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 call(ContextAction) or enter() methods.

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_DYNAMIC_SCOPE
Control if dynamic scope should be used for name access.
static int
FEATURE_E4X
Control if support for E4X(ECMAScript for XML) extension is available.
static int
FEATURE_ENHANCED_JAVA_ACCESS
Enables enhanced access to Java.
static int
FEATURE_LOCATION_INFORMATION_IN_ERROR
When the feature is on Rhino will add a "fileName" and "lineNumber" properties to Error objects automatically.
static int
FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME
Control if member expression as function name extension is available.
static int
FEATURE_NON_ECMA_GET_YEAR
Controls behaviour of Date.prototype.getYear().
static int
FEATURE_PARENT_PROTO_PROPERTIES
Control if properties __proto__ and __parent__ are treated specially.
static int
FEATURE_PARENT_PROTO_PROPRTIES
Deprecated. In previous releases, this name was given to FEATURE_PARENT_PROTO_PROPERTIES.
static int
FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER
Control if reserved keywords are treated as identifiers.
static int
FEATURE_STRICT_EVAL
Control if strict eval mode is enabled.
static int
FEATURE_STRICT_MODE
Controls whether JS 1.5 'strict mode' is enabled.
static int
FEATURE_STRICT_VARS
Control if strict variable mode is enabled.
static int
FEATURE_TO_STRING_AS_SOURCE
Control if toString() should returns the same result as toSource() when applied to objects and arrays.
static int
FEATURE_WARNING_AS_ERROR
Controls whether a warning should be treated as an error.
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_1_6
JavaScript 1.6
static int
VERSION_1_7
JavaScript 1.7
static int
VERSION_DEFAULT
The default version.
static int
VERSION_UNKNOWN
The unknown version.
static Object[]
emptyArgs
Convenient value to use as zero-length array of objects.
static String
errorReporterProperty
boolean
generateObserverCount
static String
languageVersionProperty

Constructor Summary

Context()
Deprecated. this constructor is deprecated because it creates a dependency on a static singleton context factory.
Context(ContextFactory factory)
Creates 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)
Deprecated.
void
addPropertyChangeListener(PropertyChangeListener l)
Register an object to receive notifications when a bound property has changed
static Object
call(ContextAction action)
Deprecated. use ContextFactory.call(ContextAction) instead as this method relies on usage of a static singleton "global" ContextFactory.
static Object
call(ContextFactory factory, 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.
Object
callFunctionWithContinuations(Callable function, Scriptable scope, Object[] args)
Call function that may pause execution by capturing a continuation.
ContinuationPending
captureContinuation()
Capture a continuation from the current execution.
static void
checkLanguageVersion(int version)
static void
checkOptimizationLevel(int optimizationLevel)
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.
Script
compileString(String source, String sourceName, int lineno, Object securityDomain)
Compiles the source in the given string.
GeneratedClassLoader
createClassLoader(ClassLoader parent)
Create class loader for generated classes.
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, int indent)
Decompile the script.
static Context
enter()
Same as calling ContextFactory.enterContext() on the global ContextFactory instance.
static Context
enter(Context cx)
Deprecated. use ContextFactory.enterContext(Context) instead as this method relies on usage of a static singleton "global" ContextFactory.
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.
Object
executeScriptWithContinuations(Script script, Scriptable scope)
Execute script that may pause execution by capturing a continuation.
static void
exit()
Exit a block of code requiring a Context.
ClassLoader
getApplicationClassLoader()
static Context
getCurrentContext()
Get the current Context.
static DebuggableScript
getDebuggableView(Script script)
Return DebuggableScript instance if any associated with the script.
Debugger
getDebugger()
Return the current debugger.
Object
getDebuggerContextData()
Return the debugger context data associated with current context.
XMLLib.Factory
getE4xImplementationFactory()
Returns an object which specifies an E4X implementation to use within this Context.
Object[]
getElements(Scriptable object)
Get the elements of a JavaScript array.
ErrorReporter
getErrorReporter()
Get the current error reporter.
ContextFactory
getFactory()
Return ContextFactory instance used to create this Context.
String
getImplementationVersion()
Get the implementation version.
int
getInstructionObserverThreshold()
Get threshold of executed instructions counter that triggers call to observeInstructionCount().
int
getLanguageVersion()
Get the current language version.
Locale
getLocale()
Get the current locale.
int
getMaximumInterpreterStackDepth()
Returns the maximum stack depth (in terms of number of call frames) allowed in a single invocation of interpreter.
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 WrapFactory, or null if none is defined.
boolean
hasCompileFunctionsWithDynamicScope()
Deprecated.
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 boolean
isValidLanguageVersion(int version)
static boolean
isValidOptimizationLevel(int optimizationLevel)
static Object
javaToJS(Object value, Scriptable scope)
Convenient method to convert java value to its closest representation in JavaScript.
static Object
jsToJava(Object value, Class desiredType)
Convert a JavaScript value into the desired type.
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.
protected void
observeInstructionCount(int instructionCount)
Allow application to monitor counter of executed script instructions in Context subclasses.
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)
Deprecated.
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.
static void
reportWarning(String message, Throwable t)
Object
resumeContinuation(Object continuation, Scriptable scope, Object functionResult)
Restarts execution of the JavaScript suspended at the call to captureContinuation().
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.
void
setClassShutter(ClassShutter shutter)
Set the LiveConnect access filter for this context.
void
setCompileFunctionsWithDynamicScope(boolean flag)
Deprecated.
void
setDebugger(Debugger debugger, Object contextData)
Set the associated debugger.
ErrorReporter
setErrorReporter(ErrorReporter reporter)
Change the current error reporter.
void
setGenerateObserverCount(boolean generateObserverCount)
Turn on or off generation of code with callbacks to track the count of executed instructions.
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)
Set threshold of executed instructions counter that triggers call to observeInstructionCount().
void
setLanguageVersion(int version)
Set the language version.
Locale
setLocale(Locale loc)
Set the current locale.
void
setMaximumInterpreterStackDepth(int max)
Sets the maximum stack depth (in terms of number of call frames) allowed in a single invocation of interpreter.
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.
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.
static String
toString(Object value)
Convert the value to a JavaScript String value.
static Object
toType(Object value, Class desiredType)
Deprecated.
void
unseal(Object sealKey)
Unseal previously sealed Context object.

Field Details

FEATURE_DYNAMIC_SCOPE

public static final int FEATURE_DYNAMIC_SCOPE
Field Value:
7
Since:
1.6 Release 1

FEATURE_E4X

public static final int FEATURE_E4X
Field Value:
6
Since:
1.6 Release 1

FEATURE_ENHANCED_JAVA_ACCESS

public static final int FEATURE_ENHANCED_JAVA_ACCESS
Field Value:
13
Since:
1.7 Release 1

FEATURE_LOCATION_INFORMATION_IN_ERROR

public static final int FEATURE_LOCATION_INFORMATION_IN_ERROR
Field Value:
10
Since:
1.6 Release 6

FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME

public static final int FEATURE_MEMBER_EXPR_AS_FUNCTION_NAME
Field Value:
2

FEATURE_NON_ECMA_GET_YEAR

public static final int FEATURE_NON_ECMA_GET_YEAR
Field Value:
1

FEATURE_PARENT_PROTO_PROPERTIES

public static final int FEATURE_PARENT_PROTO_PROPERTIES
Field Value:
5

FEATURE_PARENT_PROTO_PROPRTIES

public static final int FEATURE_PARENT_PROTO_PROPRTIES

Deprecated. In previous releases, this name was given to FEATURE_PARENT_PROTO_PROPERTIES.

Field Value:
5

FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER

public static final int FEATURE_RESERVED_KEYWORD_AS_IDENTIFIER
Field Value:
3

FEATURE_STRICT_EVAL

public static final int FEATURE_STRICT_EVAL
Field Value:
9
Since:
1.6 Release 1

FEATURE_STRICT_MODE

public static final int FEATURE_STRICT_MODE
Field Value:
11
Since:
1.6 Release 6

FEATURE_STRICT_VARS

public static final int FEATURE_STRICT_VARS
Field Value:
8
Since:
1.6 Release 1

FEATURE_TO_STRING_AS_SOURCE

public static final int FEATURE_TO_STRING_AS_SOURCE
Field Value:
4

FEATURE_WARNING_AS_ERROR

public static final int FEATURE_WARNING_AS_ERROR
Controls whether a warning should be treated as an error.
Field Value:
12
Since:
1.6 Release 6

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_1_6

public static final int VERSION_1_6
JavaScript 1.6
Field Value:
160

VERSION_1_7

public static final int VERSION_1_7
JavaScript 1.7
Field Value:
170

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
Convenient value to use as zero-length array of objects.

errorReporterProperty

public static final String errorReporterProperty

generateObserverCount

public boolean generateObserverCount

languageVersionProperty

public static final String languageVersionProperty

Constructor Details

Context

public Context()

Deprecated. this constructor is deprecated because it creates a dependency on a static singleton context factory. Use ContextFactory.enter() or ContextFactory.call(ContextAction) instead. If you subclass this class, consider using Context(ContextFactory) constructor instead in the subclasses' constructors.

Creates a new Context. The context will be associated with the global context factory. Note that the Context must be associated with a thread before it can be used to execute a script.

Context

protected Context(ContextFactory factory)
Creates a new context. Provided as a preferred super constructor for subclasses in place of the deprecated default public constructor.
Parameters:
factory - the context factory associated with this context (most likely, the one that created the context). Can not be null. The context features are inherited from the factory, and the context will also otherwise use its factory's services.

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)

Deprecated.


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(ContextAction action)

Deprecated. use ContextFactory.call(ContextAction) instead as this method relies on usage of a static singleton "global" ContextFactory.

Call ContextAction.run(Context cx) using the Context instance associated with the current thread. If no Context is associated with the thread, then ContextFactory.getGlobal().makeContext() will be called to construct new Context instance. The instance will be temporary associated with the thread during call to ContextAction.run(Context).
Returns:
The result of ContextAction.run(Context).

call

public static Object call(ContextFactory factory,
                          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. If no Context is associated with the thread, then ContextFactory.makeContext() will be called to construct new Context instance. The instance will be temporary associated with the thread during call to ContextAction.run(Context).

It is allowed but not advisable to use null for factory argument in which case the global static singleton ContextFactory instance will be used to create new context instances.


callFunctionWithContinuations

public Object callFunctionWithContinuations(Callable function,
                                            Scriptable scope,
                                            Object[] args)
            throws ContinuationPending
Call function that may pause execution by capturing a continuation. Caller must be prepared to catch a ContinuationPending exception and resume execution by calling resumeContinuation(Object,Scriptable,Object).
Parameters:
function - The function to call. The function must have been compiled with interpreted mode (optimization level -1)
scope - The scope to execute the script against
args - The arguments for the function
Throws:
ContinuationPending - if the script calls a function that results in a call to captureContinuation()
Since:
1.7 Release 2

captureContinuation

public ContinuationPending captureContinuation()
Capture a continuation from the current execution. The execution must have been started via a call to executeScriptWithContinuations(Script,Scriptable) or callFunctionWithContinuations(Callable,Scriptable,Object[]). This implies that the code calling this method must have been called as a function from the JavaScript script. Also, there cannot be any non-JavaScript code between the JavaScript frames (e.g., a call to eval()). The ContinuationPending exception returned must be thrown.
Returns:
A ContinuationPending exception that must be thrown
Since:
1.7 Release 2

checkLanguageVersion

public static void checkLanguageVersion(int version)

checkOptimizationLevel

public static void checkOptimizationLevel(int optimizationLevel)

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.

See Also:
compileReader(Reader in, String sourceName, int lineno, Object securityDomain)

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 GeneratedClassLoader createClassLoader(ClassLoader parent)
Create class loader for generated classes. The method calls ContextFactory.createClassLoader(ClassLoader) using the result of getFactory().

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,
                                    int indent)
Decompile the script.

The canonical source of the script is returned.

Parameters:
script - the script to decompile
indent - the number of spaces to indent the result
Returns:
a string representing the script source

enter

public static Context enter()
Same as calling ContextFactory.enterContext() on the global ContextFactory instance.
Returns:
a Context associated with the current thread

enter

public static Context enter(Context cx)

Deprecated. use ContextFactory.enterContext(Context) instead as this method relies on usage of a static singleton "global" ContextFactory.

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
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

evaluateString

public final Object evaluateString(Scriptable scope,
                                   String source,
                                   String sourceName,
                                   int lineno,
                                   Object securityDomain)
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

executeScriptWithContinuations

public Object executeScriptWithContinuations(Script script,
                                             Scriptable scope)
            throws ContinuationPending
Execute script that may pause execution by capturing a continuation. Caller must be prepared to catch a ContinuationPending exception and resume execution by calling resumeContinuation(Object,Scriptable,Object).
Parameters:
script - The script to execute. Script must have been compiled with interpreted mode (optimization level -1)
scope - The scope to execute the script against
Throws:
ContinuationPending - if the script calls a function that results in a call to captureContinuation()
Since:
1.7 Release 2

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 ContextFactory.enterContext() 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.

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.

getDebuggableView

public static DebuggableScript getDebuggableView(Script script)
Return DebuggableScript instance if any associated with the script. If callable supports DebuggableScript implementation, the method returns it. Otherwise null is returned.

getDebugger

public final 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

getE4xImplementationFactory

public XMLLib.Factory getE4xImplementationFactory()
Returns an object which specifies an E4X implementation to use within this Context. Note that the XMLLib.Factory interface should be considered experimental. The default implementation uses the implementation provided by this Context's ContextFactory.
Returns:
An XMLLib.Factory. Should not return null if FEATURE_E4X is enabled. See hasFeature(int).

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

getFactory

public final ContextFactory getFactory()
Return ContextFactory instance used to create this Context.

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 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

getMaximumInterpreterStackDepth

public final int getMaximumInterpreterStackDepth()
Returns the maximum stack depth (in terms of number of call frames) allowed in a single invocation of interpreter. If the set depth would be exceeded, the interpreter will throw an EvaluatorException in the script. Defaults to Integer.MAX_VALUE. The setting only has effect for interpreted functions (those compiled with optimization level set to -1). As the interpreter doesn't use the Java stack but rather manages its own stack in the heap memory, a runaway recursion in interpreted code would eventually consume all available memory and cause OutOfMemoryError instead of a StackOverflowError limited to only a single thread. This setting helps prevent such situations.
Returns:
The current maximum interpreter stack depth.

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 retrieved. 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 WrapFactory, or null if none is defined.
Since:
1.5 Release 4
See Also:
WrapFactory

hasCompileFunctionsWithDynamicScope

public final boolean hasCompileFunctionsWithDynamicScope()

Deprecated.


hasFeature

public boolean hasFeature(int featureIndex)
Parameters:
featureIndex - feature index to check
Returns:
true if the featureIndex feature is turned on

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)

isValidLanguageVersion

public static boolean isValidLanguageVersion(int version)

isValidOptimizationLevel

public static boolean isValidOptimizationLevel(int optimizationLevel)

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.

jsToJava

public static Object jsToJava(Object value,
                              Class desiredType)
            throws EvaluatorException
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
Throws:
EvaluatorException - if the conversion cannot be performed

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)
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

newObject

public final Scriptable newObject(Scriptable scope,
                                  String constructorName)
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

newObject

public final Scriptable newObject(Scriptable scope,
                                  String constructorName,
                                  Object[] args)
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

observeInstructionCount

protected void observeInstructionCount(int instructionCount)
Allow application to monitor counter of executed script instructions in Context subclasses. Run-time calls this when instruction counting is enabled and the counter reaches limit set by setInstructionObserverThreshold(). The method is useful to observe long running scripts and if necessary to terminate them.

The default implementation calls ContextFactory.observeInstructionCount(Context cx, int instructionCount) that allows to customize Context behavior without introducing Context subclasses.

Parameters:
instructionCount - amount of script instruction executed since last call to observeInstructionCount

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)

Deprecated.


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

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

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

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

reportWarning

public static void reportWarning(String message,
                                 Throwable t)

resumeContinuation

public Object resumeContinuation(Object continuation,
                                 Scriptable scope,
                                 Object functionResult)
            throws ContinuationPending
Restarts execution of the JavaScript suspended at the call to captureContinuation(). Execution of the code will resume with the functionResult as the result of the call that captured the continuation. Execution of the script will either conclude normally and the result returned, another continuation will be captured and thrown, or the script will terminate abnormally and throw an exception.
Parameters:
continuation - The value returned by ContinuationPending.getContinuation()
functionResult - This value will appear to the code being resumed as the result of the function that captured the continuation
Throws:
ContinuationPending - if another continuation is captured before the code terminates
Since:
1.7 Release 2

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.


setApplicationClassLoader

public final void setApplicationClassLoader(ClassLoader loader)

setCachingEnabled

public static void setCachingEnabled(boolean cachingEnabled)

Deprecated.


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)

Deprecated.


setDebugger

public final void setDebugger(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

setGenerateObserverCount

public void setGenerateObserverCount(boolean generateObserverCount)
Turn on or off generation of code with callbacks to track the count of executed instructions. Currently only affects JVM byte code generation: this slows down the generated code, but code generated without the callbacks will not be counted toward instruction thresholds. Rhino's interpretive mode does instruction counting without inserting callbacks, so there is no requirement to compile code differently.
Parameters:
generateObserverCount - if true, generated code will contain calls to accumulate an estimate of the instructions executed.

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)
Parameters:
threshold - The instruction 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

setMaximumInterpreterStackDepth

public final void setMaximumInterpreterStackDepth(int max)
Sets the maximum stack depth (in terms of number of call frames) allowed in a single invocation of interpreter. If the set depth would be exceeded, the interpreter will throw an EvaluatorException in the script. Defaults to Integer.MAX_VALUE. The setting only has effect for interpreted functions (those compiled with optimization level set to -1). As the interpreter doesn't use the Java stack but rather manages its own stack in the heap memory, a runaway recursion in interpreted code would eventually consume all available memory and cause OutOfMemoryError instead of a StackOverflowError limited to only a single thread. This setting helps prevent such situations.
Parameters:
max - the new maximum interpreter stack depth

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 and SecurityController.hasGlobal() is false. Otherwise a SecurityException is thrown.

Parameters:
controller - a SecurityController object
See Also:
SecurityController.initGlobal(SecurityController controller), SecurityController.hasGlobal()

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

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.


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

Deprecated.

See Also:
jsToJava(Object, Class)

unseal

public final void unseal(Object sealKey)
See Also:
isSealed(), seal(Object sealKey)