Single Tool or App for multiple DataFormats or viewTypes

Hello:

I am defining several DataFormats in a data.reg.  I would like to be able to use a single application to open several views with different file extensions.  When I try to assign two different dataformat with different extensions to the same application, it doesn't work.  Only the last definition listed in the data.reg (format_B in the example) shows up when I try to create a new cell view.  When I try checking deGetAppInfo with the first defintion, deGetAppInfo("format_A") below, it comes back empty, but deGetAppInfo("format_B") gives the expected result. Do I have to make a unique App/Tool for every cellview?  I would prefer one application definition since all the views, each pointing to files with different extensions, use the same callback code to start the application since the application supports multiple formats.

Also, the deRegApp documentation refers to view subtypes and says you can sobclass any number of parent types.  However I couldn't find a definition to these terms or a clear explanation of what they are.  Is that just for inheriting the callbacks from the parent viewType or is there more to it?  Would it help with this issue?

data.reg for Example:

DataFormat format_A {
Pattern = *.extA;
Preferred_Editor = exampleEditor;
Default_Editor = exampleEditor;
dfII_ViewType = format_A;
Co_Managed = master.tag data.dm *.extC;
}

DataFormat format_B {
Pattern = *.extB;
Preferred_Editor = exampleEditor;
Default_Editor = exampleEditor;
dfII_ViewType = format_B;
Co_Managed = master.tag data.dm;
}

deRegApp code for Example:

when(!member("format_A" deGetAllViewTypes()) 
deRegApp(
?appName "exampleEditor"
?enableTrigger 'EnableTrigger
?dataTrigger 'DataTrigger
?viewType "format_A"
?appTrigger 'ViewAppTrigger
?widgetType "graphics"
)
)
when(!member("format_B" deGetAllViewTypes()) 
deRegApp(
?appName "exampleEditor"
?enableTrigger 'EnableTrigger
?dataTrigger 'DataTrigger
?viewType "notebook"
?appTrigger 'ViewAppTrigger
?widgetType "graphics"
)
)

Tool exampleEditor {  }

Regards,

Curtis