2u8hh” to get this month’s edition for free.

Click on the image below or visit http://jsmag.com/latest to get your copy.

Many times Ext JS developers are required to extend or add functionality to a widget in the framework.  Some of the solutions include creating an actual extension using Ext.extend or even creating a plugin.  If the requirement is a only for a single-use and is relatively simple to implement, creating an extension or plugin class is overkill.   So the question is, what is the best solution for this type of situation?

I say it’s override and extend on-the-fly at the configuration object, which is possible for just about every class in the framework.   We’ll go into exactly how this works in just a bit.  Before that, I’d like for you to ponder a simple requirement, and we’ll explore an extremely simple one-off solution.

Requirement: Display an Ext JS Window that when closed, a confirmation dialog is requested.  If the actor presses “yes”, then the instance of Window actually closes with an alert confirming the window closing.  OK, I know that it sounds a little silly.  Trust me, in the nearly four years I’ve been developing applications with this framework, silly requirements like this have been presented to me.

OK, how do we solve this easily?  Here is an example that extends the close method, and introduces a new method (alertClose) to the instance of Ext.Window to be created.

Here’s how this works.  In the above code, we extend the close method.  The reason I choose the word “extend” is because, just like when creating an actual extension, we have the ability to call the Window.prototype.close method, which actually will complete the original execution flow.  If we chose not to call the prototype.close method, then this technically would be an override.

The close method will display the Ext.MessageBox.confirm dialog.  The dialog’s callback is an anonymous method that is scoped to the instance of Window that is being created.  It inspects the Button id, which defaults to ‘yes’ or ‘no’.  If the actor clicks ‘yes’, then the  newly added this.alertClose method is called,  alerting the actor that the window closed.  This is  followed by an Ext.Window.prototype.close is call, actually closing (and destroying) the instance of Window that is created.

If the actor clicks the “no” button, then the confirmation dialog hides and all is well again.  Below is the UI flow of the code above.

I’m sure you’re probably thinking: “Wait a minute?!  How the heck is that possible?”  It’s possible because in most classes, the following line exists in the constructor:
Ext.apply(this, config);

This line basically applies whatever is in the configuration object to the instance of the class (this), thus setting override parameters and methods.  This, of course, includes any new methods, such as alertClose (above).

Here it is in Ext.Component (Ext.Window is a descendant of Ext.Component):

And there you have it, you now know how to extend and override a single instance of a class without creating an extension or override.

Extensions and plugins are not obsolete however.  They still retain their value and hold their place in this world.  After I write the “Extensions and Plugins” chapter of Ext JS in Action, I’ll follow up with a somewhat comprehensive guide to constructing these.