Appcelerator with Matt Quinlan
This evening I attended the Denver Open Source User Group meeting where the Basic Concepts talk was on Appcelerator. Matt Quinlan (Twitter, Blog, LinkedIn) was the presenter. I arrived 10 minutes late, so I didn't hear any of the intro stuff. Below are my notes from the event.
The Appcelerator developers liked the "onclick" syntax, but found it was too limited to do everything they wanted. Rather than onclick, they use an on attribute. For example:
<div on="click then l:show.box"> Click me <div>
"DOM Manipulation is JavaScript cruft."
Appcelerator allows you to implement the Observer pattern in the browser. In addition to allowing DOM elements to subscribe to messages, server-side objects (in any language) can subscribe as well. In Appcelerator syntax "l:" means local and "r:" means remote. The messages that are passed to the server are JSON and have payloads. JSON is more popular than XML because you can eval() it and create JavaScript objects from it. Appcelerator allows you to do Declarative Ajax. On the server-side, you can annotation Java and C# classes with @Service to subscribe to messages. In other languages (i.e. PHP), Javadoc-style comments are used.
Tagline: The seamless fusion of RIA and SOA.
Web Expression Language
Goal is to eliminate 90% of the JavaScript you write. Example syntax:
on="[condition] then [action]"
Conditions include DOM events (click, focus, blur, change, mouse events), key events (up, down, press), other (history, drag/drop, selected, resize, iPhone orient, sortXYZ), subscribe to custom message. Actions include Scriptaculous effects (show/hide, fade, move, drop, grow), set element value (static, dynamic, bind), set CSS class or attribute, execute custom JavaScript, publish custom message.
Now Matt is doing a demo on http://try.appcelerator.org. This site consists of a form that allows you to type in Appcelerator code and run it. 3 attributes can be added to any tag: draggable, droppable and resizeable.
Client-Side
Add simple tags to your HTML to inject RIA widgets. Add single property to existing HTML elements for dynamic behavior. Eclipse Plugin built on Aptana, but is generally targeted towards web developers moreso than business analysts (no drag and drop of widgets).
Server-Side
Server-side development done with your IDE of choices. Based on your server-side tehchnology platform. Easily create services using annotations.
App Command
The app command is similar to Rails' GEM command. Allows you to build scaffolding and deploy to cloud (AppEngine, Amazon S3). It also allows you to pulldown components from the main server and auto-updating.
Examples:
- appTunes: widget that wraps Flex Cover Flow widget
- Snapshot: photo editing application
- Radio Javan: Persian music online
- SkyBlox: wireless company
Appcelerator allows you to create prototypes easily by using a JavaScript file with mocks for the server-side objects. In the next version, you can "annotate" the UI and allow end-users to Ctrl+Click on elements and add feedback. For an example of this, see http://dev.appcelerator.com/pearson.
When starting with Appcelerator, you can start by crawling (including appcelerator.js for widgets) then move to walking (decouple server-side and client-side) and finally running (developing working prototypes with mocks for server-side).
"Let's face it, ASP, JSP, PHP and Ruby are just lipstick on CGI."