groovy.util

Class DelegatingScript

java.lang.Object

groovy.lang.GroovyObjectSupport

groovy.lang.Script

groovy.util.DelegatingScript

All Implemented Interfaces:

GroovyObject

public abstract class DelegatingScript
extends Script

Script that performs method invocations and property access like Closure does.

DelegatingScript is a convenient basis for loading a custom-defined DSL as a Script, then execute it. The following sample code illustrates how to do it:

 class MyDSL {
     public void foo(int x, int y, Closure z) { ... }
     public void setBar(String a) { ... }
 }

 CompilerConfiguration cc = new CompilerConfiguration();
 cc.setScriptBaseClass(DelegatingScript.class);
 GroovyShell sh = new GroovyShell(cl,new Binding(),cc);
 DelegatingScript script = (DelegatingScript)sh.parse(new File("my.dsl"))
 script.setDelegate(new MyDSL());
 script.run();
 

my.dsl can look like this:

 foo(1,2) {
     ....
 }
 bar = ...;
 

DelegatingScript does this by delegating property access and method invocation to the delegate object.

More formally speaking, given the following script:

 a = 1;
 b(2);
 

Using DelegatingScript as the base class, the code will run as:

 delegate.a = 1;
 delegate.b(2);
 

... whereas in plain Script, this will be run as:

 binding.setProperty("a",1);
 ((Closure)binding.getProperty("b")).call(2);
 

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DelegatingScript()
protected	DelegatingScript(Binding binding)

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Object	getDelegate()
java.lang.Object	getProperty(java.lang.String property) Retrieves a property value.
java.lang.Object	invokeMethod(java.lang.String name, java.lang.Object args) Invoke a method (or closure in the binding) defined.
void	setDelegate(java.lang.Object delegate) Sets the delegation target.
void	setProperty(java.lang.String property, java.lang.Object newValue) Sets the given property to the new value.

Methods inherited from class groovy.lang.Script

evaluate, evaluate, getBinding, print, printf, printf, println, println, run, run, setBinding

Methods inherited from class groovy.lang.GroovyObjectSupport

getMetaClass, setMetaClass

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DelegatingScript

protected DelegatingScript()

DelegatingScript

protected DelegatingScript(Binding binding)

Method Detail

setDelegate

public void setDelegate(java.lang.Object delegate)

Sets the delegation target.

invokeMethod

public java.lang.Object invokeMethod(java.lang.String name,
                            java.lang.Object args)

Description copied from class: Script

Invoke a method (or closure in the binding) defined.

Specified by:

invokeMethod in interface GroovyObject

Overrides:

invokeMethod in class Script

Parameters:

name - method to call

args - arguments to pass to the method

Returns:

value

getProperty

public java.lang.Object getProperty(java.lang.String property)

Description copied from interface: GroovyObject

Retrieves a property value.

Specified by:

getProperty in interface GroovyObject

Overrides:

getProperty in class Script

Parameters:

property - the name of the property of interest

Returns:

the given property

setProperty

public void setProperty(java.lang.String property,
               java.lang.Object newValue)

Description copied from interface: GroovyObject

Sets the given property to the new value.

Specified by:

setProperty in interface GroovyObject

Overrides:

setProperty in class Script

Parameters:

property - the name of the property of interest

newValue - the new value for the property

getDelegate

public java.lang.Object getDelegate()