The export extension point should also provide the parameters

It could be a good idea to manage the parameters in the extension point definition rather than in the code with a 'hasParameters' method to be implemented (without providing a method to know what are the parameters...).

Actually parameters are guessed by calling 'getParameters', if they have been initialized in the exporter's constructor.

If the exporter extension point provides the parameter definition, in its schema, it would be easier to manage them and to define the comment for each. A parameter could contain : name, required/optional, description, ....

Then this list of parameters can be reused to initialize the export wizard and to initialize properly the expected parameters list for export...

This issue concerns also importers when they will be defined.