Before you begin to write a custom data handler, it is recommended that you clearly understand:
In particular, you need to know how to:
For your custom data handler to be meta-data-driven, it must dynamically specify information that identifies the data handler to use. For more information on meta-data-driven data handlers, see Meta-data-driven data handler design.
One of the design decisions you need to make is whether you data handler will use meta-objects to initialize its configuration.
Consider the following when deciding whether to use meta-objects:
To call a data handler that uses meta-objects, the caller passes the data handler's associated MIME type into the createHandler() method. When called with a MIME type, createHandler() initializes a newly instantiated data handler with the configuration information in the child meta-object.
To call a data handler that does not use meta-objects, the caller passes only the data handler's class name into the createHandler() method. When called with a class name, createHandler() instantiates a data handler of that class; it does not search for associated meta-objects.
If you design your custom data handler to use meta-objects, you need to create these meta-objects as part of your data-handler implementation. For more information, see Creating data-handler meta-objects.