Unsupported features
MXHX is heavily inspired by MXML, a markup language originally introduced in Macromedia Flex. However, not all features of MXML are supported by MXHX at this time. Some missing features may be implemented in future versions of MXHX, as need arises and time allows.
Component className attribute
The className attribute of the Component tag may be used in MXML to specify an AS3 class name to associate with the generated inline component. Specifying a className attribute for an inline component with the <mx:Component> tag is currently unsupported in MXHX.
Library and Definition tags
The <mx:Library> and <mx:Definition> tags were supported in MXML to provide reusable XML graphical assets to an MXML component. They are currently unsupported by MXHX. However, developers may find that the <mx:Component> tag is sufficiently similar.
Metadata tag
The Metadata tag was supported in MXML as a way to define AS3 metadata, like [Event], on an MXML class. A similar <mx:Metadata> tag for Haxe metadata, like @:event, will be added in a future version.
Model data binding
Binding syntax with curly braces is supported inside an Model tag in MXML, but the <mx:Model> tag in MXHX does not support binding at this time. An error will be reported.
Root implements attribute
The implements attribute was supported in MXML to add an interface to the generated class. It is currently unsupported by MXHX.
Script tag
In Flex, developers can declare fields and methods on an MXML class using a <mx:Script> tag. This is currently unsupported in MXHX. Support for scripts involves integrating a custom Haxe language parser (that will need to be written in Haxe) because the Haxe macro interpreter can only parse expressions inside methods.
Developers can achieve a similar result to an <mx:Script> tag in MXHX by defining fields and methods on a superclass that is written in Haxe, or by using the MXHXComponent.build() macro.
Style tag
In Flex, developers can define CSS (Cascading Style Sheets) in an MXML class using a Style tag. None of the GUI frameworks currently supported by MXHX include support for CSS, so MXHX does not implement a similar <mx:Style> tag yet.
States
In Flex, MXML components could declare states, which allowed the GUI to change appearance and behavior depending on the currently selected state. MXHX does not support states yet, and an error will be reported when attempting to use any of the following syntax for states.
- Setting properties for specific states with
propertyName.stateName="value"syntax - The
includeInandexcludeFromattributes - The
<mx:Reparent>tag
Two-way data binding
Two-way data binding syntax is currently unsupported in all forms, including:
- with curly braces, like
destination="@{source}" - with the
<mx:Binding twoWay="true"/>tag
However, one-way data binding syntax with curly braces or <mx:Binding> tags is supported in MXHX.
XML format attribute
The format attribute of the XML tag can be used in MXML to specify where to use the XML class or the XMLDocument class in AS3, but MXHX does not support a format attribute on the <mx:Xml> tag. The Haxe Xml class is always used. If OpenFL adds an implementation of the XMLDocument class in the future, it may make sense to add support for it to MXHX.
XML data binding
Data binding syntax with curly braces is supported inside an XML tag in MXML, but the <mx:Xml> tag in MXHX does not support data binding at this time. An error will be reported.
XMLList tag
MXML could create an AS3 XMLList object containing a collection of tags. The <mx:Xml> tag in MXHX requires a single root tag, and there isn't an equivalent type for collections of tags in MXHX.