org.zkoss.zk.ui.ext
Class Scopes

java.lang.Object
  org.zkoss.zk.ui.ext.Scopes

public class Scopes
extends java.lang.Object

Utilities to manage the current scope (Scope).

Since:

5.0.0

Author:

tomyeh

Constructor Summary

Scopes()

Method Summary

static void	afterInterpret() Used with beforeInterpret(org.zkoss.zk.ui.ext.Scope) to clean up implicit variables.
static Scope	beforeInterpret(Scope scope) Prepares implicit variable before calling Page.interpret(java.lang.String, java.lang.String, org.zkoss.zk.ui.ext.Scope).
static Scope	getCurrent(Page page) Returns the current scope.
static java.lang.Object	getImplicit(java.lang.String name, java.lang.Object defValue) Returns the implicit object.
static void	setImplicit(java.lang.String name, java.lang.Object value) Sets an implicit object.

Methods inherited from class java.lang.Object

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

Constructor Detail

Scopes

public Scopes()

Method Detail

beforeInterpret

public static final Scope beforeInterpret(Scope scope)

Prepares implicit variable before calling Page.interpret(java.lang.String, java.lang.String, org.zkoss.zk.ui.ext.Scope).

Typical use:

final Scope scope = Scopes.beforeInterpret(comp);
try {
  Scopes.setImplicit("some", value);
  page.interpret(zslang, zscript, scope); //it will push scope as the current scope
} finally {
  Scopes.afterInterpret();
}

Another example:

Scopes.beforeInterpret(comp);
try {
  constr.validate(comp); //if constr might be an instance of a class implemented in zscript
} finally {
  Scopess.afterInterpret();
}

If you need to set some implicit variables, you can invoke setImplicit(java.lang.String, java.lang.Object) between beforeInterpret(org.zkoss.zk.ui.ext.Scope) and afterInterpret().

Parameters:

scope - the scope, never null.

Returns:

the scope used for interpretation. It is the same as the scope parameter if it is not null. Otherwise, a temporary scope is created.

afterInterpret

public static final void afterInterpret()

Used with beforeInterpret(org.zkoss.zk.ui.ext.Scope) to clean up implicit variables.

setImplicit

public static void setImplicit(java.lang.String name,
                               java.lang.Object value)

Sets an implicit object. It can be called only between beforeInterpret(org.zkoss.zk.ui.ext.Scope) and afterInterpret().

getImplicit

public static java.lang.Object getImplicit(java.lang.String name,
                                           java.lang.Object defValue)

Returns the implicit object.

It searches the implicit object stored with setImplicit(java.lang.String, java.lang.Object), and also searches the system implicit objects by use of Components.getImplicit(Page, Component, String).

Parameters:

name - the variable to retrieve

defValue - the default vale that is used if the implicit object is not defined.

getCurrent

public static final Scope getCurrent(Page page)

Returns the current scope. The current scope is the event target's scope if this thread is processing an event (Event.getTarget(). Otherwise, the scope of the page specified is assumed.

This method is used only to implement Interpreter. You rarely need to access it other than implementing an interpreter.

Parameters:

page - the page. It is used if beforeInterpret(org.zkoss.zk.ui.ext.Scope) is not called before. If null, the current page (ExecutionCtrl.getCurrentPage() is assumed.