getproperty incompatible with ParentScope and DelayParentScope

[jamesjscully]

Accessing a parameter or variable whos scope was defined with ParentScope() errors.

using ModelingToolkit, Test
@parameters t a
p = [
     ParentScope(a)
]

level0 = ODESystem(Equation[], t, [], p; name = :level0)
level1 = ODESystem(Equation[], t, [], []; name = :level1) ∘ level0

ModelingToolkit.getname(parameters(level1)[1]) # a

level1.a # this errors, claiming a is not defined

[jamesjscully]

I will submit a PR for this, but there is a design decisions that I have a question

Should you be able to access variables that have been parentscoped before they reach their localscope has been created? Following the example above:

level0.a is defined, but 'a' really belongs in level1. My inclination is to have both defined because it could be convenient for the user to access the parameters that way, and I don't see any harm in it.

Also I was implementing this with a depth first search through the hierarchy of subsystems, but the other option would be to pass additional metadata to the parent system.

[YingboMa]

I would be inclined to cache the information during construction so that sys.a can be fast even for large and deeply nested models.

[ChrisRackauckas]

Fixed in the v9 with the enforced complete.