As with all subclasses, the actual initialization is done in the initialize() function,
not in the constructor, to allow for error handling.
This widget supports all types which have a simple, plain text representation accessible
though their value member.
Available configuration options:
- int width: The number of columns of the textarea, this defaults to 50.
Note that this value might be overridden by CSS.
- int height: The number of rows of the textarea, this defaults to 6.
Note that this value might be overridden by CSS.
- string wrap: Controls the textbox wrapping, defaults to 'virtual' text is
wrapped by the browser, but the automatic wraps are not sent to the server. You
can set this to 'off' or 'physical'. If you set this to an empty string, the
attribute is omitted.