[Question] List property names of a DWSCript Class

[Toky Olivier Razanakotonarivo]

Hello,

In JS, one can list all property names of an object (for example: https://www.w3docs.com/snippets/javascript/how-to-list-the-properties-of-a-javascript-object.html) but in DWScript, is there any method to list all properties? I’m working mostly with the JSCodegen. When the output js code is not optimized, may be I can list procedure/function but not property names, but when the code is optimized for size, I cannot find the procudure/function names, property names of the Class.

Thank you,

[Eric Grange]

Hi,

When optimizing for size, what’s not marked as “published” can be renamed to a shorter name or eliminated completely by the linker. Is that what you are referring to ?

[Toky Olivier Razanakotonarivo]

Hi Eric,

I would like to be able do this in DWS (in JSCodeGen or DWS script), I don’t know if it’s related to RTTI as I never used it :

type
  TMyObject = class
  private
    FProp1, FProp2: String;
  published
    property Prop1: String read (FProp1);
    property Prop2: String read (FProp2) write (FProp2);
  end;

  begin
    var obj: TMyObject := TMyObject.Create();
    obj.Prop1 := 'Test1';
    obj.Prop2 := 'Test2';

    write(obj.PublishedProperties.Count); //Prints 2 (or more if it's inherited from another classes)
    write(obj.PublishedProperties['Prop1'].Value); //Prints Test1
    write(obj.PublishedProperties['Prop2'].Value); //Prints Test2
    write(obj.PublishedProperties['Prop1'].ReadOnly); //Prints True
    write(obj.PublishedProperties.IndexOf('Prop3')); //Prints False
    //etc...

    obj.Destroy();
  end.

I know, every one may not need this but as in JS we can use them, I think it’s better to have that in DWS. I see that classes in DWS are not exactly like JS classes so I cannot do this even with asm blocks:

asm
  var keys=Object.keys(@obj); //I won't have Prop1 and Prop2 in keys
end;

I have one need of it and that’s why I ask the question.

Thank you.

[Eric Grange]

Yes, this is covered by RTTI, which needs to be enabled in the compile option, and you need to disable optimization for size.

There are code examples in the FunctionsRTTI test folder. There is no high-level API for the RTTI right now, it’s a big array with all the RTTI data

[Toky Olivier Razanakotonarivo]

Thank you Eric. It’s really what I need. But I tested with the Live Scripting Demo, none of the code examples can be compiled. Can you check please?

‌

[Eric Grange]

Looks like LiveDemo is missing a dependency to dwsRTTIFunctions

[Eric Grange]

Fixed #245 missing dependencies in LiveScripting demo

→ <<cset 56e1ab389936>>