Methods are implemented as functions or subroutines in your Windows® Script Component file.
Procedures
To expose a method
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Create a <public> element as a child of the <component> element.
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In the <public> element, include a <method> element. The method element can optionally include one or more <parameter> elements to define the method's parameters.
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Write a procedure in any scripting language to implement the function. Place the procedure in a <script> element outside the <implements> element but within the <component> element. Be sure the function name matches the functionName, or if you did not specify a functionName, the methodName name you specified in the <method> element.
For example, the following example shows a fragment from a script component file with two methods, factorial and getRandomNumber.
Note A CDATA section is required to make the script in the <script> element opaque. For details, see Script Component Files and XML Conformance.
Copy Code<public> <method name="factorial"/> <method name="random" internalName="getRandomNumber"> <parameter name="upperBound"/> <parameter name="seed"/> </method> </public> <script language="VBScript"> Function factorial(n) <![CDATA[ If isNumeric(n) Then If n <= 1 Then factorial = 1 Else factorial = n*factorial(n-1) End If Else factorial = -2 ' Error code. End If End Function Function getRandomNumber(upperBound, seed) getRandomNumber = Cint(upperBound * Rnd(seed) + 1) End Function ]]> </script>
You can specify a default method for a script component so the host application can invoke the method without explicitly calling it. For example, if you have exposed a method called factorial and marked it as the default, you can call it in the following ways in Visual Basic:
| Copy Code | |
|---|---|
Set component = CreateObject("component.MyComponent")
n = component.factorial(4) ' Calls factorial method explicitly.
n = component(4) ' Calls factorial method as default. | |
To specify a default method, include an attribute assigning a special dispatch identifier (a dispid) to the method. For more information about dispids, see Exposing Events.
To specify a default method
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In the <method> element, include the attribute dispid="0", as shown in the following example:
Copy Code<public> <method name="factorial" dispid="0"/> </public>
Note This technique can be used to assign either a default method or a default property, but not both. There can be only one element in the script component with the dispid of zero.
See Also
