I am adding a URL handler to a Flask application using add_url_rule. It requires a function as a handler (not a method). However, for proper encapsulation, my intended function is a bound method that uses the self variable. Is there any way I can somehow make Flask see my function: def action(self, param) as def action(param) ?
class A():
def __init__(self):
self._localvar = 5
self._flask = Flask("testapp")
def add_rules(self):
self._flask.add_url_rule("/","root",????)
def action(self, value):
print("The value is {}".format(self._localvar))
def run(self):
self._flask.run()
app = A()
app.add_rules()
app.run()
what I want to do is replace ???? with app.action, a bound method. However, add_url_rule expects a function. I tried app.action.__func__ and app.action.im_func which are function pointers. However, the function signature is still going to require self and will give me a runtime error.
My current solution is to have some loose functions in my module and have app just use them directly, but it just seems that there has to be a cleaner way since the handlers are really tightly coupled to the app object and I don't want them floating around outside of it.
I Think I finally found a way to do this (i.e. keep the action method bound inside my class and have a function-like reference to it when needed). I used a function inside a method:
class A():
def __init__(self):
self._localvar = 5
self._flask = Flask("testapp")
def add_rules(self):
self._flask.add_url_rule("/","root",self.action_as_func())
def action(self, value):
print("The value is {}".format(self._localvar))
def action_as_func(self):
def inner_action(value):
self.action(value)
return inner_action
def run(self):
self._flask.run()
app = A()
app.add_rules()
app.run()
Any comments on whether there is something wrong with this ? The function can access self. Kinda sneaky :)