Executing javascript code during entity creation?

[tothewine]

I am trying to read a flag from the url before the creation form of an entity is rendered. In my case it's a Call and the url is http://example.com/#Call/create?flag=1
Is there a "setup" function where i can add code to check the URL and act on the view&model if the flag is found?

[tanya]

entity creation (in entity manager) or record of entity creation?

[tothewine]

Yeah sorry, it was unclear. I meant when the record is being created by a user.