It is possible to define your component types within projects. Custom and composite components can be added to the palette for use with createComponent(). Custom widgets are single custom widgets and composites are pages turned into widgets.
A simple example of a custom widget can be found in the common/packages/example folder of the WaveMaker home folder. It is a button that changes color and cursor during mouse-over movements using pre-connected mouseout and mouseover events called myButton.js. By extending the wm.Button type, myButton inherits the functionality of a button, so it only needs to add the calls to connect and the page functions that would otherwise go in page code. Information about building custom components can be found at http://dev.wavemaker.com/wiki/bin/wmdoc_6.5/Custom+Components.
The composite mechanism available in WaveMaker 6.5 is limiting and will not be covered here. A new mechanism has been introduced with WaveMaker 6.6. For information on 6.5...