Are hooks correctly saving assigned priority?

[aGitForEveryone]

From _hooks.py we see that hook decorators, e.g. @hooks.layout, are actually just wrappers around self.add_hook. Looking at self.add_hook and how it handles input parameter priority, how is the value given to priority passed down to the hook?

It is only used in the check if not priority, which fails if a non-zero value is given and is otherwise not used. The value given to _Hook, is priority=p, and p=0 is set.

Is this a bug or am I misunderstanding how hooks are later used/called?

See: https://github.com/plotly/dash/blob/v3.0.0rc1/dash/_hooks.py#L58-L81

[T4rk1n]

It is only used in the check if not priority, which fails if a non-zero value is given and is otherwise not used. The value given to _Hook, is priority=p, and p=0 is set.

That is just to set the priority to be less than last one submitted if not supplied, the hooks are then sorted later based on priority.

dash/dash/_hooks.py

Line 80 in b711247

self._ns[hook] = sorted(hks, reverse=True, key=lambda h: h.priority)

[aGitForEveryone]

But where does the priority that the user sets enter the hooks? The actual Hook is created as:

hks.append(_Hook(func, priority=p, data=data))

Where the priority of the hook is set as p and p = 0. The priority that the user sets is never used.

[T4rk1n]

Your right, the test here may be flawed:

dash/tests/integration/test_hooks.py

Line 102 in e77aafb

def test_hook006_priority_final(hook_cleanup, dash_duo):

Thanks for bringing this up, I'll fix this for RC2