org.mozilla.javascript.WrapFactory Maven / Gradle / Ivy
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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// API class
package org.mozilla.javascript;
/**
* Embeddings that wish to provide their own custom wrappings for Java
* objects may extend this class and call
* {@link Context#setWrapFactory(WrapFactory)}
* Once an instance of this class or an extension of this class is enabled
* for a given context (by calling setWrapFactory on that context), Rhino
* will call the methods of this class whenever it needs to wrap a value
* resulting from a call to a Java method or an access to a Java field.
*
* @see org.mozilla.javascript.Context#setWrapFactory(WrapFactory)
* @since 1.5 Release 4
*/
public class WrapFactory
{
/**
* Wrap the object.
*
* The value returned must be one of
*
* - java.lang.Boolean
* - java.lang.String
* - java.lang.Number
* - org.mozilla.javascript.Scriptable objects
* - The value returned by Context.getUndefinedValue()
* - null
*
* @param cx the current Context for this thread
* @param scope the scope of the executing script
* @param obj the object to be wrapped. Note it can be null.
* @param staticType type hint. If security restrictions prevent to wrap
object based on its class, staticType will be used instead.
* @return the wrapped value.
*/
public Object wrap(Context cx, Scriptable scope,
Object obj, Class staticType)
{
if (obj == null || obj == Undefined.instance
|| obj instanceof Scriptable)
{
return obj;
}
if (staticType != null && staticType.isPrimitive()) {
if (staticType == Void.TYPE)
return Undefined.instance;
if (staticType == Character.TYPE)
return Integer.valueOf(((Character) obj).charValue());
return obj;
}
if (!isJavaPrimitiveWrap()) {
if (obj instanceof String || obj instanceof Number
|| obj instanceof Boolean)
{
return obj;
} else if (obj instanceof Character) {
return String.valueOf(((Character)obj).charValue());
}
}
Class cls = obj.getClass();
if (cls.isArray()) {
return NativeJavaArray.wrap(scope, obj);
}
return wrapAsJavaObject(cx, scope, obj, staticType);
}
/**
* Wrap an object newly created by a constructor call.
* @param cx the current Context for this thread
* @param scope the scope of the executing script
* @param obj the object to be wrapped
* @return the wrapped value.
*/
public Scriptable wrapNewObject(Context cx, Scriptable scope, Object obj)
{
if (obj instanceof Scriptable) {
return (Scriptable)obj;
}
Class cls = obj.getClass();
if (cls.isArray()) {
return NativeJavaArray.wrap(scope, obj);
}
return wrapAsJavaObject(cx, scope, obj, null);
}
/**
* Wrap Java object as Scriptable instance to allow full access to its
* methods and fields from JavaScript.
*
* {@link #wrap(Context, Scriptable, Object, Class)} and
* {@link #wrapNewObject(Context, Scriptable, Object)} call this method
* when they can not convert javaObject to JavaScript primitive
* value or JavaScript array.
*
* Subclasses can override the method to provide custom wrappers
* for Java objects.
* @param cx the current Context for this thread
* @param scope the scope of the executing script
* @param javaObject the object to be wrapped
* @param staticType type hint. If security restrictions prevent to wrap
object based on its class, staticType will be used instead.
* @return the wrapped value which shall not be null
*/
public Scriptable wrapAsJavaObject(Context cx, Scriptable scope,
Object javaObject, Class staticType)
{
return new NativeJavaObject(scope, javaObject, staticType);
}
/**
* Wrap a Java class as Scriptable instance to allow access to its static
* members and fields and use as constructor from JavaScript.
*
* Subclasses can override this method to provide custom wrappers for
* Java classes.
*
* @param cx the current Context for this thread
* @param scope the scope of the executing script
* @param javaClass the class to be wrapped
* @return the wrapped value which shall not be null
* @since 1.7R3
*/
public Scriptable wrapJavaClass(Context cx, Scriptable scope,
Class javaClass)
{
return new NativeJavaClass(scope, javaClass);
}
/**
* Return false if result of Java method, which is instance of
* String, Number, Boolean and
* Character, should be used directly as JavaScript primitive
* type.
* By default the method returns true to indicate that instances of
* String, Number, Boolean and
* Character should be wrapped as any other Java object and
* scripts can access any Java method available in these objects.
* Use {@link #setJavaPrimitiveWrap(boolean)} to change this.
*/
public final boolean isJavaPrimitiveWrap()
{
return javaPrimitiveWrap;
}
/**
* @see #isJavaPrimitiveWrap()
*/
public final void setJavaPrimitiveWrap(boolean value)
{
Context cx = Context.getCurrentContext();
if (cx != null && cx.isSealed()) {
Context.onSealedMutation();
}
javaPrimitiveWrap = value;
}
private boolean javaPrimitiveWrap = true;
}