Param.depends shorthand for “depends on all params”

[poplarShift]

I frequently end up adding/removing parameters to a parameterized Class, either by hand or by using them as parent classes later on. That means going through the entire class and updating all @param.depends(...) decorators, which quickly gets confusing especially when I have separate mixin classes for visualizations etc.

This could be solved by a shorthand for “this function depends on all params this class or its child classes might have”.

E.g. something like

@param.depends(all_params=True)

or even

@param.depends()

(Following up on https://discourse.holoviz.org/t/param-depends-shorthand-for-depends-on-all-params/270)

[jbednar]

This is a bit tricky. The assumption is already that all methods depend on all parameters by default. I.e., unless you specify otherwise, any method could access any parameter, and the logic is already set up to assume that. @param.depends() in fact declares the opposite, that this method does not depend on any parameters. I don't see how this could be changed now; the semantics of dependencies would cause lots of problems if they were altered at this point.

But for practical reasons we have not assumed any access of the subobject parameters, so yes, in order to depend on all subobject parameters we'd need some way to express that the dependencies are nested in that way.

[poplarShift]

I see now that this is trickier than I initially thought; what you say makes sense to me. However, I think I've come across cases where declaring @depends() was different from @depends(*all_my_params) in terms of the number of times a given subroutine was called by panel upon triggering a change in a widget, but I'd have to find those code snippets again.

[jbednar]

To clarify, @depends() means "this method does not depend on any parameters", while @depends(*all_my_params) means "this method depends on all my parameters", so there should be a difference there.

[poplarShift]

I see, thanks a lot.

[tonyfast]

The wishlist item is to have an expression that depends recursively on all sub objects.