org.mozilla.javascript

Class NativeJavaArray

Implemented Interfaces:
Scriptable, Serializable, Wrapper

public class NativeJavaArray
extends NativeJavaObject

This class reflects Java arrays into the JavaScript environment.
Author:
Mike Shaver
See Also:
NativeJavaClass, NativeJavaObject, NativeJavaPackage

Field Summary

Fields inherited from class org.mozilla.javascript.NativeJavaObject

javaObject, members, parent, prototype, staticType

Fields inherited from interface org.mozilla.javascript.Scriptable

NOT_FOUND

Constructor Summary

NativeJavaArray(Scriptable scope, Object array)

Method Summary

Object
get(String id, Scriptable start)
Get a named property from the object.
Object
get(int index, Scriptable start)
Get a property from the object selected by an integral index.
String
getClassName()
Get the name of the set of objects implemented by this Java class.
Object
getDefaultValue(Class hint)
Get the default value of the object with a given hint.
Object[]
getIds()
Get an array of property ids.
Scriptable
getPrototype()
Get the prototype of the object.
boolean
has(String id, Scriptable start)
Indicates whether or not a named property is defined in an object.
boolean
has(int index, Scriptable start)
Indicates whether or not an indexed property is defined in an object.
boolean
hasInstance(Scriptable value)
The instanceof operator.
void
put(String id, Scriptable start, Object value)
Sets a named property in this object.
void
put(int index, Scriptable start, Object value)
Sets an indexed property in this object.
Object
unwrap()
Unwrap the object by returning the wrapped value.
static NativeJavaArray
wrap(Scriptable scope, Object array)

Methods inherited from class org.mozilla.javascript.NativeJavaObject

canConvert, coerceType, delete, delete, get, get, getClassName, getDefaultValue, getIds, getParentScope, getPrototype, has, has, hasInstance, initMembers, put, put, setParentScope, setPrototype, unwrap, wrap

Constructor Details

NativeJavaArray

public NativeJavaArray(Scriptable scope,
                       Object array)

Method Details

get

public Object get(String id,
                  Scriptable start)
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 codeJava 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
Specified by:
get in interface Scriptable
Overrides:
get in interface NativeJavaObject
Parameters:
start - the object in which the lookup began
Returns:
the value of the property (may be null), or NOT_FOUND

get

public Object get(int index,
                  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.
Specified by:
get in interface Scriptable
Overrides:
get in interface NativeJavaObject
Parameters:
index - the numeric index for the property
start - the object in which the lookup began
Returns:
the value of the property (may be null), or NOT_FOUND

getClassName

public String getClassName()
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.

Specified by:
getClassName in interface Scriptable
Overrides:
getClassName in interface NativeJavaObject

getDefaultValue

public Object getDefaultValue(Class hint)
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.

Specified by:
getDefaultValue in interface Scriptable
Overrides:
getDefaultValue in interface NativeJavaObject
Parameters:
hint - the type hint
Returns:
the default value

getIds

public Object[] getIds()
Get an array of property ids. Not all property ids need be returned. Those properties whose ids are not returned are considered non-enumerable.
Specified by:
getIds in interface Scriptable
Overrides:
getIds in interface NativeJavaObject
Returns:
an array of Objects. Each entry in the array is either a java.lang.String or a java.lang.Number

getPrototype

public Scriptable getPrototype()
Get the prototype of the object.
Specified by:
getPrototype in interface Scriptable
Overrides:
getPrototype in interface NativeJavaObject
Returns:
the prototype

has

public boolean has(String id,
                   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.

Specified by:
has in interface Scriptable
Overrides:
has in interface NativeJavaObject
Parameters:
start - the object in which the lookup began
Returns:
true if and only if the named property is found in the object

has

public boolean has(int index,
                   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.

Specified by:
has in interface Scriptable
Overrides:
has in interface NativeJavaObject
Parameters:
index - the numeric index for the property
start - the object in which the lookup began
Returns:
true if and only if the indexed property is found in the object

hasInstance

public boolean hasInstance(Scriptable value)
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.

Specified by:
hasInstance in interface Scriptable
Overrides:
hasInstance in interface NativeJavaObject
Parameters:
Returns:
an implementation dependent value

put

public void put(String id,
                Scriptable start,
                Object value)
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.

Specified by:
put in interface Scriptable
Overrides:
put in interface NativeJavaObject
Parameters:
start - the object whose property is being set
value - value to set the property to

put

public void put(int index,
                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.

Specified by:
put in interface Scriptable
Overrides:
put in interface NativeJavaObject
Parameters:
index - the numeric index for the property
start - the object whose property is being set
value - value to set the property to

unwrap

public Object unwrap()
Unwrap the object by returning the wrapped value.
Specified by:
unwrap in interface Wrapper
Overrides:
unwrap in interface NativeJavaObject
Returns:
a wrapped value

wrap

public static NativeJavaArray wrap(Scriptable scope,
                                   Object array)