Create Subclass from Super class?

General
1

I have a Class that has over 150 subclasses (implementing XML spec), is there a way to do the equivalent of “Var myItem As MySuperclass = New SpecificSubclass” generically without hardcoding all the classnames in a long ElseIf or Select Case? My goal is to keep a list of XML Property names and the corresponding specific Subclass in a Xojo.Core.Dictionary (or something similar)

2

You can write an app to write Xojo classes as text files and drop them in the class.

3

I may not have explained what I need clearly enough. I’m looking to replace a Static Method’s 150+ option long “If theName = exactSpecifier Then Var myItem As MySuperclass = New SpecificSubclass ElseIf theName = AnotherSpecifier . . .” (or the equivalent Select Case) with a Generic "Var myItem As MySuperclass = New " I tried “dict(“specifier”) = ExactSubclassname” then “Var myItem As MySuperclass = New dict(“specifier”).Value(constructor parms)” but it didn’t work.

4

Okay, use introspection to get class by name and then call constructor.

5

I looked at the docs for Introspection but couldn’t see what you’re referring to. Can you please post a simple example?

6

You get the class, get the ConstructorInfo objects, pick one and call Invoke on it.

see
https://documentation.xojo.com/api/language/const.htmlructorInfo

7

All the docs only show the example of a parameterless constructor call but the constructor I need to call has one parameter. Could you post an example of calling a constructor with a single parameters please? In my actual code, the parameter is an object.

I just realized that the class MAY HAVE two constructors as the Super class has a Private no-arg constructor to stop it from being instantiated. In this case, will it automatically call the correct constructor if I pass the parameter? If not, how do I make sure I’m calling the proper constructor?

8

Invoke takes optionally an array of variants for parameters, so pick the right constructor and pass the required parameters.

9

Where can I put my test Project so you or someone else can explain the “expect Variant() but this is Window1.Window1” error message?

10

Github GitHub

DropBox DropBox

11

Uploaded “Introspection Test” to https://www.dropbox.com/s/o8xunilf80hp2f7/Introspction%20Test.xojo_binary_project?dl=0

Any and all assistance welcome.

12

[quote=493260:@Bryan Dunphy]Uploaded “Introspection Test” to https://www.dropbox.com/s/o8xunilf80hp2f7/Introspction%20Test.xojo_binary_project?dl=0

Any and all assistance welcome.[/quote]
you are welcome