-> we can use two languages to write Flex applications: MXML and ActionScript.
-> MXML is an XML markup language that you use to lay out user interface components.
-> Like HTML, MXML provides tags that define user interfaces. MXML will seem very familiar if you have worked with HTML.
-> MXML is more structured than HTML, and it provides a much richer tag set.
-> One of the biggest differences between MXML and HTML is that MXML-defined applications are compiled into SWF files and rendered by Adobe® Flash® Player or Adobe® AIR™, which provides a richer and more dynamic user interface than page-based HTML applications.
Simple Flex Application :
<?xml version="1.0"?>
<!-- mxml\HellowWorld.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Panel title="My Application"
paddingTop="10"
paddingBottom="10"
paddingLeft="10"
paddingRight="10"
>
<mx:Label text="Hello World!" fontWeight="bold" fontSize="24"/>
</mx:Panel>
</mx:Application>
Why using UTF-8 in encoding format :
-> UTF-8 provides a unique number for every character in a file, and it is platform-, program-, and language-independent.
<mx:Application> tag :
-> It represents a Application container.
-> A container is a user-interface component that contains other components and has built-in layout rules for positioning its child components.
-> By default, an Application container lays out its children vertically from top to bottom
The MXML properties :
-> We can configure initial state of an component using mxml properties. And We can change this properties using Actionscript at run time.
Relationship of MXML tags to Actionscript classes :
-> Adobe implemented Flex as an ActionScript class library. That class library contains components (containers and controls), manager classes, data-service classes, and classes for all other features.
-> MXML tags correspond to ActionScript classes or properties of classes. Flex parses MXML tags and compiles a SWF file that contains the corresponding ActionScript objects.
For example,
<mx:Button label="Submit"/>
-> When you declare a control using an MXML tag, you create an instance object of that class. This MXML statement creates a Button object, and initializes the label property of the Button object to the string "Submit".
