How to override an existing check

[Philipp Salvisberg]

This questions was asked by @S-Koell in another forum. Here's the relevant part:

As descussed here:

Trivadis/plsql-and-sql-coding-guidelines#78

I want to write my own validator based on the TrivadisGuidelines3Plus.xtend.

In my case I want to override the G-1050 but I'm really struggling because first of all I don't know what >the method is called to override. I was guessing "checkGuideline1050" because some with other >numbers exist. But 1050 doesnt.

Basically I want something like:

override checkGuideline1050(FunctionHeading f){
   if(NOT f.function.startsWith('logger')){
       super.checkGuideline1050(f);
   }
}```

Could you please give me guidance on how to approach this? 

[Philipp Salvisberg]

@S-Koell The guideline check G-1050 was already part of the Trivadis guidelines v2. Back then it was named G-05. Hence the check methods were also named checkGuideline5. There are two implemented one for string literals and one for number literals. I've created an example where I've re-implemented the guideline completely. See here. In your case you could also simplify the implementation to:

@Check
override checkGuideline5(SimpleExpressionStringValue literal) {
    if (!literal.isLoggerCall) {
        super.checkGuideline5(literal)
    }
}

It's a bit tricky to navigate the parse tree. I typically implement the code with the help of the debugger, which I call from a test.

[Sebastian Köll]

Sorry for the late response but: WOW huge thanks for actually coding everything there!

But shouldn't it be:

        @Check
	override checkGuideline5(SimpleExpressionStringValue literal) {
		if ( !literal.isLoggerCall ) {
			super(literal); 
		}
	}

And I think this issue here is the right place to ask the development topics from the issue #10 :
How could I have known what to do there myself? So many questions from my side:

• How would I find the correct method to override
• With no idea what the classes are representing there is no way I could have coded that ( e.g. what is SimpleExpressionStringValue, BinaryCompoundExpressionLevel6 , ... )
• Is there an Documentation for development etc.. ?

[Philipp Salvisberg]

No, super.checkGuideline5(literal) is correct. You just want to execute the standard behavior when the expression is not part of the logger call.

Regarding the other questions, I suggest to open dedicated issues. Thank you.

[Sebastian Köll]

You just want to execute the standard behavior when the expression is not part of the logger call.

I agree.
But currently the code is:

if (!literal.isConstantDeclaration && !literal.isLoggerCall) {
			warning(1050, literal, literal)
		}

No call to super. That's why I asked if it's correct.

[Philipp Salvisberg]

The current implementation is not wrong. It just reimplements the validation completely. I wanted to make clear that reusing the existing implementation is also possible.

[Sebastian Köll]

Understood. I thought that this could be the case but I couldn't be sure without knowing the default implementation, hence the question.

Thanks for clarification and a HUGE thanks for all the great and fast support you give!