groovy.lang
Class Closure

java.lang.Object
  groovy.lang.GroovyObjectSupport
      groovy.lang.Closure

All Implemented Interfaces:

Cloneable

class Closure
extends GroovyObjectSupport

Represents any closure object in Groovy.

Groovy allows instances of Closures to be called in a short form. For example:

   def a = 1
   def c = {a}
   assert c() == 1
 

   def a = 1
   def c = {a}
   assert c.call() == 1
 

author:

James Strachan

author:

John Wilson

author:

Jochen Theodorou

author:

Graeme Rocher

version:

$Revision: 18300 $

DELEGATE_FIRST

static final int DELEGATE_FIRST

With this resolveStrategy set the closure will attempt to resolve property references to the delegate first

DELEGATE_ONLY

static final int DELEGATE_ONLY

With this resolveStrategy set the closure will resolve property references to the delegate only and entirely bypass the owner

DONE

static final int DONE

OWNER_FIRST

static final int OWNER_FIRST

With this resolveStrategy set the closure will attempt to resolve property references to the owner first

OWNER_ONLY

static final int OWNER_ONLY

With this resolveStrategy set the closure will resolve property references to the owner only and not call the delegate at all

SKIP

static final int SKIP

TO_SELF

static final int TO_SELF

With this resolveStrategy set the closure will resolve property references to itself and go through the usual MetaClass look-up process. This allows the developer to override getProperty using ExpandoMetaClass of the closure itself

maximumNumberOfParameters

protected int maximumNumberOfParameters

parameterTypes

protected Class[] parameterTypes

Closure

public Closure(Object owner, Object thisObject)

Closure

public Closure(Object owner)

asWritable

public Closure asWritable()

return:

a version of this closure which implements Writable. Note that the returned Writable also overrides #toString() in order to allow rendering the result directly to a String.

call

public Object call()

Invokes the closure without any parameters, returning any value if applicable.

return:

the value if applicable or null if there is no return statement in the closure

call

public Object call(Object[] args)

call

public Object call(Object arguments)

Invokes the closure, returning any value if applicable.

param:

arguments could be a single value or a List of values

return:

the value if applicable or null if there is no return statement in the closure

clone

public Object clone()

curry

public Closure curry(Object[] arguments)

Support for closure currying

param:

arguments the arguments to bind

return:

the new closure with its arguments bound

getDelegate

public Object getDelegate()

return:

the delegate Object to which method calls will go which is typically the outer class when the closure is constructed

getDirective

public int getDirective()

return:

Returns the directive.

getMaximumNumberOfParameters

public int getMaximumNumberOfParameters()

return:

the maximum number of parameters a doCall method of this closure can take

getOwner

public Object getOwner()

return:

the owner Object to which method calls will go which is typically the outer class when the closure is constructed

getParameterTypes

public Class[] getParameterTypes()

return:

the parameter types of the longest doCall method of this closure

getProperty

public Object getProperty(String property)

getResolveStrategy

public int getResolveStrategy()

Gets the strategy which the closure users to resolve methods and properties

return:

The resolve strategy

see:

Closure#DELEGATE_FIRST

see:

Closure#DELEGATE_ONLY

see:

Closure#OWNER_FIRST

see:

Closure#OWNER_ONLY

see:

Closure#TO_SELF

getThisObject

public Object getThisObject()

isCase

public boolean isCase(Object candidate)

run

public void run()

setDelegate

public void setDelegate(Object delegate)

Allows the delegate to be changed such as when performing markup building

param:

delegate the new delegate

setDirective

public void setDirective(int directive)

param:

directive The directive to set.

setProperty

public void setProperty(String property, Object newValue)

setResolveStrategy

public void setResolveStrategy(int resolveStrategy)

Sets the strategy which the closure uses to resolve property references. The default is Closure.OWNER_FIRST

param:

resolveStrategy The resolve strategy to set

see:

Closure#DELEGATE_FIRST

see:

Closure#DELEGATE_ONLY

see:

Closure#OWNER_FIRST

see:

Closure#OWNER_ONLY

see:

Closure#TO_SELF

throwRuntimeException

protected static Object throwRuntimeException(Throwable throwable)

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