Editing Properties Of Writers
There is currently no way to configure a writer before saving data in ParaView 3. For example, you may want to tell the writer whether or not to write out ghost cells or whether or not to write out all the timesteps.
Fortunately, the functionality is almost all implemented to support editing a writer's properties. The pqAutoGeneratedObjectPanel class enables editing of a pqProxy's properties via automatically generated Qt widgets based on the property types. Thus, any properties defined in writers.xml for a given writer will be editable from this interface (except for the filename and input proxy).
What's left to do is write a pqWriter class that inherits from pqProxy. pqServerManagerObserver will create a pqWriter object when a proxy is registered in the server manager that is a member of the "writers" group. pqMainWindowCore could be notified of this and create the pqAutoGeneratedObjectPanel in a new QDialg box.