Explain what GiA says about accessing extension properties?

(davidmichaelkarr) #1

In “Gradle in Action”, section 8.5.4, “Plugin extension mechanism”, there is the following paragraph: > Every task of your plugin has a property named conventionMapping. To > be more specific, every task derived from DefaultTask owns this > property. You use this property to assign the extension model values > to a task’s input or output fields. By wrapping the extension model > value into a closure, you lazily set these values. This means that the > value is only calculated when the task is executed. To retrieve the > values of a property stored in convention mapping, you’ll need to > explicitly use getter methods, as shown in the next listing. Keep in > mind that trying to access a field directly will result in a null > value.

I was following this paragraph fine until the bolded sentence. I’m not sure what the point is there. Can someone elaborate on this?

(Peter Niederwieser) #2

To access property ‘foo’ declared in the same class, it’s necessary to use ‘getFoo()’ rather than ‘foo’. Otherwise, convention mapping won’t kick in.

(davidmichaelkarr) #3

Ok, perhaps I should rephrase the question.

I understand exactly what it’s saying. What I want to know is why. Your answer just reiterated what the statement said.

(Peter Niederwieser) #4

‘getFoo’ calls the generated getter that contains the convention mapping logic. ‘foo’ accesses the field directly and bypasses that logic.

(Benjamin Muschko) #5

If you have specific questions about the book, you might rather want to post it on Manning’s author forum in the future.