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Groovy closures have three contexts for resolving names:

• owner — the enclosing scope (where the closure was defined)
• delegate — a configurable target (default: same as owner)
• this — the enclosing class

This is what makes Gradle's task { ... } style work — the closure's delegate is set to the task being configured, so methods like dependsOn resolve against it.

class Person {
    String name
    int age
}

def configure(closure) {
    def p = new Person()
    closure.delegate = p
    closure.resolveStrategy = Closure.DELEGATE_FIRST
    closure.call()
    return p
}

def ada = configure {
    name = "Ada"        // sets p.name (delegate-first)
    age = 36
}

println ada.name        // "Ada"

Resolve strategies:

• Closure.OWNER_FIRST (default) — owner scope wins
• Closure.DELEGATE_FIRST — delegate wins
• Closure.OWNER_ONLY / DELEGATE_ONLY

Pattern: builders. A builder method takes a closure, sets its delegate, and runs it:

def html(@DelegatesTo(HtmlBuilder) Closure body) {
    new HtmlBuilder().with(body)
}

html {
    title "Hello"
    body {
        p "World"
    }
}

Gradle, MarkupBuilder, JsonBuilder all use this pattern.