ObserverFiringMultipleTimes.rb

module Test

    unless file_loaded?(__FILE__)

        SKETCHUP_CONSOLE.show()

        # We'll count how many time the observer is fired when we open/create a model
        @@counter = 0

        def self.counter
            @@counter
        end

        def self.counter=(x)
            @@counter = x
        end


        # Custom definitions observer

        class CustomDefinitionsObserver < Sketchup::DefinitionsObserver

            def onComponentAdded(definitions, definition)

                Test.counter += 1

                puts "definition #{definition.entityID} added to model #{definition.model.definitions.entityID}: #{Test.counter} times"
            end
        end

        puts "attaching observer to the startup model #{Sketchup.active_model.definitions.entityID}"
        Sketchup.active_model.definitions.add_observer(CustomDefinitionsObserver.new())


        # Custom app observer to attach a definitions observer to each new model

        class CustomAppObserver < Sketchup::AppObserver

            def onOpenModel(model)

                puts ""
                puts "opening model #{model.definitions.entityID}"
                puts "attaching observer to model #{model.definitions.entityID}"

                Test.counter = 0

                model.definitions.add_observer(CustomDefinitionsObserver.new())
            end

            def onNewModel(model)

                puts ""
                puts "new model #{model.definitions.entityID}"
                puts "attaching observer to model #{model.definitions.entityID}"

                Test.counter = 0

                model.definitions.add_observer(CustomDefinitionsObserver.new())
            end

        end

        Sketchup.add_observer(CustomAppObserver.new())

    end
end