Javascript frameworks are for easing development and dynamic web apps.
These toolkits enables you to deal with Ajax calls in an easy and fun way and it’s also cross browser safe.

It can be handy, if you know already something about JSON:
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write and it is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition – December 1999.
JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.

It’s a personal choice which of the Javascript Frameworks you should choose.
Basically they are all more or less providing you the same functionality, and they all
contain excellent documentation and API’s with examples.
I will show you the 6 most popular frameworks, and tell you the current version,
download link and which websites these frameworks use. Also the size of the .js file,
which is an important detail.

* = compressed gzipped / uncompressed

Flex won’t load data from a server that is not in the domain from which the SWF file originated unless there is a crossdomain.xml in the server’s root.
If you want to allow Flash to access your localhost data, then create a crossdomain.xml file in your public folder, with the following content:

<?xml version "1.0"?>
<cross-domain-policy>
    <allow-access-from domain="*" />
</cross-domain-policy>

Yeah I’m addicted to my Xbox360, and my Xbox Live account.
Developers, check this out:

DunCan Mackenzie created a webservice to retrieve your XboxProfile.

I’m working now on a cool Flex app, which reads my Xbox Profile info.

See the response XML message.

The cool thing about Adobe Flex is that you can run within your mxml file Actionscript.
I love standards and clean code. That’s why I wanted to know how I can run an extern Actionscript.as file.
It’s pretty easy:

1. Create a new folder in your Flex project. – I called it: includes
2. In my mxml I define the extern Actionscript:

include "../includes/scripts.as";
]]>

3. I’ll also define the action into mxml, I want it after a button click:

4. In my includes folder I create an Actionscript: scripts.as:
For example:

import mx.controls.Alert;

private var alert:Alert;

private function init():void {
var alertText:String = “Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Suspendisse rutrum metus nonummy augue. In hac habitasse platea dictumst. Nulla arcu libero, nonummy non, suscipit a, mollis non, augue. Maecenas porttitor urna vel enim. Nam eget tortor. Mauris facilisis suscipit felis. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Proin nunc turpis, venenatis non, laoreet at, fringilla nec, purus. Sed sodales. Sed turpis. Vestibulum sagittis justo id metus. Sed placerat, nibh lobortis mattis adipiscing, sapien wisi interdum arcu, nec vehicula sem tortor id nibh.”;
var alertTitle:String = “The quick brown fox jumped over the lazy dog.”;
alert = Alert.show(alertText, alertTitle);
alert.status = “I’m a status message”;
}

That made my day!