VBScript Reference Manual for InduSoft Web Studio

InduSoft Web Studio VBScript Reference Manual
Execute
Description Executes one or more specified statements in the local namespace.
Usage Execute statement
Arguments The required statement argument is a string expression containing one or more statements for
execution. Include multiple statements in the statement argument, using colons or embedded line
breaks to separate them.
Remarks In VBScript, x = y can be interpreted two ways. The first is as an assignment statement, where
the value of y is assigned to x. The second interpretation is as an expression that tests if x and y
have the same value. If they do, result is True; if they are not, result is False. The Execute
statement always uses the first interpretation, whereas the Eval method always uses the second.
The context in which the Execute statement is invoked determines what objects and variables
are available to the code being run. In-scope objects and variables are available to code running
in an Execute statement. However, it is important to understand that if you execute code that
creates a procedure, that procedure does not inherit the scope of the procedure in which it
occurred.
Like any procedure, the new procedure's scope is global, and it inherits everything in the global
scope. Unlike any other procedure, its context is not global scope, so it can only be executed in
the context of the procedure where the Execute statement occurred. However, if the same
Execute statement is invoked outside of a procedure (i.e., in global scope), not only does it
inherit everything in global scope, but it can also be called from anywhere, since its context is
global. The following example illustrates this behavior:
Example Sub Proc1 'Declare procedure.
Dim X 'Declare X in local scope.
X = "Local" 'Assign local X a value.
Execute "Sub Proc2: MsgBox X: End Sub" ‘Create a subroutine. Proc2 is local in scope
MsgBox Eval("X") 'Print local X.
Proc2 'Invoke Proc2 in Proc1's scope.
End Sub
Rem Main Program
Dim X, s 'Declare X in global scope.
X = "Global" 'Assign global X a value.
Proc2 ‘Error - Proc2 is unavailable outside Proc1.
Proc1 'Invokes Proc1.
s = “ Main Program”
Execute (“X = X & s”) ‘Concatenates strings
Execute "Sub Proc2: MsgBox X: End Sub"
Proc2 'Succeeds as Proc2 is now available globally.
The result when executing the above code is:
Local From MsgBox Eval(“X”) in Proc1
Global From Proc2 statement in Proc1
Global Main Program From Proc2 statement in Main program
The following example shows how the Execute statement can be rewritten so you don't have to
enclose the entire procedure in the quotation marks:
S = "Sub Proc2" & vbCrLf
S = S & " Print X" & vbCrLf
S = S & "End Sub"
Execute S
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