org.ringojs.util

Class ScriptUtils

java.lang.Object

org.ringojs.util.ScriptUtils

public class ScriptUtils
extends Object

A collection of Rhino utility methods.

Constructor Summary

Constructors

Constructor and Description
ScriptUtils()

Method Summary

Modifier and Type	Method and Description
static void	assertHelper(Object condition, Object... args) Helper for console.assert().
static void	checkArguments(Object[] args, int min, int max) Make sure that number of arguments is valid.
static org.mozilla.javascript.Scriptable	getClassOrObjectProto(org.mozilla.javascript.Scriptable scope, String className) Return a class prototype, or the object prototype if the class is not defined.
static Map	getMapArgument(Object[] args, int pos, boolean allowNull) Get an argument as Map
static Object	getObjectArgument(Object[] args, int pos, boolean allowNull) Get an argument as object
static org.mozilla.javascript.ScriptableObject	getScriptableArgument(Object[] args, int pos, boolean allowNull) Get an argument as ScriptableObject
static String	getStringArgument(Object[] args, int pos, boolean allowNull) Get an argument as string
static Object	javaToJS(Object obj, org.mozilla.javascript.Scriptable scope) Coerce/wrap a java object to a JS object, and mask Lists and Maps as native JS objects.
static Object	jsToJava(Object obj) Unwrap a JS object to a java object.
static int	toInt(Object obj, int defaultValue) Try to convert an object to an int value, returning the default value if conversion fails.
static void	traceHelper(org.mozilla.javascript.Function function, Object... args) Get a snapshot of the current JavaScript evaluation state by creating an Error object and invoke the function on it passing along any arguments.

Methods inherited from class java.lang.Object

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

Constructor Detail

ScriptUtils

public ScriptUtils()

Method Detail

javaToJS

public static Object javaToJS(Object obj,
                              org.mozilla.javascript.Scriptable scope)

Coerce/wrap a java object to a JS object, and mask Lists and Maps as native JS objects.

Parameters:

obj - the object to coerce/wrap

scope - the scope

Returns:

the wrapped/masked java object

jsToJava

public static Object jsToJava(Object obj)

Unwrap a JS object to a java object. This is much more conservative than Context.jsToJava in that it will preserve undefined values.

Parameters:

obj - a JavaScript value

Returns:

a Java object corresponding to obj

getClassOrObjectProto

public static org.mozilla.javascript.Scriptable getClassOrObjectProto(org.mozilla.javascript.Scriptable scope,
                                                                      String className)

Return a class prototype, or the object prototype if the class is not defined.

Parameters:

scope - the scope

className - the class name

Returns:

the class or object prototype

checkArguments

public static void checkArguments(Object[] args,
                                  int min,
                                  int max)

Make sure that number of arguments is valid.

Parameters:

args - the argument array

min - the minimum number of arguments

max - the maximum number of arguments

Throws:

IllegalArgumentException - if the number of arguments is not valid

getScriptableArgument

public static org.mozilla.javascript.ScriptableObject getScriptableArgument(Object[] args,
                                                                            int pos,
                                                                            boolean allowNull)
                                                                     throws IllegalArgumentException

Get an argument as ScriptableObject

Parameters:

args - the argument array

pos - the position of the requested argument

Returns:

the argument as ScriptableObject

Throws:

IllegalArgumentException - if the argument can't be converted to a map

getStringArgument

public static String getStringArgument(Object[] args,
                                       int pos,
                                       boolean allowNull)

Get an argument as string

Parameters:

args - the argument array

pos - the position of the requested argument

Returns:

the argument as string

getMapArgument

public static Map getMapArgument(Object[] args,
                                 int pos,
                                 boolean allowNull)
                          throws IllegalArgumentException

Get an argument as Map

Parameters:

args - the argument array

pos - the position of the requested argument

Returns:

the argument as map

Throws:

IllegalArgumentException - if the argument can't be converted to a map

getObjectArgument

public static Object getObjectArgument(Object[] args,
                                       int pos,
                                       boolean allowNull)

Get an argument as object

Parameters:

args - the argument array

pos - the position of the requested argument

Returns:

the argument as object

toInt

public static int toInt(Object obj,
                        int defaultValue)

Try to convert an object to an int value, returning the default value if conversion fails.

Parameters:

obj - the value

defaultValue - the default value

Returns:

the converted value

traceHelper

public static void traceHelper(org.mozilla.javascript.Function function,
                               Object... args)

Get a snapshot of the current JavaScript evaluation state by creating an Error object and invoke the function on it passing along any arguments. Used to invoke console.trace() and friends because implementing this in JavaScript would mess with the evaluation state.

Parameters:

function - the function to call

args - optional arguments to pass to the function.

assertHelper

public static void assertHelper(Object condition,
                                Object... args)

Helper for console.assert(). Implemented in Java in order not to modify the JavaScript stack.

Parameters:

condition - the condition to test

args - one or more message parts