org.helma.javascript
Class RhinoEngine

java.lang.Object
  org.helma.javascript.RhinoEngine

public class RhinoEngine
extends java.lang.Object

This class provides methods to create JavaScript objects from JavaScript files.

Author:

Hannes Wallnoefer

Field Summary

static java.lang.Object[]

EMPTY_ARGS

Constructor Summary

RhinoEngine(java.util.List<Repository> repositories)
Create a RhinoEngine which loads scripts from directory dir.

RhinoEngine(java.util.List<Repository> repositories, java.lang.Class[] classes)
Create a RhinoEngine which loads scripts from directory dir and defines the given classes as native host objects.

Method Summary

void	addCallback(java.lang.String event, java.lang.String name, org.mozilla.javascript.Function func) Register a callback.
org.mozilla.javascript.Scriptable	createThreadScope(org.mozilla.javascript.Context cx) Create the per-thread top level javascript scope.
void	defineHostClass(java.lang.Class clazz) Define a Javascript host object implemented by the given class.
java.lang.Object	evaluate(java.util.Map<java.lang.String,java.lang.Object> globals, java.lang.String path) Evaluate a module and return the result.
Repository	findRepository(java.lang.String path, Repository localPath)
Resource	findResource(java.lang.String path, Repository localPath) Search for a resource in a local path, or the main repository.
HelmaClassLoader	getClassLoader()
org.mozilla.javascript.ContextFactory	getContextFactory()
ExtendedJavaClass	getExtendedClass(java.lang.Class type)
protected Repository	getRepository(org.mozilla.javascript.Scriptable scope) Get the repository associated with the scope or one of its prototypes
Repository	getRepository(java.lang.String path) Get a resource from our script repository
Resource	getResource(java.lang.String path) Get a resource from our script repository
java.util.List<Resource>	getResources(java.lang.String path) Get a list of all child resources for the given path relative to our script repository.
ReloadableScript	getScript(java.lang.String moduleName) Resolves a type name to a script file within our script directory and returns a Scriptable evaluated to the file.
ReloadableScript	getScript(java.lang.String moduleName, Repository localPath) Resolves a type name to a script file within our script directory and returns a Scriptable evaluated to the file.
ModuleScope	getShellScope() Return a shell scope for interactive evaluation
org.mozilla.javascript.WrapFactory	getWrapFactory()
protected void	initGlobalsAndArguments(org.mozilla.javascript.Scriptable scope, java.util.Map<java.lang.String,java.lang.Object> globals, java.lang.Object[] args) Initialize and normalize the global variables and arguments on a thread scope.
java.lang.Object	invoke(java.util.Map<java.lang.String,java.lang.Object> globals, org.mozilla.javascript.Scriptable thisObj, org.mozilla.javascript.Function function, java.lang.Object[] args) Invoke a javascript function.
java.lang.Object	invoke(java.util.Map<java.lang.String,java.lang.Object> globals, java.lang.String path, java.lang.String method, java.lang.Object... args) Invoke a javascript function.
java.lang.Object	invokeCallback(java.lang.String event, java.lang.Object thisObj, java.lang.Object... args) Invoke a callback.
org.mozilla.javascript.Scriptable	loadModule(org.mozilla.javascript.Context cx, java.lang.String moduleName, org.mozilla.javascript.Scriptable parentScope, org.mozilla.javascript.Scriptable loadingScope) Load a Javascript module into a module scope.
void	removeCallback(java.lang.String event, java.lang.String name) Unregister a previously registered callback.
protected java.lang.Object	wrapArgument(java.lang.Object value, org.mozilla.javascript.Scriptable scope) Prepare a single property or argument value for use within rhino.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY_ARGS

public static final java.lang.Object[] EMPTY_ARGS

Constructor Detail

RhinoEngine

public RhinoEngine(java.util.List<Repository> repositories)

Create a RhinoEngine which loads scripts from directory dir.

Parameters:

repositories - a list of code repositories

RhinoEngine

public RhinoEngine(java.util.List<Repository> repositories,
                   java.lang.Class[] classes)

Create a RhinoEngine which loads scripts from directory dir and defines the given classes as native host objects.

Parameters:

repositories - a list of code repositories

classes - the host classes to define

Method Detail

defineHostClass

public void defineHostClass(java.lang.Class clazz)
                     throws java.lang.reflect.InvocationTargetException,
                            java.lang.InstantiationException,
                            java.lang.IllegalAccessException

Define a Javascript host object implemented by the given class.

Parameters:

clazz - The Java class implementing the host object.

Throws:

java.lang.IllegalAccessException - if access is not available to a reflected class member

java.lang.InstantiationException - if unable to instantiate the named class

java.lang.reflect.InvocationTargetException - if an exception is thrown during execution of methods of the named class

addCallback

public void addCallback(java.lang.String event,
                        java.lang.String name,
                        org.mozilla.javascript.Function func)

Register a callback. Callbacks are javascript functions that can be invoked on certain events.

Parameters:

name - the callback name

func - the callback function

removeCallback

public void removeCallback(java.lang.String event,
                           java.lang.String name)

Unregister a previously registered callback.

Parameters:

name - the callback name

invokeCallback

public java.lang.Object invokeCallback(java.lang.String event,
                                       java.lang.Object thisObj,
                                       java.lang.Object... args)

Invoke a callback. If no callback is registered under this name fail silently.

Parameters:

event - the callback event

args - the arguments

Returns:

the return value

evaluate

public java.lang.Object evaluate(java.util.Map<java.lang.String,java.lang.Object> globals,
                                 java.lang.String path)
                          throws java.io.IOException

Evaluate a module and return the result.

Parameters:

globals - a map of global variables

path - the path of the module to evaluate

Returns:

the return value of the evaluation

Throws:

java.io.IOException - if an I/O related error occurred

invoke

public java.lang.Object invoke(java.util.Map<java.lang.String,java.lang.Object> globals,
                               java.lang.String path,
                               java.lang.String method,
                               java.lang.Object... args)
                        throws java.io.IOException,
                               java.lang.NoSuchMethodException

Invoke a javascript function. This enters a JavaScript context, creates a new per-thread scope, calls the function, exits the context and returns the return value of the invocation.

Parameters:

globals - map of global variables to set in the thread scope

path - the file path to the script

method - the method name to call in the script

args - the arguments to pass to the method

Returns:

the return value of the invocation

Throws:

java.lang.NoSuchMethodException - the method is not defined

java.io.IOException - an I/O related error occurred

getShellScope

public ModuleScope getShellScope()

Return a shell scope for interactive evaluation

Returns:

a shell scope

invoke

public java.lang.Object invoke(java.util.Map<java.lang.String,java.lang.Object> globals,
                               org.mozilla.javascript.Scriptable thisObj,
                               org.mozilla.javascript.Function function,
                               java.lang.Object[] args)
                        throws java.io.IOException,
                               java.lang.NoSuchMethodException

Invoke a javascript function. This enters a JavaScript context, creates a new per-thread scope, calls the function, exits the context and returns the return value of the invocation.

Parameters:

globals - map of global variables to set in the thread scope

thisObj - the object to invoke the function on

function - the function object to invoke

args - the arguments to pass to the method

Returns:

the return value of the invocation

Throws:

java.lang.NoSuchMethodException - the method is not defined

java.io.IOException - an I/O related error occurred

createThreadScope

public org.mozilla.javascript.Scriptable createThreadScope(org.mozilla.javascript.Context cx)

Create the per-thread top level javascript scope. This has the global shared scope as prototype, and serves as prototype for the module scopes loaded by this thread.

Parameters:

cx - the current context

Returns:

the scope object

initGlobalsAndArguments

protected void initGlobalsAndArguments(org.mozilla.javascript.Scriptable scope,
                                       java.util.Map<java.lang.String,java.lang.Object> globals,
                                       java.lang.Object[] args)

Initialize and normalize the global variables and arguments on a thread scope.

Parameters:

scope - the thread local scope

globals - the map of global objects

args - the arguments

wrapArgument

protected java.lang.Object wrapArgument(java.lang.Object value,
                                        org.mozilla.javascript.Scriptable scope)

Prepare a single property or argument value for use within rhino.

Parameters:

value - the property or argument value

scope - the scope

Returns:

the object wrapped and wired for rhino

getScript

public ReloadableScript getScript(java.lang.String moduleName)
                           throws org.mozilla.javascript.JavaScriptException,
                                  java.io.IOException

Resolves a type name to a script file within our script directory and returns a Scriptable evaluated to the file.

Parameters:

moduleName - the name of the module to load

Returns:

The raw compiled script for the module

Throws:

org.mozilla.javascript.JavaScriptException - if an error occurred evaluating the script file

java.io.IOException - if an error occurred reading the script file

getScript

public ReloadableScript getScript(java.lang.String moduleName,
                                  Repository localPath)
                           throws org.mozilla.javascript.JavaScriptException,
                                  java.io.IOException

Resolves a type name to a script file within our script directory and returns a Scriptable evaluated to the file.

Parameters:

moduleName - the name of the module to load

localPath - the path of the resource issuing this call

Returns:

The raw compiled script for the module

Throws:

org.mozilla.javascript.JavaScriptException - if an error occurred evaluating the script file

java.io.IOException - if an error occurred reading the script file

loadModule

public org.mozilla.javascript.Scriptable loadModule(org.mozilla.javascript.Context cx,
                                                    java.lang.String moduleName,
                                                    org.mozilla.javascript.Scriptable parentScope,
                                                    org.mozilla.javascript.Scriptable loadingScope)
                                             throws java.io.IOException

Load a Javascript module into a module scope. This checks if the module has already been loaded in the current context and if so returns the existing module scope.

Parameters:

cx - the current context

moduleName - the module name

parentScope - the parent scope to load the module

loadingScope - the scope requesting the module

Returns:

the loaded module scope

Throws:

java.io.IOException - indicates that in input/output related error occurred

getRepository

protected Repository getRepository(org.mozilla.javascript.Scriptable scope)

Get the repository associated with the scope or one of its prototypes

Parameters:

scope - the scope to get the repository from

Returns:

the repository, or null

getResource

public Resource getResource(java.lang.String path)

Get a resource from our script repository

Parameters:

path - the resource path

Returns:

the resource

getRepository

public Repository getRepository(java.lang.String path)

Get a resource from our script repository

Parameters:

path - the resource path

Returns:

the resource

getResources

public java.util.List<Resource> getResources(java.lang.String path)

Get a list of all child resources for the given path relative to our script repository.

Parameters:

path - the repository path

Returns:

a list of all nested child resources

findResource

public Resource findResource(java.lang.String path,
                             Repository localPath)

Search for a resource in a local path, or the main repository.

Parameters:

path - the resource name

localPath - a repository to look first

Returns:

the resource

findRepository

public Repository findRepository(java.lang.String path,
                                 Repository localPath)

getContextFactory

public org.mozilla.javascript.ContextFactory getContextFactory()

getClassLoader

public HelmaClassLoader getClassLoader()

getWrapFactory

public org.mozilla.javascript.WrapFactory getWrapFactory()

getExtendedClass

public ExtendedJavaClass getExtendedClass(java.lang.Class type)