Method xxxx As UDT

[Scott Slater]

I see in the docs that a method can return a user defined type. I have been experimenting with this, but can't quite figure out how to access the individual elements of the UDT. Here's an example:

Type TestType
   elem1 as long
   elem2 as long
   elem3 as bit * 1 in Byte
   elem4 as bit * 1
   elem5 as bit * 6
   elem6 as asciiz * 20
End Type
 
 ...
   Method TestMethod As TestType
      Method = TestTypeVar
   End Method
...
   Property Get TestProp As TestType
      Property = TestTypeVar
   End Property
...

In the above example I would expect to access elem6 in the type by calling my object like MyObj.TestMethod.elem6, but this doesn't seem to work. Can someone tell me the correct way to read back UDT data embedded in an object.

My goal is to have this as read-only data so I first tried the Property, but it doesn't work using the Method either. At least the way that I was trying

I was trying ObjectName.Method/Property.UDT_Element

I am new at this object stuff, so forgive me... But I am beginning to see great potential here!

[colin glenn]

You would have to have a PROPERTY GET for each element of the UDT, at least that's the way I read it.

[Scott Slater]

Then you wouldn't really need to TYPE the property as a UDT, just the element's type would suffice in that case.

[Scott Slater]

I can assign the Method's return using LSet so it must really be returning the type as a string. If I were to use another object instead of the UDT, could it be called in the manner that I was trying above?

The reason I was trying a UDT is that I want to return Bool values so I was going to use BITs to do this. I know could just use a LONG and the bit function, but having readable names makes the code easier to look at. I suppose that I could just use BYTE vars instead, but I think something like;

If Employee.Rights.CanPrint Then... is more readable than

If Flag(Employee.Rights, 2) Then...

I just saw this in the Docs and thought I could access the data directly at the second level.

Methods may be declared (using AS type...) to return a string, any of the numeric types, a specific class of object variable (AS MyClass), a Variant, or a user defined Type.

[colin glenn]

What you should do then is create a property:

PROPERTY GET EmployeeRights() AS LONG
    PROPERTY = IIF( ... , %TRUE, %FALSE)
END PROPERTY

And that provides your flag in addition to the encapsulation of the data, the end result is that your code don't CARE how the object stores the data, it just knows HOW to get the desired results from the object.

[Scott Slater]

Here's a sample of what I was trying to do. I need the rights to be all together accessible as "whole" as well as the parts. That's why I wanted to use a UDT or another object.

#Compile Exe
#Dim All
 
Type EmployeeRights
   CanPrint As Bit * 1 In Byte
   CanDo_A  As Bit * 1
   CanDo_B  As Bit * 1
   CanDo_C  As Bit * 1
   CanDo_D  As Bit * 1
   CanDo_E  As Bit * 1
   CanDo_F  As Bit * 1
   CanDo_G  As Bit * 1
End Type
 
Class EmployeeClass
   Instance tSecurity  As EmployeeRights
   
   Class Method Create
      tSecurity.CanPrint = 1
      tSecurity.CanDo_A = 0
      tSecurity.CanDo_B = 1
      tSecurity.CanDo_C = 0
      tSecurity.CanDo_D = 1
      tSecurity.CanDo_E = 0
      tSecurity.CanDo_F = 1
      tSecurity.CanDo_G = 0
   End Method
   
   Interface EmployeeInterface
      Inherit IUnknown
      
      Property Get Rights As EmployeeRights
         Property = tSecurity
      End Property
   End Interface
 
End Class
 
Function PBMain () As Long
 
    Local Employee As EmployeeInterface
    
    Employee = Class "EmployeeClass"
    
    ? Format$( Employee.Rights.CanPrint )   ' <--  This is where the problem is accessing the UDT
    
    Employee = Nothing
 
End Function

*Thanks for your help on this Colin.

I guess I will look into returning an Object instead of a UDT.

[Scott Slater]

Update:

I was able to accomplish what I wanted using another object instead of the UDT. See "What is a Compound Object Reference?" in the docs. That is exactly what I wanted to do. So now code looks like:

#Compile Exe
#Dim All
 
Class RightsClass
   Instance AllRights As Dword
   
   Class Method Create
      AllRights = 5641
   End Method
   
   Interface RightsInterface
      Inherit IUnknown
      
      Property Get CanPrint As Byte
         Property = Bit(AllRights,0)
      End Property
 
      Property Get CanHaveFun As Byte
         Property = Bit(AllRights,1)
      End Property
   End Interface
End Class
 
Class EmployeeClass
   Instance oSecurity  As RightsInterface
   
   Class Method Create
      oSecurity = Class "RightsClass"
   End Method
   
   Interface EmployeeInterface
      Inherit IUnknown
      
      Method Rights As RightsInterface
         Method = oSecurity
      End Method
   End Interface
 
End Class
 
Function PBMain () As Long
 
    Local Employee As EmployeeInterface
    
    Employee = Class "EmployeeClass"
    
    ? Format$( Employee.Rights.CanPrint )   ' <--  Using Object instead of UDT
    
    Employee = Nothing
 
End Function