Reflection on constructors.. How to access method of new variant?

[jondecker76 Participant]

I’m finally to the point where I can create new class instances using reflection…

However, I’m stuck, as now I can’t do anything with the new variant.  The variant.DyanmicType property does indeed report that I’ve created the class that I want.  However, I can’t access anything within the class from this point, as I then get an error about the variant not having the property or method…

Simple sample:

Monkey

Class A Method Test() Print "Success!" End End</p> <p>Class B Field a:Variant</p> <p>End</p> <p>Function Main() Local instance:=New B instance.a=New A instance.a.Test() ' Fails, because Value of type 'monkey.types.Variant' has no member named 'Test' End

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Class A Method Test() Print "Success!" End End   Class B Field a:Variant End   Function Main() Local instance:=New B instance.a=New A instance.a.Test() ' Fails, because  Value of type 'monkey.types.Variant' has no member named 'Test' End

[Danilo Participant]

You can store any Object in a Variant, and because of that you have to tell Monkey2 what it is.

With casting you can tell Monkey2 that instance.a is an instance of class A:

Monkey

[crayon-5c4966e1f17e0068666388 inline="true" ] Class A Method Test() Print "Success!" End End</p> <p>Class B Field a:Variant</p> <p>End</p> <p>Function Main() Local instance:=New B instance.a=New A Cast<A>(instance.a).Test() End

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[crayon-5c4966e1f17e0068666388 inline="true" ] Class A Method Test() Print "Success!" End End   Class B Field a:Variant   End   Function Main() Local instance:=New B instance.a=New A Cast<A>(instance.a).Test() End

[/crayon]

Using that way you could use different classes that implement the same methods:

Monkey

[crayon-5c4966e1f17e6071418242 inline="true" ] Interface ITest Method Test() End</p> <p>Class A Implements ITest Method Test() Print "Success A!" End End</p> <p>Class B Implements ITest Method Test() Print "Success B!" End End</p> <p>Class C Implements ITest Method Test() Print "Success C!" End End</p> <p>Class TheClass Field a:Variant End</p> <p>Function Main() Local instance:=New TheClass</p> <p> instance.a=New A Cast<ITest>(instance.a).Test() instance.a=New B Cast<ITest>(instance.a).Test() instance.a=New C Cast<ITest>(instance.a).Test()</p> <p>End

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[crayon-5c4966e1f17e6071418242 inline="true" ] Interface ITest     Method Test() End   Class A Implements ITest Method Test() Print "Success A!" End End   Class B Implements ITest Method Test() Print "Success B!" End End   Class C Implements ITest Method Test() Print "Success C!" End End   Class TheClass     Field a:Variant End Function Main()     Local instance:=New TheClass       instance.a=New A     Cast<ITest>(instance.a).Test()     instance.a=New B     Cast<ITest>(instance.a).Test()     instance.a=New C     Cast<ITest>(instance.a).Test()   End

[/crayon]

[jondecker76 Participant]

Thanks for the reply.

 

I was afraid of that.  It seems like there is no way to get a true object from the reflection system and have it usable as a normal object (without heaping up piles of GetType..GetDecl..Invoke..Cast.. and making the code overly complex)

I’m trying to build an XML parser that builds objects out of “skeleton” classes from the XML data.  But I wanted to do so without special cases and Casts, as there are literally hundreds of skeleton classes.  I just can’t find a way to build a true object from it’s name:String in monkey2.  I’m guessing that I’m just going to have to bite the bullet and write a custom loader for each and every one of the hundreds of object types.  Bummer

 

For example, I just need to make a function that:

instance:=ObjectFromName(“class_name”)

[Danilo Participant]

Could you use the following?
instance:=ObjectFromName<class_name>(“class_name”)

Creating an object just from a string, without telling Monkey2 what it is, is probably very hard if possible at all.

[jondecker76 Participant]

I’m going to take a hybrid approach – I’ll have to make routines to match the appropriate skeleton class to the XMLString – but then I’ll use reflection to fill in the fields in the class.  At least I’m hoping this method will work

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