How To Call Functions Using the Script Control

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This article was previously published under Q184740

SUMMARY

This article provides sample code for the Script control that demonstrates various methods of calling script functions from Visual Basic.

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IMPORTANT: Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures.

The Script control can host VBScript, JavaScript, and any other compliant scripting language, so your users can script your application in a similar manner to using VBScript or JavaScript to provide additional functionality for Web pages.

The following article in the Microsoft Knowledge Base describes how to obtain the Script control:

184739 (http://support.microsoft.com/kb/184739/EN-US/ ) : INFO: Where to Obtain the Script Control

The Script control provides four methods for calling Sub and Function script routines:

Eval: Evaluates a text expression.
Run: Runs a named Sub or Function.
Execute: Executes a script statement.
As a method of a Module object.

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Eval

The calling convention is:

  Result = ScriptControl.Eval("some text expression")

You can use this method to call both intrinsic script functions, as well as user functions. Function arguments are passed as literal values in the expression text and can be either hard-coded or concatenated from a variable.

NOTE: This method cannot be used to call Subroutines.

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Run

The calling convention is:

  Result = ScriptControl.Run("Name", arg1, arg2, ... argn)

You can use this method to call Subroutines, in which case the Result returned is empty and you can use the alternate calling convention to ignore the return result:

  ScriptControl.Run "Name", arg1, arg2, ... argn

NOTE: Name is the name of the Sub or Function, and arg1 ... argn are optional depending on the Sub or Function in question.

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Execute

The calling convention is:

  ScriptControl.Execute "statement text"

This method allows you to call any intrinsic statement or Sub routine. You can also use it to call functions, but the return result is dropped.

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Module Method

The calling convention is:

   Result = ScriptControl.Modules(modulename).functionname(arg1, arg2, ...)
   ScriptControl.Modules(modulename).subname arg1, arg2, ...

The default module is given in the GlobalModule constant, such as:

   Result = ScriptControl.Modules(GlobalModule).MyFunction(5)
   ScriptControl.Modules(GlobalModule).MySub 5, "A"

For more information on ScriptControl modules, please see the following article in the Microsoft Knowledge Base:

184745 (http://support.microsoft.com/kb/184745/EN-US/ ) : How To Use Script Control Modules and Procedures Collections

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Example

In Visual Basic, create a new project. Form1 is created by default.
Click Components on the Project menu, and then select the "Microsoft Script Control 1.0" check box.
Add the Script control (ScriptControl1), a text box (Text1), and a command button (Command1) to a form. Set the MultiLine property of the text box to True.

Add the following code to Form1:

      Private Sub Command1_Click()
        With ScriptControl1
          ' Set script language (VBScript is the default).
          .Language = "VBScript"
          ' Set UI interaction (TRUE is the default).
          .AllowUI = True
          ' Copy the script to the control.
          .AddCode Text1.Text
          ' Demonstrate the Eval method.
          Debug.Print .Eval("AddTwo(5,7)")
          ' Demonstrate the Run method both with and without return values.
          .Run "Hello", "Jane Doe"
          Debug.Print .Run("Hello", "James Smith")
          .Run "AddTwo", 4, 6
          Debug.Print .Run("AddTwo", 7, 8)
          ' Demonstrate the ExecuteStatement method.
          .ExecuteStatement "Hello ""Sue Smith"""
          .ExecuteStatement "AddTwo 9,18"
          .ExecuteStatement "MsgBox CStr(AddTwo(3,8))"
          .Modules(GlobalModule).Hello "Jane Doe"
          Dim oMod As Object
          Set oMod = .Modules(GlobalModule)
          Debug.Print oMod.AddTwo 12, 24
          Set oMod = Nothing
        End With
      End Sub

Run Form1, and open the Debug window.

Type the following script in the text box:

      Sub Hello(YourName)
        MsgBox "Hello " & YourName
      End Sub

      Function AddTwo(X1, X2)
        AddTwo = X1 + X2
      End Function

Click the CommandButton.

NOTE: The following two statements do not produce an output because the function return is lost and the code does not output the result through any other means, such as a global variable or message box:
.Run "AddTwo", 4, 6 .ExecuteStatement "AddTwo 9,18"

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