Hi Joao,
Just like 'nodes' & 'children' operation, You have to implement several other methods,
'obj' - To create, update, delete & properties for External Tables
Ref: ../foreign_tables/__init__.py: 193
Which will call associated methods, def create(..), def update(...), def delete(...) & def properties(...)
'sql' - Displays reversed engineered sql on SQL panel
Which will call to method def sql(...) method
'msql' - Displays reversed engineered sql on Create/Properties dialogWhich will call to method def msql(...) method
'stats' -Displays object statistics sql on Statistics panelWhich will call to method def statistics(...) method
'dependency' - Displays object dependencies on Dependencies panelWhich will call to method def dependencies(...) method
'dependent' - Displays object dependents on SQL panelWhich will call to method def dependents(...) method
Hope that helps.