SWC files are similar to SWF files, actually they are ZIP files which contain the following files :

• library.swf : the SWF file containing AVM2 bytecode
• catalog.xml : an XML file describing dependencies between the classes so you can easily link only a part of the API provided by the SWC

Creating SWC with Haxe

In order to compile a .swc file instead of .swf, simply specify an output file which extension is .swc, for example haxe -swf mylib.swc MyLibClasses

If you want to make sure that your whole library is compiled into the SWC you can use the commandline parameter --macro include('mypackage'), that will include all the files declared in the given package and subpackages.

Note: when compiling to a SWC, classes statics initialization order might differ from when compiling to SWF.

Using a Haxe SWC in AS3

In order to use a Haxe-compiled SWC in AS3, you will first need to initialize the Haxe system before doing anything else, by calling :

haxe.init(mc);

mc is a MovieClip that will be stored into flash.Lib.current

Using a SWC/SWF in Haxe

Haxe does not currently support SWC linking. You'll first have to unzip the SWC to extract the library.swf and add it with -swf-lib library.swf to your compiler parameters. As a result, it means that if you're linking a SWC the whole content will be linked with your SWF, not only the part you are using.
Haxe3 supports SWC linking. You no longer need to unzip the swc file manually and can directly link it with -swf-lib library.swc

Accessing classes

Haxe will automatically extract the classes defined inside the SWF if they are not declared in your code, and build a Haxe-compatible type for each of these classes.

While most of the time this will not cause any problem, in some cases you might have to create patch files that contain some changes that you want to apply to the classes before they get generated this way.

Patch files

A patch file consists of several lines which modify existing class field types:

// Removes a class field from Haxe definition
-flash.accessibility.Accessibility.new

// Adds metadata to a given class
@:require(flash10) flash.desktop.Clipboard

// Adds metadata to a given class field
@:require(flash10) flash.display.BitmapData.setVector

// Modifies a given field type
flash.display.DisplayObject.blendMode : BlendMode;

// Modifies a static field type
static flash.system.IME.conversionMode : IMEConversionMode;

// Modifies all function parameters with this specific name
flash.display.BitmapData.$blendMode : BlendMode;

// Modifies a single function parameter
ClassName.$functionName__parameterName : Type;

// Convert a class made of statics vars into an Haxe enum
enum flash.text.TextFieldAutoSize;

Most of these examples are taken from this patch file which is used to patch core flash definitions.

You can use a patch file with --macro patchTypes('patchFile')

hx Classes Generation

Instead of having a SWF and a patch file, you can instead provide a list of .hx files containing extern classes definitions. This class list can be generated from a SWF with the following command :

haxe -swf nothing.swf --no-output -swf-lib library.swf --gen-hx-classes

Using Haxe-compiled SWC from Haxe

Since a lot of type information (such as type parameters) is lost while compiling to SWF/SWC, you should provide a precompiled SWF + the .hx extern files generated with --gen-hx-classes (see upper paragraph)