Quick tip: embedding in Flex

In Flex application, you can embed your assets into 3 places: ActionScript, MXML, CSS. To embed into ActionScript use following syntax:

[Embed(source="assets/image.png")]
public var imageClass:Class;

[Embed(source="assets/library.swf", symbol="symbol1")]
public var symbol1Class:Class;

// flash library symbol alternative
[Embed(source="assets/library.swf#symbol2")]
public var symbol2Class:Class;

To embed into MXML use:

<mx:Image source="@Embed('assets/image.png')"/>
<mx:Image source="@Embed('assets/library.swf', symbol='symbol1')"/>
<mx:Image source="@Embed('assets/library.swf#symbol2')"/>
<mx:Button skin="{null}"/>

To embed asset into CSS file use syntax:

Button 
{
    upSkin: Embed(source="assets/image.png");
    overSkin: Embed(source="assets/library.swf", symbol="symbol1");
    downSkin: Embed(source="assets/library.swf#symbol2");
    selectedUpSkin:ClassReference(null);
}

@font-face 
{
    font-family: Copacetix;
    src: url("assets/copacetix.ttf");
    unicode-range:
        U+0020-U+0040, /* Punctuation, Numbers */
        U+0041-U+005A, /* Upper-Case A-Z */
        U+005B-U+0060, /* Punctuation and Symbols */
        U+0061-U+007A, /* Lower-Case a-z */
        U+007B-U+007E; /* Punctuation and Symbols */
}

Embedding font to .as (.mxml):

[Embed(source="../arial.ttf", fontFamily="myArial")] 
public static const FONT_ARIAL:Class;
public static const FONT_ARIAL_NAME:String = "myArial";

[Embed(source="../fonts.swf", fontName="myCourier", fontWeight="bold|normal") ]
public static const FONT_COURIER:Class;
Font.registerFont(FONT_COURIER);

public function Test()
{
    var format:TextFormat = new TextFormat();
    format.font	= FONT_ARIAL_NAME;
    						
    var tf:TextField = new TextField();
    tf.embedFonts = true;
    tf.defaultTextFormat = format;
}

Read more about embedding assets into ActionScript best practices here. Read basics about embedding here.