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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;
/**
* This is interface that all objects in JavaScript must implement. The interface provides for the
* management of properties and for performing conversions.
*
* Host system implementors may find it easier to extend the ScriptableObject class rather than
* implementing Scriptable when writing host objects.
*
*
There are many static methods defined in ScriptableObject that perform the multiple calls to
* the Scriptable interface needed in order to manipulate properties in prototype chains.
*
*
*
* @see org.mozilla.javascript.ScriptableObject
* @author Norris Boyd
* @author Nick Thompson
* @author Brendan Eich
*/
public interface Scriptable {
/**
* Get the name of the set of objects implemented by this Java class. This corresponds to the
* [[Class]] operation in ECMA and is used by Object.prototype.toString() in ECMA.
*
*
See ECMA 8.6.2 and 15.2.4.2.
*/
public String getClassName();
/** Value returned from get if the property is not found. */
public static final Object NOT_FOUND = UniqueTag.NOT_FOUND;
/**
* Get a named property from the object.
*
*
Looks property up in this object and returns the associated value if found. Returns
* NOT_FOUND if not found. Note that this method is not expected to traverse the prototype
* chain. This is different from the ECMA [[Get]] operation.
*
*
Depending on the property selector, the runtime will call this method or the form of
* get that takes an integer:
*
*
* JavaScript code Java code a.b a.get("b", a) a["foo"] a.get("foo", a) a[3] a.get(3, a) a["3"] a.get(3, a) a[3.0] a.get(3, a) a["3.0"] a.get("3.0", a) a[1.1] a.get("1.1", a) a[-4] a.get(-4, a)
*
* The values that may be returned are limited to the following:
*
*
* - java.lang.Boolean objects
*
- java.lang.String objects
*
- java.lang.Number objects
*
- org.mozilla.javascript.Scriptable objects
*
- null
*
- The value returned by Context.getUndefinedValue()
*
- NOT_FOUND
*
*
* @param name the name of the property
* @param start the object in which the lookup began
* @return the value of the property (may be null), or NOT_FOUND
* @see org.mozilla.javascript.Context#getUndefinedValue
*/
public Object get(String name, Scriptable start);
/**
* Get a property from the object selected by an integral index.
*
* Identical to get(String, Scriptable) except that an integral index is used to
* select the property.
*
* @param index the numeric index for the property
* @param start the object in which the lookup began
* @return the value of the property (may be null), or NOT_FOUND
* @see org.mozilla.javascript.Scriptable#get(String,Scriptable)
*/
public Object get(int index, Scriptable start);
/**
* Indicates whether or not a named property is defined in an object.
*
*
Does not traverse the prototype chain.
*
*
The property is specified by a String name as defined for the get method.
*
*
*
* @param name the name of the property
* @param start the object in which the lookup began
* @return true if and only if the named property is found in the object
* @see org.mozilla.javascript.Scriptable#get(String, Scriptable)
* @see org.mozilla.javascript.ScriptableObject#getProperty(Scriptable, String)
*/
public boolean has(String name, Scriptable start);
/**
* Indicates whether or not an indexed property is defined in an object.
*
*
Does not traverse the prototype chain.
*
*
The property is specified by an integral index as defined for the get method.
*
*
*
* @param index the numeric index for the property
* @param start the object in which the lookup began
* @return true if and only if the indexed property is found in the object
* @see org.mozilla.javascript.Scriptable#get(int, Scriptable)
* @see org.mozilla.javascript.ScriptableObject#getProperty(Scriptable, int)
*/
public boolean has(int index, Scriptable start);
/**
* Sets a named property in this object.
*
*
The property is specified by a string name as defined for get.
*
*
The possible values that may be passed in are as defined for get. A class
* that implements this method may choose to ignore calls to set certain properties, in which
* case those properties are effectively read-only.
*
*
For properties defined in a prototype chain, use putProperty in
* ScriptableObject.
*
*
Note that if a property a is defined in the prototype p of an object
* o, then evaluating o.a = 23 will cause set to be called on
* the prototype p with o as the start parameter. To preserve JavaScript
* semantics, it is the Scriptable object's responsibility to modify o.
*
*
This design allows properties to be defined in prototypes and implemented in terms of
* getters and setters of Java values without consuming slots in each instance.
*
*
The values that may be set are limited to the following:
*
*
* - java.lang.Boolean objects
*
- java.lang.String objects
*
- java.lang.Number objects
*
- org.mozilla.javascript.Scriptable objects
*
- null
*
- The value returned by Context.getUndefinedValue()
*
*
* Arbitrary Java objects may be wrapped in a Scriptable by first calling
* Context.toObject. This allows the property of a JavaScript object to contain an
* arbitrary Java object as a value.
*
*
Note that has will be called by the runtime first before set is
* called to determine in which object the property is defined. Note that this method is not
* expected to traverse the prototype chain, which is different from the ECMA [[Put]] operation.
*
* @param name the name of the property
* @param start the object whose property is being set
* @param value value to set the property to
* @see org.mozilla.javascript.Scriptable#has(String, Scriptable)
* @see org.mozilla.javascript.Scriptable#get(String, Scriptable)
* @see org.mozilla.javascript.ScriptableObject#putProperty(Scriptable, String, Object)
* @see org.mozilla.javascript.Context#toObject(Object, Scriptable)
*/
public void put(String name, Scriptable start, Object value);
/**
* Sets an indexed property in this object.
*
*
The property is specified by an integral index as defined for get.
*
*
Identical to put(String, Scriptable, Object) except that an integral index is
* used to select the property.
*
* @param index the numeric index for the property
* @param start the object whose property is being set
* @param value value to set the property to
* @see org.mozilla.javascript.Scriptable#has(int, Scriptable)
* @see org.mozilla.javascript.Scriptable#get(int, Scriptable)
* @see org.mozilla.javascript.ScriptableObject#putProperty(Scriptable, int, Object)
* @see org.mozilla.javascript.Context#toObject(Object, Scriptable)
*/
public void put(int index, Scriptable start, Object value);
/**
* Removes a property from this object. This operation corresponds to the ECMA [[Delete]] except
* that the no result is returned. The runtime will guarantee that this method is called only if
* the property exists. After this method is called, the runtime will call Scriptable.has to see
* if the property has been removed in order to determine the boolean result of the delete
* operator as defined by ECMA 11.4.1.
*
*
A property can be made permanent by ignoring calls to remove it.
*
*
The property is specified by a String name as defined for get.
*
*
To delete properties defined in a prototype chain, see deleteProperty in ScriptableObject.
*
* @param name the identifier for the property
* @see org.mozilla.javascript.Scriptable#get(String, Scriptable)
* @see org.mozilla.javascript.ScriptableObject#deleteProperty(Scriptable, String)
*/
public void delete(String name);
/**
* Removes a property from this object.
*
*
The property is specified by an integral index as defined for get.
*
*
To delete properties defined in a prototype chain, see deleteProperty in ScriptableObject.
*
*
Identical to delete(String) except that an integral index is used to select
* the property.
*
* @param index the numeric index for the property
* @see org.mozilla.javascript.Scriptable#get(int, Scriptable)
* @see org.mozilla.javascript.ScriptableObject#deleteProperty(Scriptable, int)
*/
public void delete(int index);
/**
* Get the prototype of the object.
*
* @return the prototype
*/
public Scriptable getPrototype();
/**
* Set the prototype of the object.
*
* @param prototype the prototype to set
*/
public void setPrototype(Scriptable prototype);
/**
* Get the parent scope of the object.
*
* @return the parent scope
*/
public Scriptable getParentScope();
/**
* Set the parent scope of the object.
*
* @param parent the parent scope to set
*/
public void setParentScope(Scriptable parent);
/**
* Get an array of property ids.
*
*
Not all property ids need be returned. Those properties whose ids are not returned are
* considered non-enumerable.
*
* @return an array of Objects. Each entry in the array is either a java.lang.String or a
* java.lang.Number
*/
public Object[] getIds();
/**
* Get the default value of the object with a given hint. The hints are String.class for type
* String, Number.class for type Number, Scriptable.class for type Object, and Boolean.class for
* type Boolean.
*
*
A hint of null means "no hint".
*
*
See ECMA 8.6.2.6.
*
* @param hint the type hint
* @return the default value
*/
public Object getDefaultValue(Class hint);
/**
* The instanceof operator.
*
*
The JavaScript code "lhs instanceof rhs" causes rhs.hasInstance(lhs) to be called.
*
*
The return value is implementation dependent so that embedded host objects can return an
* appropriate value. See the JS 1.3 language documentation for more detail.
*
*
This operator corresponds to the proposed EMCA [[HasInstance]] operator.
*
* @param instance The value that appeared on the LHS of the instanceof operator
* @return an implementation dependent value
*/
public boolean hasInstance(Scriptable instance);
}