Fix a NullPointerException throwing during refactoring.

[DayS]

Let the inform compiler the developer about the missing constant. This is related to #616, #612, and #530

[JoanZapata]

How is this ...

Then, we just have to rename the id attribute in the layout to see the error.

... related to that?

Progress: I was able to eliminate the error by removing all @click annotations in my project, even though there were no error markers at those annotations. Once I added one of the @click annotations, the error appeared again, this time located at the declaration of the class that contained the click listeners.

[DayS]

I think there are multiple way to have this error. The refactoring is one of them, but the cause is always the same : the id's field have a null value even if there is something written in the code.

In my case, because R.id.xxx doesn't exists, there is a Java compilation error on this. But the annotation processing seems to run anyway and considere the value is null.

In the case of #530, I suspect the same kind of thing. But as the error can shows up everywhere in the code, I think it's why this seems so weird.

I don't know if I'm clear but it's hard to understand without try to make it crash :)

[JoanZapata]

And how does an empty array solve this problem ? Doesn't it break the generated classes ?

[DayS]

Just follows the hierarchy calls. I think it should works :-)

[DayS]

For example, for extractAnnotationResIdValueParameter, it's only called twice (here and here) and each time we check if the resulting resIds is empty or default. If so, we fallback to check with resName then method name.

[JoanZapata]

I don't get it.

@Click(R.id.foo)
public void bar(){ }

If the error occurs, even with the fallbacks, what does the generated code looks like?

[DayS]

This should works and reduce issues number by 20% :D