by Unknown user
In the previous installment I wrote a successful unit test that saved and loaded checkbox data. By way of refresher, here's that code:
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First I assign the Persister object to the ManyToMany object.
Then I set some links and very to the right-side records and verify that the ManyToMany object correctly maintains those links.
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Load procedure(long leftRecordID,CML_Data_ManyToManyLinksData linksData),virtual Save procedure(long leftRecordID,CML_Data_ManyToManyLinksData linksData),virtual |
When the , virtual attribute is present on any table method in the class the compiler creates something called a virtual method table (VMT) for that class.
If a derived class has a method with the same name and prototype as a virtual method in the parent class, and that method has the , virtual attribute, then any time the parent method is called the runtime library consults the VMT to see if there is a derived method that should be called instead.
Virtual methods are one of the most powerful and compelling features of object-oriented programming. They allow you to selectively replace code in a parent class with your own code. Among other things, they are the mechanism by which most embed code is inserted into ABC applications.
Derived virtual methods
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Unit testing can be incredibly useful, but sometimes wiring unit-tested code into a working program reveals new issues that need to be addressed. I'll cover those next time.