This message was deleted.

Stranger yet, if I run

gradle greeting -Pgreeting.message="hello3"

then I get the output

hello2 and salutations2

What I understand is happening is that during the configuration phase, the

greeting {}

extension's properties are not yet accessible, so when

extension.getMessage().get()

is called, it returns the value set in the

convention

method Is there a way to get the value defined in the

greeting {}

extension (i.e. the value

'hello2'

) during the configuration phase?

The idea of Properties is, that you don’t call

get()

at configuration time, but you use for example

map()

. In your case you could do:

Property<String> message = extension.getMessage().map(it -> {
    // if else logic here
})

project.getTasks().register("greetingTask", task -> {
    // Note: Accessing a property outside of doFirst/doLast or methods annotated with @TaskAction is actually a configuration phase
    doLast(task -> {
        // Accessing a property in doFirst/doLast is an execution phase
        System.out.println(message.get())
    });
});

Thank you Anze I have a followup question: If I am not supposed to access an extension Property during configuration time, what is the best practice for capturing user input to configure plugin configuration-time behavior? (assuming that accessing the user input during configuration time is a strict constraint that cannot be worked around)

Best practice is, that you don’t decide anything at the configuration phase. In configuration phase you only wire inputs to tasks. E.g. if user input is

-Pgreeting.message

then you make this a task input via

project.getProviders().gradleProperty("greeting.message")

. And then inside a task action you do if/else or some logic and decide what will you do with that user input. But yeah, for some special cases that might be sometimes difficult.

The usual pattern is, that you do not set properties then in the extension, but that the extension has functions that the user calls. So for example

greeting {
    setMessage('hello2')
}

and then you can do the relevant things in the

setMessage

function of the the extension.

For the sake of comparison, the way my plugin is currently written (not the toy example above) is that it accesses properties that are set via

-Pflags

and via the

ext {}

block in the

build.gradle

file. These gradle properties are always accessible, so I can use them to decide stuff during the configuration phase