How to run a function up on activating (Clicking on ) a python result file. for instance OnActivate

I have written a code that updates the tabular data of a python result. The tabular data are populated from the information in the properties section of the python result file so I need it to execute after the properties are loaded.
At the moment I have a property that on_property_change, performs the task.
Is there a way to have this module execute upon the user activating the python result form by clicking on it in the tree?