How To Use Script Control Modules and Procedures Collections (184745)

MORE INFORMATION

The Microsoft Script control includes features that allow the host application to segment scripts into different modules. The default module, "Global", is always present. Different modules may contain procedures of the same name (that is, procedure names have module scope).

The Microsoft Script control also includes procedure properties that allow the host application to dynamically determine whether the procedure is a Function or a Sub as well as the number of arguments it expects. This allows the host application to prompt the user for the correct number of parameter values.

The Modules property of the Script control is an object that contains a collection of module objects. It has the following properties and methods:

• Count: The number of modules.
• Item(x): Returns a single Module object.
• Add name: Adds a blank module with the given name.

The Module Object has the following properties and methods:

• Name: The module name.
• Procedures: The Procedures object.
• AddCode code: Adds the code to the module.
• Run name, args: Runs the named procedure.

The Procedures object contains a collection of Procedure objects. It has the following properties and methods:

• Count: The number of procedures in the module.
• Item(x): Returns a single Procedure object.

The Procedure object has the following properties and methods:

• Name: The procedure name.
• HasReturnValue: Indicates whether the procedure is a Sub or a Function.
• NumArgs: The number of arguments the procedure requires.

NOTE: Not all properties and methods of the listed objects are given, just those relevant to this article.

The following example provides an interactive program that illustrates how to use these properties and methods:

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.

Example

1. In Visual Basic, create a new project (Form1 is created by default).
2. Click Components on the Project menu, and then select the "Microsoft Script Control 1.0" check box.
3. Add the Script control (ScriptControl1), a text box (Text1), three command buttons (Command1, Command2, Command3), and two list boxes (List1, List2) to Form1. Set the MultiLine property of the text box to TRUE. Size the text box to accommodate 5 lines of 30 characters.
4. Add the following code to Form1:

         Private Sub Command1_Click()
           ScriptControl1.Modules.Add Text1.Text
           Form_Activate
         End Sub
   
         Private Sub Command2_Click()
           ScriptControl1.Modules(List1).AddCode Text1.Text
           List1_Click
         End Sub
   
         Private Sub Command3_Click()
         Dim RetVal As Variant, m As Variant
           Set m = ScriptControl1.Modules(List1.Text)
           With m.Procedures(List2.Text)
             Select Case .NumArgs
               Case 0
                 RetVal = m.Run(List2.Text)
               Case 1
                 RetVal = m.Run(List2.Text, 5)
               Case 2
                 RetVal = m.Run(List2.Text, 4, 23)
               Case Else
                 MsgBox "Procedure has too many arguments"
             End Select
             If .HasReturnValue Then
               MsgBox List2.Text & " returned: " & RetVal
             End If
           End With
         End Sub
   
         Private Sub Form_Activate()
         Dim m As Variant
           List1.Clear
           With SCriptControl1
             .Language = "VBScript"
             .AllowUI = True
             For Each m In .Modules
               List1.AddItem m.Name
             Next m
           End With
         End Sub
   
         Private Sub Form_Load()
           Command1.Caption = "Add Module"
           Command2.Caption = "Add Code"
           Command3.Caption = "Run Procedure"
         End Sub
   
         Private Sub List1_Click()
         Dim m As String, p As Variant
           m = List1
           List2.Clear
           If m = "" Then Exit Sub
           For Each p In ScriptControl1.Modules(m).Procedures
             List2.AddItem p.Name
           Next p
         End Sub
   
         Private Sub List2_Click()
         Dim m As String, p As String, r As Boolean, a As Long
           m = List1
           p = List2
           With ScriptControl1.Modules(m).Procedures(p)
             r = .HasReturnValue
             a = .NumArgs
           End With
           MsgBox m & "." & p & " has " & IIf(r, "a", "no") & _
                  " return value and " & a & " arguments"
         End Sub
   						

5. Run Form1.
6. Create a new module by typing the following in the text box and clicking Add Module:

         Mod2
   
   						

7. Type the following script in the text box:

         Function Calc(X)
           Calc = X * 2
         End Function
   						

8. Select Global in List1, and then click Add Code to add to the global module.
9. Type the following script into the text box:

         Function Calc(X, Y)
           Calc = X * Y
         End Function
   
         Sub Test()
           MsgBox "The Test Sub in Module Mod2"
         End Sub
   						

10. Select Mod2 in List1, and then click Add Code to add to the global module.
11. Click on the various modules and procedures. When you select the procedure a message box appears, indicating whether the procedure has a return value as well as the number of arguments it takes.
12. After selecting a procedure, click Run Procedure to run it. The code determines the number of arguments to use and you will see varying message boxes with the results.

NOTE:

• The global module name might not always be "Global" depending on control version or localization. Use the GlobalName constant instead of hard- coding the word "Global".
• There is no method to remove individual modules or procedures. You have to use the .Clear method of the script control to erase all code. You can overwrite a procedure by using the .AddCode method with a procedure of the same name.

   HasReturnValue Property
   NumArgs Property
   AddCode Method
   Run Method
   Modules Collection
   Procedures Collection