[Controller Hooks] Difference between on_update and on_change

scdanieli · April 18, 2020, 5:01pm

I was wondering, what’s the difference between on_update and on_change regarding Controller Hooks.

Cheers!

stephenBDT · April 1, 2021, 10:36am

This is ranking high on google.
Can someone please shortly elaborate on this?
Thanks

stephen1 · April 12, 2021, 8:05am

Can someone please explain this?!

mwatkins · June 18, 2021, 5:30pm

Taking a look at the code, it appears that the difference comes into play around the submissions feature. The on_update hook is only triggered when the form is saved or submitted. The on_change hook is fired in those instances but is also fired when the document is cancelled or when it is updated after submit.

github.com

frappe/frappe/blob/513871d8f99dfdd1ad4ad7ea56f51634f72740af/frappe/model/document.py#L990-L1009


      
          		if self._action=="save":
          			self.run_method("on_update")
          		elif self._action=="submit":
          			self.run_method("on_update")
          			self.run_method("on_submit")
          		elif self._action=="cancel":
          			self.run_method("on_cancel")
          			self.check_no_back_links_exist()
          		elif self._action=="update_after_submit":
          			self.run_method("on_update_after_submit")
          
          

          
		self.clear_cache()
          		self.notify_update()
          
          
		update_global_search(self)
          
          
		self.save_version()
          
          
		self.run_method('on_change')

mwatkins · June 22, 2021, 7:46pm

on_change also fires when you delete a document.