org.mozilla.javascript

Class Context


public class Context
extends java.lang.Object

This class represents the runtime context of an executing script. Before executing a script, an instance of Context must be created and associated with the thread that will be executing the script. The Context will be used to store information about the executing of the script such as the call stack. Contexts are associated with the current thread using the enter() method.

The behavior of the execution engine may be altered through methods such as setErrorReporter.

Different forms of script execution are supported. Scripts may be evaluated from the source directly, or first compiled and then later executed. Interactive execution is also supported.

Some aspects of script execution, such as type conversions and object creation, may be accessed directly through methods of Context.

Authors:
Norris Boyd
Brendan Eich

See Also:
Scriptable

Field Summary

static int
FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME
If hasFeature(FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME) returns true, allow 'function memberExpression(args) { body }' to be syntax sugar for 'memberExpression = function(args) { body }', when memberExpression is not simply identifier.
static int
FEATURE_NON_ECMA_GET_YEAR
If hasFeature(FEATURE_NON_ECMA_GET_YEAR) returns true, Date.prototype.getYear subtructs 1900 only if 1900 <= date <322000.
static int
FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER
If hasFeature(RESERVED_KEYWORD_AS_IDENTIFIER) returns true, treat future reserved keyword (see Ecma-262, section 7.5.3) as ordinary identifiers but warn about this usage
static int
FEATURE_TO_STRING_AS_SOURCE
If hasFeature(FEATURE_TO_STRING_AS_SOURCE) returns true, calling toString on JS objects gives JS source with code to create an object with all enumeratable fields of the original object instead of printing "[object ]".
static int
VERSION_1_0
JavaScript 1.0
static int
VERSION_1_1
JavaScript 1.1
static int
VERSION_1_2
JavaScript 1.2
static int
VERSION_1_3
JavaScript 1.3
static int
VERSION_1_4
JavaScript 1.4
static int
VERSION_1_5
JavaScript 1.5
static int
VERSION_DEFAULT
The default version.
static int
VERSION_UNKNOWN
The unknown version.
static Object[]
emptyArgs
Convinient value to use as zero-length argument array object.
static String
errorReporterProperty
static String
languageVersionProperty

Constructor Summary

Context()
Create a new Context.

Method Summary

void
addActivationName(String name)
Add a name to the list of names forcing the creation of real activation objects for functions.
static void
addContextListener(ContextListener listener)
Add a Context listener.
void
addPropertyChangeListener(PropertyChangeListener l)
Register an object to receive notifications when a bound property has changed
static Object
call(Callable callable, Scriptable scope, Scriptable thisObj, Object[] args)
Call Callable.call(Context cx, Scriptable scope, Scriptable thisObj, Object[] args) using the Context instance associated with the current thread.
Function
compileFunction(Scriptable scope, String source, String sourceName, int lineno, Object securityDomain)
Compile a JavaScript function.
Script
compileReader(Reader in, String sourceName, int lineno, Object securityDomain)
Compiles the source in the given reader.
Script
compileReader(Scriptable scope, Reader in, String sourceName, int lineno, Object securityDomain)
Deprecated. The method implementation simply calls
Script
compileString(String source, String sourceName, int lineno, Object securityDomain)
Compiles the source in the given string.
org.mozilla.javascript.GeneratedClassLoader
createClassLoader(ClassLoader parent)
String
decompileFunction(Function fun, int indent)
Decompile a JavaScript Function.
String
decompileFunctionBody(Function fun, int indent)
Decompile the body of a JavaScript Function.
String
decompileScript(Script script, Scriptable scope, int indent)
Decompile the script.
static void
disableStaticContextListening()
Disable notifications of listeners registered with addContextListener(ContextListener) about Context events.
static Context
enter()
Get a context associated with the current thread, creating one if need be.
static Context
enter(Context cx)
Get a Context associated with the current thread, using the given Context if need be.
Object
evaluateReader(Scriptable scope, Reader in, String sourceName, int lineno, Object securityDomain)
Evaluate a reader as JavaScript source.
Object
evaluateString(Scriptable scope, String source, String sourceName, int lineno, Object securityDomain)
Evaluate a JavaScript source string.
static void
exit()
Exit a block of code requiring a Context.
ClassLoader
getApplicationClassLoader()
static Context
getCurrentContext()
Get the current Context.
org.mozilla.javascript.debug.Debugger
getDebugger()
Return the current debugger.
Object
getDebuggerContextData()
Return the debugger context data associated with current context.
Object[]
getElements(Scriptable object)
Get the elements of a JavaScript array.
ErrorReporter
getErrorReporter()
Get the current error reporter.
String
getImplementationVersion()
Get the implementation version.
int
getInstructionObserverThreshold()
Get/Set threshold of executed instructions counter that triggers call to observeInstructionCount().
int
getLanguageVersion()
Get the current language version.
Locale
getLocale()
Get the current locale.
int
getOptimizationLevel()
Get the current optimization level.
Object
getThreadLocal(Object key)
Get a value corresponding to a key.
static Object
getUndefinedValue()
Get the singleton object that represents the JavaScript Undefined value.
WrapFactory
getWrapFactory()
Return the current WrapHandler, or null if none is defined.
org.mozilla.javascript.WrapHandler
getWrapHandler()
Deprecated. As of Rhino 1.5 Release 4, use
boolean
hasCompileFunctionsWithDynamicScope()
Return whether functions are compiled by this context using dynamic scope.
boolean
hasFeature(int featureIndex)
Controls certain aspects of script semantics.
ScriptableObject
initStandardObjects()
Initialize the standard objects.
Scriptable
initStandardObjects(ScriptableObject scope)
Initialize the standard objects.
ScriptableObject
initStandardObjects(ScriptableObject scope, boolean sealed)
Initialize the standard objects.
boolean
isActivationNeeded(String name)
Check whether the name is in the list of names of objects forcing the creation of activation objects.
boolean
isGeneratingDebug()
Tell whether debug information is being generated.
boolean
isGeneratingDebugChanged()
boolean
isGeneratingSource()
Tell whether source information is being generated.
boolean
isSealed()
Checks if this is a sealed Context.
static Object
javaToJS(Object value, Scriptable scope)
Convenient method to convert java value to its closest representation in JavaScript.
Scriptable
newArray(Scriptable scope, Object[] elements)
Create an array with a set of initial elements.
Scriptable
newArray(Scriptable scope, int length)
Create an array with a specified initial length.
Scriptable
newObject(Scriptable scope)
Create a new JavaScript object.
Scriptable
newObject(Scriptable scope, String constructorName)
Create a new JavaScript object by executing the named constructor.
Scriptable
newObject(Scriptable scope, String constructorName, Object[] args)
Creates a new JavaScript object by executing the named constructor.
void
putThreadLocal(Object key, Object value)
Put a value that can later be retrieved using a given key.
void
removeActivationName(String name)
Remove a name from the list of names forcing the creation of real activation objects for functions.
static void
removeContextListener(ContextListener listener)
Remove a Context listener.
void
removePropertyChangeListener(PropertyChangeListener l)
Remove an object from the list of objects registered to receive notification of changes to a bounded property
void
removeThreadLocal(Object key)
Remove values from thread-local storage.
static void
reportError(String message)
Report an error using the error reporter for the current thread.
static void
reportError(String message, String sourceName, int lineno, String lineSource, int lineOffset)
Report an error using the error reporter for the current thread.
static EvaluatorException
reportRuntimeError(String message)
Report a runtime error using the error reporter for the current thread.
static EvaluatorException
reportRuntimeError(String message, String sourceName, int lineno, String lineSource, int lineOffset)
Report a runtime error using the error reporter for the current thread.
static void
reportWarning(String message)
Report a warning using the error reporter for the current thread.
static void
reportWarning(String message, String sourceName, int lineno, String lineSource, int lineOffset)
Report a warning using the error reporter for the current thread.
void
seal(Object sealKey)
Seal this Context object so any attempt to modify any of its properties including calling enter() and exit() methods will throw an exception.
void
setApplicationClassLoader(ClassLoader loader)
static void
setCachingEnabled(boolean cachingEnabled)
Deprecated. To enable/disable caching for a particular top scope, use ClassCache.get(Scriptable) and
void
setClassShutter(ClassShutter shutter)
Set the LiveConnect access filter for this context.
void
setCompileFunctionsWithDynamicScope(boolean flag)
Set whether functions compiled by this context should use dynamic scope.
void
setDebugger(org.mozilla.javascript.debug.Debugger debugger, Object contextData)
Set the associated debugger.
ErrorReporter
setErrorReporter(ErrorReporter reporter)
Change the current error reporter.
void
setGeneratingDebug(boolean generatingDebug)
Specify whether or not debug information should be generated.
void
setGeneratingSource(boolean generatingSource)
Specify whether or not source information should be generated.
void
setInstructionObserverThreshold(int threshold)
void
setLanguageVersion(int version)
Set the language version.
Locale
setLocale(Locale loc)
Set the current locale.
void
setOptimizationLevel(int optimizationLevel)
Set the current optimization level.
void
setSecurityController(SecurityController controller)
Set the security controller for this context.
void
setWrapFactory(WrapFactory wrapFactory)
Set a WrapFactory for this Context.
void
setWrapHandler(org.mozilla.javascript.WrapHandler wrapHandler)
Deprecated. As of Rhino 1.5 Release 4, use
boolean
stringIsCompilableUnit(String source)
Check whether a string is ready to be compiled.
static RuntimeException
throwAsScriptRuntimeEx(Throwable e)
Rethrow the exception wrapping it as the script runtime exception.
static boolean
toBoolean(Object value)
Convert the value to a JavaScript boolean value.
static double
toNumber(Object value)
Convert the value to a JavaScript Number value.
static Scriptable
toObject(Object value, Scriptable scope)
Convert the value to an JavaScript object value.
static Scriptable
toObject(Object value, Scriptable scope, Class staticType)
Deprecated. Use toObject(Object,Scriptable) instead.
static String
toString(Object value)
Convert the value to a JavaScript String value.
static Object
toType(Object value, Class desiredType)
Convert a JavaScript value into the desired type.
void
unseal(Object sealKey)
Unseal previously sealed Context object.

Field Details

FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME

public static final int FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME
If hasFeature(FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME) returns true, allow 'function memberExpression(args) { body }' to be syntax sugar for 'memberExpression = function(args) { body }', when memberExpression is not simply identifier. See Ecma-262, section 11.2 for definition of memberExpression.

Field Value:
2


FEATURE_NON_ECMA_GET_YEAR

public static final int FEATURE_NON_ECMA_GET_YEAR
If hasFeature(FEATURE_NON_ECMA_GET_YEAR) returns true, Date.prototype.getYear subtructs 1900 only if 1900 <= date <322000. The default behavior is always to subtruct 1900 as rquired by Ecma B.2.4.

Field Value:
1


FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER

public static final int FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER
If hasFeature(RESERVED_KEYWORD_AS_IDENTIFIER) returns true, treat future reserved keyword (see Ecma-262, section 7.5.3) as ordinary identifiers but warn about this usage

Field Value:
3


FEATURE_TO_STRING_AS_SOURCE

public static final int FEATURE_TO_STRING_AS_SOURCE

Field Value:
4


VERSION_1_0

public static final int VERSION_1_0
JavaScript 1.0

Field Value:
100


VERSION_1_1

public static final int VERSION_1_1
JavaScript 1.1

Field Value:
110


VERSION_1_2

public static final int VERSION_1_2
JavaScript 1.2

Field Value:
120


VERSION_1_3

public static final int VERSION_1_3
JavaScript 1.3

Field Value:
130


VERSION_1_4

public static final int VERSION_1_4
JavaScript 1.4

Field Value:
140


VERSION_1_5

public static final int VERSION_1_5
JavaScript 1.5

Field Value:
150


VERSION_DEFAULT

public static final int VERSION_DEFAULT
The default version.

Field Value:
0


VERSION_UNKNOWN

public static final int VERSION_UNKNOWN
The unknown version.

Field Value:
-1


emptyArgs

public static final Object[] emptyArgs
Convinient value to use as zero-length argument array object.


errorReporterProperty

public static final String errorReporterProperty


languageVersionProperty

public static final String languageVersionProperty

Constructor Details

Context

public Context()
Create a new Context. Note that the Context must be associated with a thread before it can be used to execute a script.

See Also:
enter()

Method Details

addActivationName

public void addActivationName(String name)
Add a name to the list of names forcing the creation of real activation objects for functions.

Parameters:
name - the name of the object to add to the list


addContextListener

public static void addContextListener(ContextListener listener)
Add a Context listener.


addPropertyChangeListener

public final void addPropertyChangeListener(PropertyChangeListener l)
Register an object to receive notifications when a bound property has changed

Parameters:
l - the listener

See Also:
java.beans.PropertyChangeEvent, removePropertyChangeListener(java.beans.PropertyChangeListener)


call

public static Object call(Callable callable,
                          Scriptable scope,
                          Scriptable thisObj,
                          Object[] args)
            throws JavaScriptException
Call Callable.call(Context cx, Scriptable scope, Scriptable thisObj, Object[] args) using the Context instance associated with the current thread. If no Context is associated with the thread, then new Context object will be temporary associated with the thread during call to Callable.

See Also:
enter(), exit()


compileFunction

public final Function compileFunction(Scriptable scope,
                                      String source,
                                      String sourceName,
                                      int lineno,
                                      Object securityDomain)
Compile a JavaScript function.

The function source must be a function definition as defined by ECMA (e.g., "function f(a) { return a; }").

Parameters:
scope - the scope to compile relative to
source - the function definition source
sourceName - a string describing the source, such as a filename
lineno - the starting line number
securityDomain - an arbitrary object that specifies security information about the origin or owner of the script. For implementations that don't care about security, this value may be null.

Returns:
a Function that may later be called

See Also:
Function


compileReader

public final Script compileReader(Reader in,
                                  String sourceName,
                                  int lineno,
                                  Object securityDomain)
            throws IOException
Compiles the source in the given reader.

Returns a script that may later be executed. Will consume all the source in the reader.

Parameters:
in - the input reader
sourceName - a string describing the source, such as a filename
lineno - the starting line number for reporting errors
securityDomain - an arbitrary object that specifies security information about the origin or owner of the script. For implementations that don't care about security, this value may be null.

Returns:
a script that may later be executed

See Also:
Script


compileReader

public final Script compileReader(Scriptable scope,
                                  Reader in,
                                  String sourceName,
                                  int lineno,
                                  Object securityDomain)
            throws IOException

Deprecated. The method implementation simply calls

compileReader(Reader in, String sourceName, int lineno, Object securityDomain) ignoring scope argument.


compileString

public final Script compileString(String source,
                                  String sourceName,
                                  int lineno,
                                  Object securityDomain)
Compiles the source in the given string.

Returns a script that may later be executed.

Parameters:
source - the source string
sourceName - a string describing the source, such as a filename
lineno - the starting line number for reporting errors
securityDomain - an arbitrary object that specifies security information about the origin or owner of the script. For implementations that don't care about security, this value may be null.

Returns:
a script that may later be executed

See Also:
Script


createClassLoader

public org.mozilla.javascript.GeneratedClassLoader createClassLoader(ClassLoader parent)


decompileFunction

public final String decompileFunction(Function fun,
                                      int indent)
Decompile a JavaScript Function.

Decompiles a previously compiled JavaScript function object to canonical source.

Returns function body of '[native code]' if no decompilation information is available.

Parameters:
fun - the JavaScript function to decompile
indent - the number of spaces to indent the result

Returns:
a string representing the function source


decompileFunctionBody

public final String decompileFunctionBody(Function fun,
                                          int indent)
Decompile the body of a JavaScript Function.

Decompiles the body a previously compiled JavaScript Function object to canonical source, omitting the function header and trailing brace. Returns '[native code]' if no decompilation information is available.

Parameters:
fun - the JavaScript function to decompile
indent - the number of spaces to indent the result

Returns:
a string representing the function body source.


decompileScript

public final String decompileScript(Script script,
                                    Scriptable scope,
                                    int indent)
Decompile the script.

The canonical source of the script is returned.

Parameters:
script - the script to decompile
scope - the scope under which to decompile
indent - the number of spaces to indent the result

Returns:
a string representing the script source


disableStaticContextListening

public static void disableStaticContextListening()
Disable notifications of listeners registered with addContextListener(ContextListener) about Context events. All currently registered listeners will be removed and any subsequent call to addContextListener(ContextListener) will throw an exception.

Embedding may use this method to prevent Context exposure to potentially untrusted code.


enter

public static Context enter()
Get a context associated with the current thread, creating one if need be. The Context stores the execution state of the JavaScript engine, so it is required that the context be entered before execution may begin. Once a thread has entered a Context, then getCurrentContext() may be called to find the context that is associated with the current thread.

Calling enter() will return either the Context currently associated with the thread, or will create a new context and associate it with the current thread. Each call to enter() must have a matching call to exit(). For example,

      Context cx = Context.enter();
      try {
          ...
          cx.evaluateString(...);
      } finally {
          Context.exit();
      }
 

Returns:
a Context associated with the current thread

See Also:
getCurrentContext(), exit()


enter

public static Context enter(Context cx)
Get a Context associated with the current thread, using the given Context if need be.

The same as enter() except that cx is associated with the current thread and returned if the current thread has no associated context and cx is not associated with any other thread.

Parameters:
cx - a Context to associate with the thread if possible

Returns:
a Context associated with the current thread


evaluateReader

public final Object evaluateReader(Scriptable scope,
                                   Reader in,
                                   String sourceName,
                                   int lineno,
                                   Object securityDomain)
            throws IOException,
                   JavaScriptException
Evaluate a reader as JavaScript source. All characters of the reader are consumed.

Parameters:
scope - the scope to execute in
in - the Reader to get JavaScript source from
sourceName - a string describing the source, such as a filename
lineno - the starting line number
securityDomain - an arbitrary object that specifies security information about the origin or owner of the script. For implementations that don't care about security, this value may be null.

Returns:
the result of evaluating the source

Throws:
JavaScriptException - if an uncaught JavaScript exception occurred while evaluating the Reader


evaluateString

public final Object evaluateString(Scriptable scope,
                                   String source,
                                   String sourceName,
                                   int lineno,
                                   Object securityDomain)
            throws JavaScriptException
Evaluate a JavaScript source string. The provided source name and line number are used for error messages and for producing debug information.

Parameters:
scope - the scope to execute in
source - the JavaScript source
sourceName - a string describing the source, such as a filename
lineno - the starting line number
securityDomain - an arbitrary object that specifies security information about the origin or owner of the script. For implementations that don't care about security, this value may be null.

Returns:
the result of evaluating the string

Throws:
JavaScriptException - if an uncaught JavaScript exception occurred while evaluating the source string

See Also:
SecurityController


exit

public static void exit()
Exit a block of code requiring a Context. Calling exit() will remove the association between the current thread and a Context if the prior call to enter() on this thread newly associated a Context with this thread. Once the current thread no longer has an associated Context, it cannot be used to execute JavaScript until it is again associated with a Context.

See Also:
org.mozilla.javascript.Context.enter


getApplicationClassLoader

public final ClassLoader getApplicationClassLoader()


getCurrentContext

public static Context getCurrentContext()
Get the current Context. The current Context is per-thread; this method looks up the Context associated with the current thread.

Returns:
the Context associated with the current thread, or null if no context is associated with the current thread.

See Also:
org.mozilla.javascript.Context.enter, exit()


getDebugger

public final org.mozilla.javascript.debug.Debugger getDebugger()
Return the current debugger.

Returns:
the debugger, or null if none is attached.


getDebuggerContextData

public final Object getDebuggerContextData()
Return the debugger context data associated with current context.

Returns:
the debugger data, or null if debugger is not attached


getElements

public final Object[] getElements(Scriptable object)
Get the elements of a JavaScript array.

If the object defines a length property convertible to double number, then the number is converted Uint32 value as defined in Ecma 9.6 and Java array of that size is allocated. The array is initialized with the values obtained by calling get() on object for each value of i in [0,length-1]. If there is not a defined value for a property the Undefined value is used to initialize the corresponding element in the array. The Java array is then returned. If the object doesn't define a length property or it is not a number, empty array is returned.

Parameters:
object - the JavaScript array or array-like object

Returns:
a Java array of objects

Since:
1.4 release 2


getErrorReporter

public final ErrorReporter getErrorReporter()
Get the current error reporter.

See Also:
ErrorReporter


getImplementationVersion

public final String getImplementationVersion()
Get the implementation version.

The implementation version is of the form

    "name langVer release relNum date"
 
where name is the name of the product, langVer is the language version, relNum is the release number, and date is the release date for that specific release in the form "yyyy mm dd".

Returns:
a string that encodes the product, language version, release number, and date.


getInstructionObserverThreshold

public final int getInstructionObserverThreshold()
Get/Set threshold of executed instructions counter that triggers call to observeInstructionCount(). When the threshold is zero, instruction counting is disabled, otherwise each time the run-time executes at least the threshold value of script instructions, observeInstructionCount() will be called.


getLanguageVersion

public final int getLanguageVersion()
Get the current language version.

The language version number affects JavaScript semantics as detailed in the overview documentation.

Returns:
an integer that is one of VERSION_1_0, VERSION_1_1, etc.


getLocale

public final Locale getLocale()
Get the current locale. Returns the default locale if none has been set.

See Also:
java.util.Locale


getOptimizationLevel

public final int getOptimizationLevel()
Get the current optimization level.

The optimization level is expressed as an integer between -1 and 9.

Since:
1.3


getThreadLocal

public final Object getThreadLocal(Object key)
Get a value corresponding to a key.

Since the Context is associated with a thread it can be used to maintain values that can be later retrieved using the current thread.

Note that the values are maintained with the Context, so if the Context is disassociated from the thread the values cannot be retreived. Also, if private data is to be maintained in this manner the key should be a java.lang.Object whose reference is not divulged to untrusted code.

Parameters:
key - the key used to lookup the value

Returns:
a value previously stored using putThreadLocal.


getUndefinedValue

public static Object getUndefinedValue()
Get the singleton object that represents the JavaScript Undefined value.


getWrapFactory

public final WrapFactory getWrapFactory()
Return the current WrapHandler, or null if none is defined.

Since:
1.5 Release 4

See Also:
org.mozilla.javascript.WrapHandler


getWrapHandler

public final org.mozilla.javascript.WrapHandler getWrapHandler()

Deprecated. As of Rhino 1.5 Release 4, use


hasCompileFunctionsWithDynamicScope

public final boolean hasCompileFunctionsWithDynamicScope()
Return whether functions are compiled by this context using dynamic scope.

If functions are compiled with dynamic scope, then they execute in the scope of their caller, rather than in their parent scope. This is useful for sharing functions across multiple scopes.

Since:
1.5 Release 1


hasFeature

public boolean hasFeature(int featureIndex)
Controls certain aspects of script semantics. Should be overwritten to alter default behavior.

Parameters:
featureIndex - feature index to check

Returns:
true if the featureIndex feature is turned on

See Also:
FEATURE_NON_ECMA_GET_YEAR, FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME, FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER, FEATURE_TO_STRING_AS_SOURCE


initStandardObjects

public final ScriptableObject initStandardObjects()
Initialize the standard objects. Creates instances of the standard objects and their constructors (Object, String, Number, Date, etc.), setting up 'scope' to act as a global object as in ECMA 15.1.

This method must be called to initialize a scope before scripts can be evaluated in that scope.

This method does not affect the Context it is called upon.

Returns:
the initialized scope


initStandardObjects

public final Scriptable initStandardObjects(ScriptableObject scope)
Initialize the standard objects. Creates instances of the standard objects and their constructors (Object, String, Number, Date, etc.), setting up 'scope' to act as a global object as in ECMA 15.1.

This method must be called to initialize a scope before scripts can be evaluated in that scope.

This method does not affect the Context it is called upon.

Parameters:
scope - the scope to initialize, or null, in which case a new object will be created to serve as the scope

Returns:
the initialized scope. The method returns the value of the scope argument if it is not null or newly allocated scope object which is an instance ScriptableObject.


initStandardObjects

public ScriptableObject initStandardObjects(ScriptableObject scope,
                                            boolean sealed)
Initialize the standard objects. Creates instances of the standard objects and their constructors (Object, String, Number, Date, etc.), setting up 'scope' to act as a global object as in ECMA 15.1.

This method must be called to initialize a scope before scripts can be evaluated in that scope.

This method does not affect the Context it is called upon.

This form of the method also allows for creating "sealed" standard objects. An object that is sealed cannot have properties added, changed, or removed. This is useful to create a "superglobal" that can be shared among several top-level objects. Note that sealing is not allowed in the current ECMA/ISO language specification, but is likely for the next version.

Parameters:
scope - the scope to initialize, or null, in which case a new object will be created to serve as the scope
sealed - whether or not to create sealed standard objects that cannot be modified.

Returns:
the initialized scope. The method returns the value of the scope argument if it is not null or newly allocated scope object.

Since:
1.4R3


isActivationNeeded

public final boolean isActivationNeeded(String name)
Check whether the name is in the list of names of objects forcing the creation of activation objects.

Parameters:
name - the name of the object to test

Returns:
true if an function activation object is needed.


isGeneratingDebug

public final boolean isGeneratingDebug()
Tell whether debug information is being generated.

Since:
1.3


isGeneratingDebugChanged

public final boolean isGeneratingDebugChanged()


isGeneratingSource

public final boolean isGeneratingSource()
Tell whether source information is being generated.

Since:
1.3


isSealed

public final boolean isSealed()
Checks if this is a sealed Context. A sealed Context instance does not allow to modify any of its properties and will throw an exception on any such attempt.

See Also:
seal(Object sealKey)


javaToJS

public static Object javaToJS(Object value,
                              Scriptable scope)
Convenient method to convert java value to its closest representation in JavaScript.

If value is an instance of String, Number, Boolean, Function or Scriptable, it is returned as it and will be treated as the corresponding JavaScript type of string, number, boolean, function and object.

Note that for Number instances during any arithmetic operation in JavaScript the engine will always use the result of Number.doubleValue() resulting in a precision loss if the number can not fit into double.

If value is an instance of Character, it will be converted to string of length 1 and its JavaScript type will be string.

The rest of values will be wrapped as LiveConnect objects by calling WrapFactory.wrap(Context cx, Scriptable scope, Object obj, Class staticType) as in:

    Context cx = Context.getCurrentContext();
    return cx.getWrapFactory().wrap(cx, scope, value, null);
 

Parameters:
value - any Java object
scope - top scope object

Returns:
value suitable to pass to any API that takes JavaScript values.


newArray

public final Scriptable newArray(Scriptable scope,
                                 Object[] elements)
Create an array with a set of initial elements.

Parameters:
scope - the scope to create the object in.
elements - the initial elements. Each object in this array must be an acceptable JavaScript type and type of array should be exactly Object[], not SomeObjectSubclass[].

Returns:
the new array object.


newArray

public final Scriptable newArray(Scriptable scope,
                                 int length)
Create an array with a specified initial length.

Parameters:
scope - the scope to create the object in
length - the initial length (JavaScript arrays may have additional properties added dynamically).

Returns:
the new array object


newObject

public final Scriptable newObject(Scriptable scope)
            throws EvaluatorException,
                   JavaScriptException
Create a new JavaScript object. Equivalent to evaluating "new Object()".

Parameters:
scope - the scope to search for the constructor and to evaluate against

Returns:
the new object

Throws:
EvaluatorException - if "Object" cannot be found in the scope or is not a function
JavaScriptException - if an uncaught JavaScript exception occurred while creating the object


newObject

public final Scriptable newObject(Scriptable scope,
                                  String constructorName)
            throws EvaluatorException,
                   JavaScriptException
Create a new JavaScript object by executing the named constructor. The call newObject(scope, "Foo") is equivalent to evaluating "new Foo()".

Parameters:
scope - the scope to search for the constructor and to evaluate against
constructorName - the name of the constructor to call

Returns:
the new object

Throws:
EvaluatorException - if a property with the constructor name cannot be found in the scope or is not a function
JavaScriptException - if an uncaught JavaScript exception occurred while creating the object


newObject

public final Scriptable newObject(Scriptable scope,
                                  String constructorName,
                                  Object[] args)
            throws EvaluatorException,
                   JavaScriptException
Creates a new JavaScript object by executing the named constructor. Searches scope for the named constructor, calls it with the given arguments, and returns the result.

The code

 Object[] args = { "a", "b" };
 newObject(scope, "Foo", args)
is equivalent to evaluating "new Foo('a', 'b')", assuming that the Foo constructor has been defined in scope.

Parameters:
scope - The scope to search for the constructor and to evaluate against
constructorName - the name of the constructor to call
args - the array of arguments for the constructor

Returns:
the new object

Throws:
EvaluatorException - if a property with the constructor name cannot be found in the scope or is not a function
JavaScriptException - if an uncaught JavaScript exception occurs while creating the object


putThreadLocal

public final void putThreadLocal(Object key,
                                 Object value)
Put a value that can later be retrieved using a given key.

Parameters:
key - the key used to index the value
value - the value to save


removeActivationName

public void removeActivationName(String name)
Remove a name from the list of names forcing the creation of real activation objects for functions.

Parameters:
name - the name of the object to remove from the list


removeContextListener

public static void removeContextListener(ContextListener listener)
Remove a Context listener.

Parameters:
listener - the listener to remove.


removePropertyChangeListener

public final void removePropertyChangeListener(PropertyChangeListener l)
Remove an object from the list of objects registered to receive notification of changes to a bounded property

Parameters:
l - the listener

See Also:
java.beans.PropertyChangeEvent, addPropertyChangeListener(java.beans.PropertyChangeListener)


removeThreadLocal

public final void removeThreadLocal(Object key)
Remove values from thread-local storage.

Parameters:
key - the key for the entry to remove.

Since:
1.5 release 2


reportError

public static void reportError(String message)
Report an error using the error reporter for the current thread.

Parameters:
message - the error message to report

See Also:
ErrorReporter


reportError

public static void reportError(String message,
                               String sourceName,
                               int lineno,
                               String lineSource,
                               int lineOffset)
Report an error using the error reporter for the current thread.

Parameters:
message - the error message to report
sourceName - a string describing the source, such as a filename
lineno - the starting line number
lineSource - the text of the line (may be null)
lineOffset - the offset into lineSource where problem was detected

See Also:
ErrorReporter


reportRuntimeError

public static EvaluatorException reportRuntimeError(String message)
Report a runtime error using the error reporter for the current thread.

Parameters:
message - the error message to report

See Also:
ErrorReporter


reportRuntimeError

public static EvaluatorException reportRuntimeError(String message,
                                                    String sourceName,
                                                    int lineno,
                                                    String lineSource,
                                                    int lineOffset)
Report a runtime error using the error reporter for the current thread.

Parameters:
message - the error message to report
sourceName - a string describing the source, such as a filename
lineno - the starting line number
lineSource - the text of the line (may be null)
lineOffset - the offset into lineSource where problem was detected

Returns:
a runtime exception that will be thrown to terminate the execution of the script

See Also:
ErrorReporter


reportWarning

public static void reportWarning(String message)
Report a warning using the error reporter for the current thread.

Parameters:
message - the warning message to report

See Also:
ErrorReporter


reportWarning

public static void reportWarning(String message,
                                 String sourceName,
                                 int lineno,
                                 String lineSource,
                                 int lineOffset)
Report a warning using the error reporter for the current thread.

Parameters:
message - the warning message to report
sourceName - a string describing the source, such as a filename
lineno - the starting line number
lineSource - the text of the line (may be null)
lineOffset - the offset into lineSource where problem was detected

See Also:
ErrorReporter


seal

public final void seal(Object sealKey)
Seal this Context object so any attempt to modify any of its properties including calling enter() and exit() methods will throw an exception.

If sealKey is not null, calling unseal(Object sealKey) with the same key unseals the object. If sealKey is null, unsealing is no longer possible.

See Also:
isSealed(), unseal(Object)


setApplicationClassLoader

public final void setApplicationClassLoader(ClassLoader loader)


setCachingEnabled

public static void setCachingEnabled(boolean cachingEnabled)

Deprecated. To enable/disable caching for a particular top scope, use ClassCache.get(Scriptable) and

ClassCache.setCachingEnabled(boolean). The function is kept only for compatibility and does nothing.


setClassShutter

public final void setClassShutter(ClassShutter shutter)
Set the LiveConnect access filter for this context.

ClassShutter may only be set if it is currently null. Otherwise a SecurityException is thrown.

Parameters:
shutter - a ClassShutter object


setCompileFunctionsWithDynamicScope

public final void setCompileFunctionsWithDynamicScope(boolean flag)
Set whether functions compiled by this context should use dynamic scope.

Parameters:
flag - if true, compile functions with dynamic scope

Since:
1.5 Release 1


setDebugger

public final void setDebugger(org.mozilla.javascript.debug.Debugger debugger,
                              Object contextData)
Set the associated debugger.

Parameters:
debugger - the debugger to be used on callbacks from the engine.
contextData - arbitrary object that debugger can use to store per Context data.


setErrorReporter

public final ErrorReporter setErrorReporter(ErrorReporter reporter)
Change the current error reporter.

Returns:
the previous error reporter

See Also:
ErrorReporter


setGeneratingDebug

public final void setGeneratingDebug(boolean generatingDebug)
Specify whether or not debug information should be generated.

Setting the generation of debug information on will set the optimization level to zero.

Since:
1.3


setGeneratingSource

public final void setGeneratingSource(boolean generatingSource)
Specify whether or not source information should be generated.

Without source information, evaluating the "toString" method on JavaScript functions produces only "[native code]" for the body of the function. Note that code generated without source is not fully ECMA conformant.

Since:
1.3


setInstructionObserverThreshold

public final void setInstructionObserverThreshold(int threshold)


setLanguageVersion

public void setLanguageVersion(int version)
Set the language version.

Setting the language version will affect functions and scripts compiled subsequently. See the overview documentation for version-specific behavior.

Parameters:
version - the version as specified by VERSION_1_0, VERSION_1_1, etc.


setLocale

public final Locale setLocale(Locale loc)
Set the current locale.

See Also:
java.util.Locale


setOptimizationLevel

public final void setOptimizationLevel(int optimizationLevel)
Set the current optimization level.

The optimization level is expected to be an integer between -1 and 9. Any negative values will be interpreted as -1, and any values greater than 9 will be interpreted as 9. An optimization level of -1 indicates that interpretive mode will always be used. Levels 0 through 9 indicate that class files may be generated. Higher optimization levels trade off compile time performance for runtime performance. The optimizer level can't be set greater than -1 if the optimizer package doesn't exist at run time.

Parameters:
optimizationLevel - an integer indicating the level of optimization to perform

Since:
1.3


setSecurityController

public final void setSecurityController(SecurityController controller)
Set the security controller for this context.

SecurityController may only be set if it is currently null. Otherwise a SecurityException is thrown.

Parameters:
controller - a SecurityController object


setWrapFactory

public final void setWrapFactory(WrapFactory wrapFactory)
Set a WrapFactory for this Context.

The WrapFactory allows custom object wrapping behavior for Java object manipulated with JavaScript.

Since:
1.5 Release 4

See Also:
WrapFactory


setWrapHandler

public final void setWrapHandler(org.mozilla.javascript.WrapHandler wrapHandler)

Deprecated. As of Rhino 1.5 Release 4, use


stringIsCompilableUnit

public final boolean stringIsCompilableUnit(String source)
Check whether a string is ready to be compiled.

stringIsCompilableUnit is intended to support interactive compilation of javascript. If compiling the string would result in an error that might be fixed by appending more source, this method returns false. In every other case, it returns true.

Interactive shells may accumulate source lines, using this method after each new line is appended to check whether the statement being entered is complete.

Parameters:
source - the source buffer to check

Returns:
whether the source is ready for compilation

Since:
1.4 Release 2


throwAsScriptRuntimeEx

public static RuntimeException throwAsScriptRuntimeEx(Throwable e)
Rethrow the exception wrapping it as the script runtime exception. Unless the exception is instance of EcmaError or EvaluatorException it will be wrapped as WrappedException, a subclass of EvaluatorException. The resulting exception object always contains source name and line number of script that triggered exception.

This method always throws an exception, its return value is provided only for convenience to allow a usage like:

 throw Context.throwAsScriptRuntimeEx(ex);
 
to indicate that code after the method is unreachable.


toBoolean

public static boolean toBoolean(Object value)
Convert the value to a JavaScript boolean value.

See ECMA 9.2.

Parameters:
value - a JavaScript value

Returns:
the corresponding boolean value converted using the ECMA rules


toNumber

public static double toNumber(Object value)
Convert the value to a JavaScript Number value.

Returns a Java double for the JavaScript Number.

See ECMA 9.3.

Parameters:
value - a JavaScript value

Returns:
the corresponding double value converted using the ECMA rules


toObject

public static Scriptable toObject(Object value,
                                  Scriptable scope)
Convert the value to an JavaScript object value.

Note that a scope must be provided to look up the constructors for Number, Boolean, and String.

See ECMA 9.9.

Additionally, arbitrary Java objects and classes will be wrapped in a Scriptable object with its Java fields and methods reflected as JavaScript properties of the object.

Parameters:
value - any Java object
scope - global scope containing constructors for Number, Boolean, and String

Returns:
new JavaScript object


toObject

public static Scriptable toObject(Object value,
                                  Scriptable scope,
                                  Class staticType)

Deprecated. Use toObject(Object,Scriptable) instead.


toString

public static String toString(Object value)
Convert the value to a JavaScript String value.

See ECMA 9.8.

Parameters:
value - a JavaScript value

Returns:
the corresponding String value converted using the ECMA rules


toType

public static Object toType(Object value,
                            Class desiredType)
            throws IllegalArgumentException
Convert a JavaScript value into the desired type. Uses the semantics defined with LiveConnect3 and throws an Illegal argument exception if the conversion cannot be performed.

Parameters:
value - the JavaScript value to convert
desiredType - the Java type to convert to. Primitive Java types are represented using the TYPE fields in the corresponding wrapper class in java.lang.

Returns:
the converted value


unseal

public final void unseal(Object sealKey)

See Also:
isSealed(), seal(Object sealKey)