mylar/lib/js2py/constructors/jsobject.py

from ..base import *
import six

#todo Double check everything is OK

@Js
def Object():
    val = arguments.get('0')
    if val.is_null() or val.is_undefined():
        return PyJsObject(prototype=ObjectPrototype)
    return val.to_object()


@Js
def object_constructor():
    if len(arguments):
        val = arguments.get('0')
        if val.TYPE=='Object':
            #Implementation dependent, but my will simply return :)
            return val
        elif val.TYPE in {'Number', 'String', 'Boolean'}:
            return val.to_object()
    return PyJsObject(prototype=ObjectPrototype)

Object.create = object_constructor
Object.own['length']['value'] = Js(1)


class ObjectMethods:
    def getPrototypeOf(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.getPrototypeOf called on non-object')
        return null if obj.prototype is None else obj.prototype

    def getOwnPropertyDescriptor (obj, prop):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.getOwnPropertyDescriptor called on non-object')
        return obj.own.get(prop.to_string().value) # will return undefined if we dont have this prop

    def getOwnPropertyNames(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.getOwnPropertyDescriptor called on non-object')
        return obj.own.keys()

    def create(obj):
        if not (obj.is_object() or obj.is_null()):
            raise MakeError('TypeError', 'Object prototype may only be an Object or null')
        temp = PyJsObject(prototype=(None if obj.is_null() else obj))
        if len(arguments)>1 and not arguments[1].is_undefined():
            if six.PY2:
                ObjectMethods.defineProperties.__func__(temp, arguments[1])
            else:
                ObjectMethods.defineProperties(temp, arguments[1])
        return temp

    def defineProperty(obj, prop, attrs):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.defineProperty called on non-object')
        name = prop.to_string().value
        if not obj.define_own_property(name, ToPropertyDescriptor(attrs)):
            raise MakeError('TypeError', 'Cannot redefine property: %s' % name)
        return obj

    def defineProperties(obj, properties):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.defineProperties called on non-object')
        props = properties.to_object()
        for name in props:
            desc = ToPropertyDescriptor(props.get(name.value))
            if not obj.define_own_property(name.value, desc):
                raise MakeError('TypeError', 'Failed to define own property: %s'%name.value)
        return obj

    def seal(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.seal called on non-object')
        for desc in obj.own.values():
            desc['configurable'] = False
        obj.extensible = False
        return obj

    def freeze(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.freeze called on non-object')
        for desc in obj.own.values():
            desc['configurable'] = False
            if is_data_descriptor(desc):
                desc['writable'] = False
        obj.extensible = False
        return obj

    def preventExtensions(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.preventExtensions on non-object')
        obj.extensible = False
        return obj

    def isSealed(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.isSealed called on non-object')
        if obj.extensible:
            return False
        for desc in obj.own.values():
            if desc['configurable']:
                return False
        return True

    def isFrozen(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.isFrozen called on non-object')
        if obj.extensible:
            return False
        for desc in obj.own.values():
            if desc['configurable']:
                return False
            if is_data_descriptor(desc) and desc['writable']:
                return False
        return True

    def isExtensible(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.isExtensible called on non-object')
        return obj.extensible

    def keys(obj):
        if not obj.is_object():
            raise MakeError('TypeError', 'Object.keys called on non-object')
        return [e for e,d in six.iteritems(obj.own) if d.get('enumerable')]


# add methods attached to Object constructor
fill_prototype(Object, ObjectMethods, default_attrs)
# add constructor to prototype
fill_in_props(ObjectPrototype, {'constructor':Object}, default_attrs)
# add prototype property to the constructor.
Object.define_own_property('prototype', {'value': ObjectPrototype,
                                         'enumerable': False,
                                         'writable': False,
                                         'configurable': False})



# some utility functions:

def ToPropertyDescriptor(obj):  # page 38 (50 absolute)
    if obj.TYPE!='Object':
        raise MakeError('TypeError', 'Can\'t convert non-object to property descriptor')
    desc = {}
    if obj.has_property('enumerable'):
        desc['enumerable'] = obj.get('enumerable').to_boolean().value
    if obj.has_property('configurable'):
        desc['configurable'] = obj.get('configurable').to_boolean().value
    if obj.has_property('value'):
        desc['value'] = obj.get('value')
    if obj.has_property('writable'):
        desc['writable'] = obj.get('writable').to_boolean().value
    if obj.has_property('get'):
        cand =  obj.get('get')
        if not (cand.is_undefined() or cand.is_callable()):
            raise MakeError('TypeError', 'Invalid getter (it has to be a function or undefined)')
        desc['get'] = cand
    if obj.has_property('set'):
        cand =  obj.get('set')
        if not (cand.is_undefined() or cand.is_callable()):
            raise MakeError('TypeError', 'Invalid setter (it has to be a function or undefined)')
        desc['set'] = cand
    if ('get' in desc or 'set' in desc) and ('value' in desc or 'writable' in desc):
        raise MakeError('TypeError', 'Invalid property.  A property cannot both have accessors and be writable or have a value.')
    return desc