Progress KB - How to dynamically instantiate classes and invoke methods on them ?




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How to dynamically instantiate classes and invoke methods on them ?

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TitleHow to dynamically instantiate classes and invoke methods on them ?
URL Name000031227
Article Number000172309
EnvironmentOpenEdge 10.2B
OpenEdge 11.0
All supported operating systems
Question/Problem Description
In some use cases (for example in factory classes that can create different types of class instances), it's desirable to invoke a standard method name, based on only an object type name.

How to achieve this ?
Steps to Reproduce
Clarifying Information
Error Message
Defect/Enhancement Number
Cause
Resolution
An easy way to achieve this is by implementing the following steps:


1. Make sure all classes that can be instantiated share a common type, for example by inheriting from the same base class or implementing the same interface.

2. Make sure the method name to invoke is defined in this common type.

3. Define a variable of this common type.

4, Use the DYNAMIC-NEW () function to instantiate the actual instances, and store the references in the variable.

5. Invoke the standard method names from the variable.


Attached .zip file contains a simplified testcase showing this pattern.
Workaround
Notes
Last Modified Date9/13/2015 5:33 AM
Attachment 
Files testcase.zip
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