Rich Internet ApplicationsWith PHP, REST, and ExtJS

Traditional Web Apps• All processing done on the server• Every request means reloading the

entire page• UI limited to widgets provided by HTML

RIAs• Features of traditional desktop apps• UI processing done on the browser

– Widgets– Events– Page redraws

• Data manipulation and storage done on the server

• Asynchronous communication

Benefits of RIAs• Richer UI (grids, trees, drag-n-drop)• More responsive• Free up server resources• No need to distribute (as opposed to a

desktop app)• They are sexy

Drawbacks• Depend on JavaScript and a modern

browser• Give away control• Breaks the “Web Pages” paradigm• Accessibility Issues• Probably bad for search engines

When to use them• Web Applications as opposed to Web

Sites• Replacement for desktop app• Enhancement to a traditional webapp

ExtJS• Great widgets and utilities

– Grids, Trees, Forms, Dialogs, etc.– Ajax, DOM, JSON, XML parsing, etc.

• Excellent API, very consistent• Compatible with modern browsers:

– Internet Explorer 6+ – Firefox 1.5+ (PC, Mac) – Safari 2+ – Opera 9+ (PC, Mac)

• Independent of server-side technology• Good looking themes• A bit of a learning curve

Let’s Try it!!

REST• Architectural style for inter-system communication• Treats data as resources• Based on the HTTP protocol• Alternative to RPC style of communication

RPC Style (methods) REST Style (resources)

getUser() addUser() removeUser() updateUser() getLocation() addLocation() removeLocation() updateLocation() listUsers()listLocations()

http://example.com/users/ http://example.com/users/{user} http://example.com/findUserForm http://example.com/locations/ http://example.com/locations/{location} http://example.com/findLocationForm