why can quotes be left out in names of gradle task

问题:

I don't understand why we don't need to add quotes to the name of gradle task when we declare it like:

task hello (type : DefaultTask) {
}

I've tried in a groovy project and found that it's illegal, how gradle makes it works. And I don't understand the expression above neither, why we can add (type : DefaultTask), how can we analyze it with groovy grammar?

回答1:

As an example in a GroovyConsole runnable form, you can define a bit of code thusly:

// Set the base class for our DSL

@BaseScript(MyDSL)
import groovy.transform.BaseScript

// Something to deal with people
class Person { 
    String name
    Closure method
    String toString() { "$name" }
    Person(String name, Closure cl) {
        this.name = name
        this.method = cl
        this.method.delegate = this
    }
    def greet(String greeting) {
        println "$greeting $name"
    }
}

//  and our base DSL class

abstract class MyDSL extends Script {
    def methodMissing(String name, args) {
        return new Person(name, args[0])
    }

    def person(Person p) {
        p.method(p)
    }
}

// Then our actual script

person tim {
    greet 'Hello'
}

So when the script at the bottom is executed, it prints Hello tim to stdout

But David's answer is the correct one, this is just for example

See also here in the documentation for Groovy

回答2:

A Gradle build script is a Groovy DSL application. By careful use of "methodMissing" and "propertyMissing" methods, all magic is possible.

I don't remember the exact mechanism around "task ". I think this was asked in the Gradle forum (probably more than once).