Create router map doesnt work well with properties

[fa1k3n]

If you have a class containing properties the getters are called when the ocpp library is building its route map since it iterates att the attributes in the object

in router.py

 for attr_name in dir(obj):
       attrib = getattr(obj, attr_name)    

The problem is with the getattr call, if this is a property it will then actually call the getter method, which in most cases is unwanted.

One solution that I have found is to have a global list in router.py that contains all the routables. The on and after decorators can then append the method name to this list. Then during the call to create router map instead of iterating the object attributes this list can be iterated

[OrangeTux]

Hello. thanks for the report. I tried reproduce the problem as you described in a minimal example, but I failed. Can you show some code that show the problem?

[fa1k3n]

Sure , it should be sufficient to add to the basic example , in the ChargePoint class @Property def foo(self): raise Exception(“this will be thrown when router is set up”) But I need to unpatch my fixed version of the library to verify that. Will test tomorrow and get back with minimal example

…

19 okt. 2020 kl. 21:01 skrev Auke Willem Oosterhoff ***@***.***>:  Hello. thanks for the report. I tried reproduce the problem as you described in a minimal example, but I failed. Can you show some code that show the problem? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[fa1k3n]

Here is a minimal unittest that will provoke the error and thus fail

import unittest                                                                                                                               
from ocpp.v20 import ChargePoint as cp                                                                                                        
                                                                                                                                          
class ChargePoint(cp):                                                                                                                        
    @property                                                                                                                                 
    def foo(self):                                                                                                                            
        raise Exception("this will be raised")                                                                                                     
                                                                                                                                          
class TestChargePoint(unittest.TestCase):                                                                                                     
    def test_getters_should_not_be_called_during_routemap_setup(self):                                                                        
        try:                                                                                                                                  
            ChargePoint("blah", None)                                                                                                         
        except Exception as e:                                                                                                                
            self.assertEqual(str(e), "this will be raised”)                                                                                        
            self.fail("Getter was called during ChargePoint creation")                                                                        
        self.assertTrue(True)                                                                                                                 
                                                                                                                                          
if __name__ == '__main__':                                                                                                                    
    unittest.main()

[OrangeTux]

Thanks for the code. I was able to reproduce the error.

[fa1k3n]

Thanks for the code. I was able to reproduce the error.

excellent, do you want me to do a PR for my solution?

[OrangeTux]

Sure! It would be great.

[fa1k3n]

just did it, all tests passed locally, CI is running right now