Files
tubestation/addon-sdk/source/lib/sdk/content/content-proxy.js

871 lines
28 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
/* Trick the linker in order to avoid error on `Components.interfaces` usage.
We are tricking the linker with `require('./content-proxy.js')` from
worjer.js in order to ensure shipping this file! But then the linker think
that this file is going to be used as a CommonJS module where we forbid usage
of `Components`.
*/
let Ci = Components['interfaces'];
/**
* Access key that allows privileged code to unwrap proxy wrappers through
* valueOf:
* let xpcWrapper = proxyWrapper.valueOf(UNWRAP_ACCESS_KEY);
* This key should only be used by proxy unit test.
*/
const UNWRAP_ACCESS_KEY = {};
/**
* Returns a closure that wraps arguments before calling the given function,
* which can be given to native functions that accept a function, such that when
* the closure is called, the given function is called with wrapped arguments.
*
* @param fun {Function}
* the function for which to create a closure wrapping its arguments
* @param obj {Object}
* target object from which `fun` comes from
* (optional, for debugging purpose)
* @param name {String}
* name of the attribute from which `fun` is binded on `obj`
* (optional, for debugging purpose)
*
* Example:
* function contentScriptListener(event) {}
* let wrapper = ContentScriptFunctionWrapper(contentScriptListener);
* xray.addEventListener("...", wrapper, false);
* -> Allow to `event` to be wrapped
*/
function ContentScriptFunctionWrapper(fun, obj, name) {
if ("___proxy" in fun && typeof fun.___proxy == "function")
return fun.___proxy;
let wrappedFun = function () {
let args = [];
for (let i = 0, l = arguments.length; i < l; i++)
args.push(wrap(arguments[i]));
//console.log("Called from native :"+obj+"."+name);
//console.log(">args "+arguments.length);
//console.log(fun);
// Native code can execute this callback with `this` being the wrapped
// function. For example, window.mozRequestAnimationFrame.
if (this == wrappedFun)
return fun.apply(fun, args);
return fun.apply(wrap(this), args);
};
Object.defineProperty(fun, "___proxy", {value : wrappedFun,
writable : false,
enumerable : false,
configurable : false});
return wrappedFun;
}
/**
* Returns a closure that unwraps arguments before calling the `fun` function,
* which can be used to build a wrapper for a native function that accepts
* wrapped arguments, since native function only accept unwrapped arguments.
*
* @param fun {Function}
* the function to wrap
* @param originalObject {Object}
* target object from which `fun` comes from
* (optional, for debugging purpose)
* @param name {String}
* name of the attribute from which `fun` is binded on `originalObject`
* (optional, for debugging purpose)
*
* Example:
* wrapper.appendChild = NativeFunctionWrapper(xray.appendChild, xray);
* wrapper.appendChild(anotherWrapper);
* -> Allow to call xray.appendChild with unwrapped version of anotherWrapper
*/
function NativeFunctionWrapper(fun, originalObject, name) {
return function () {
let args = [];
let obj = this && typeof this.valueOf == "function" ?
this.valueOf(UNWRAP_ACCESS_KEY) : this;
for (let i = 0, l = arguments.length; i < l; i++)
args.push( unwrap(arguments[i], obj, name) );
//if (name != "toString")
//console.log(">>calling native ["+(name?name:'#closure#')+"]: \n"+fun.apply+"\n"+obj+"\n("+args.join(', ')+")\nthis :"+obj+"from:"+originalObject+"\n");
// Need to use Function.prototype.apply.apply because XMLHttpRequest
// is a function (typeof return 'function') and fun.apply is null :/
let unwrapResult = Function.prototype.apply.apply(fun, [obj, args]);
let result = wrap(unwrapResult, obj, name);
//console.log("<< "+rr+" -> "+r);
return result;
};
}
/*
* Unwrap a JS value that comes from the content script.
* Mainly converts proxy wrapper to XPCNativeWrapper.
*/
function unwrap(value, obj, name) {
//console.log("unwrap : "+value+" ("+name+")");
if (!value)
return value;
let type = typeof value;
// In case of proxy, unwrap them recursively
// (it should not be recursive, just in case of)
if (["object", "function"].indexOf(type) !== -1 &&
"__isWrappedProxy" in value) {
while("__isWrappedProxy" in value)
value = value.valueOf(UNWRAP_ACCESS_KEY);
return value;
}
// In case of functions we need to return a wrapper that converts native
// arguments applied to this function into proxies.
if (type == "function")
return ContentScriptFunctionWrapper(value, obj, name);
// We must wrap objects coming from content script too, as they may have
// a function that will be called by a native method.
// For example:
// addEventListener(..., { handleEvent: function(event) {} }, ...);
if (type == "object")
return ContentScriptObjectWrapper(value);
if (["string", "number", "boolean"].indexOf(type) !== -1)
return value;
//console.log("return non-wrapped to native : "+typeof value+" -- "+value);
return value;
}
/**
* Returns an XrayWrapper proxy object that allow to wrap any of its function
* though `ContentScriptFunctionWrapper`. These proxies are given to
* XrayWrappers in order to automatically wrap values when they call a method
* of these proxies. So that they are only used internaly and content script,
* nor web page have ever access to them. As a conclusion, we can consider
* this code as being safe regarding web pages overload.
*
*
* @param obj {Object}
* object coming from content script context to wrap
*
* Example:
* let myListener = { handleEvent: function (event) {} };
* node.addEventListener("click", myListener, false);
* `event` has to be wrapped, so handleEvent has to be wrapped using
* `ContentScriptFunctionWrapper` function.
* In order to do so, we build this new kind of proxies.
*/
function ContentScriptObjectWrapper(obj) {
if ("___proxy" in obj && typeof obj.___proxy == "object")
return obj.___proxy;
function valueOf(key) {
if (key === UNWRAP_ACCESS_KEY)
return obj;
return this;
}
let proxy = Proxy.create({
// Fundamental traps
getPropertyDescriptor: function(name) {
return Object.getOwnPropertyDescriptor(obj, name);
},
defineProperty: function(name, desc) {
return Object.defineProperty(obj, name, desc);
},
getOwnPropertyNames: function () {
return Object.getOwnPropertyNames(obj);
},
delete: function(name) {
return delete obj[name];
},
// derived traps
has: function(name) {
return name === "__isXrayWrapperProxy" ||
name in obj;
},
hasOwn: function(name) {
return Object.prototype.hasOwnProperty.call(obj, name);
},
get: function(receiver, name) {
if (name == "valueOf")
return valueOf;
let value = obj[name];
if (!value)
return value;
return unwrap(value);
},
set: function(receiver, name, val) {
obj[name] = val;
return true;
},
enumerate: function() {
var result = [];
for each (let name in obj) {
result.push(name);
};
return result;
},
keys: function() {
return Object.keys(obj);
}
});
Object.defineProperty(obj, "___proxy", {value : proxy,
writable : false,
enumerable : false,
configurable : false});
return proxy;
}
// List of all existing typed arrays.
// Can be found here:
// http://mxr.mozilla.org/mozilla-central/source/js/src/jsapi.cpp#1790
const typedArraysCtor = [
ArrayBuffer,
Int8Array,
Uint8Array,
Int16Array,
Uint16Array,
Int32Array,
Uint32Array,
Float32Array,
Float64Array,
Uint8ClampedArray
];
/*
* Wrap a JS value coming from the document by building a proxy wrapper.
*/
function wrap(value, obj, name, debug) {
if (!value)
return value;
let type = typeof value;
if (type == "object") {
// Bug 671016: Typed arrays don't need to be proxified.
// We avoid checking the whole constructor list on all objects
// by doing this check only on non-extensible objects:
if (!Object.isExtensible(value) &&
typedArraysCtor.indexOf(value.constructor) !== -1)
return value;
// Bug 715755: do not proxify COW wrappers
// These wrappers throw an exception when trying to access
// any attribute that is not in a white list
try {
("nonExistantAttribute" in value);
}
catch(e) {
if (e.message.indexOf("Permission denied to access property") !== -1)
return value;
}
// We may have a XrayWrapper proxy.
// For example:
// let myListener = { handleEvent: function () {} };
// node.addEventListener("click", myListener, false);
// When native code want to call handleEvent,
// we go though ContentScriptFunctionWrapper that calls `wrap(this)`
// `this` is the XrayWrapper proxy of myListener.
// We return this object without building a CS proxy as it is already
// a value coming from the CS.
if ("__isXrayWrapperProxy" in value)
return value.valueOf(UNWRAP_ACCESS_KEY);
// Unwrap object before wrapping it.
// It should not happen with CS proxy objects.
while("__isWrappedProxy" in value) {
value = value.valueOf(UNWRAP_ACCESS_KEY);
}
if (XPCNativeWrapper.unwrap(value) !== value)
return getProxyForObject(value);
// In case of Event, HTMLCollection or NodeList or ???
// XPCNativeWrapper.unwrap(value) === value
// but it's still a XrayWrapper so let's build a proxy
return getProxyForObject(value);
}
if (type == "function") {
if (XPCNativeWrapper.unwrap(value) !== value
|| (typeof value.toString === "function" &&
value.toString().match(/\[native code\]/))) {
return getProxyForFunction(value, NativeFunctionWrapper(value, obj, name));
}
return value;
}
if (type == "string")
return value;
if (type == "number")
return value;
if (type == "boolean")
return value;
//console.log("return non-wrapped to wrapped : "+value);
return value;
}
/*
* Wrap an object from the document to a proxy wrapper
*/
function getProxyForObject(obj) {
if (typeof obj != "object") {
let msg = "tried to proxify something other than an object: " + typeof obj;
console.warn(msg);
throw msg;
}
if ("__isWrappedProxy" in obj) {
return obj;
}
// Check if there is a proxy cached on this wrapper,
// but take care of prototype ___proxy attribute inheritance!
if (obj && obj.___proxy && obj.___proxy.valueOf(UNWRAP_ACCESS_KEY) === obj) {
return obj.___proxy;
}
let proxy = Proxy.create(handlerMaker(obj));
Object.defineProperty(obj, "___proxy", {value : proxy,
writable : false,
enumerable : false,
configurable : false});
return proxy;
}
/*
* Wrap a function from the document to a proxy wrapper
*/
function getProxyForFunction(fun, callTrap) {
if (typeof fun != "function") {
let msg = "tried to proxify something other than a function: " + typeof fun;
console.warn(msg);
throw msg;
}
if ("__isWrappedProxy" in fun)
return obj;
if ("___proxy" in fun)
return fun.___proxy;
let proxy = Proxy.createFunction(handlerMaker(fun), callTrap);
Object.defineProperty(fun, "___proxy", {value : proxy,
writable : false,
enumerable : false,
configurable : false});
return proxy;
}
/*
* Check if a DOM attribute name is an event name.
*/
function isEventName(id) {
if (id.indexOf("on") != 0 || id.length == 2)
return false;
// Taken from:
// http://mxr.mozilla.org/mozilla-central/source/dom/base/nsDOMClassInfo.cpp#7616
switch (id[2]) {
case 'a' :
return (id == "onabort" ||
id == "onafterscriptexecute" ||
id == "onafterprint");
case 'b' :
return (id == "onbeforeunload" ||
id == "onbeforescriptexecute" ||
id == "onblur" ||
id == "onbeforeprint");
case 'c' :
return (id == "onchange" ||
id == "onclick" ||
id == "oncontextmenu" ||
id == "oncopy" ||
id == "oncut" ||
id == "oncanplay" ||
id == "oncanplaythrough");
case 'd' :
return (id == "ondblclick" ||
id == "ondrag" ||
id == "ondragend" ||
id == "ondragenter" ||
id == "ondragleave" ||
id == "ondragover" ||
id == "ondragstart" ||
id == "ondrop" ||
id == "ondurationchange");
case 'e' :
return (id == "onerror" ||
id == "onemptied" ||
id == "onended");
case 'f' :
return id == "onfocus";
case 'h' :
return id == "onhashchange";
case 'i' :
return (id == "oninput" ||
id == "oninvalid");
case 'k' :
return (id == "onkeydown" ||
id == "onkeypress" ||
id == "onkeyup");
case 'l' :
return (id == "onload" ||
id == "onloadeddata" ||
id == "onloadedmetadata" ||
id == "onloadstart");
case 'm' :
return (id == "onmousemove" ||
id == "onmouseout" ||
id == "onmouseover" ||
id == "onmouseup" ||
id == "onmousedown" ||
id == "onmessage");
case 'p' :
return (id == "onpaint" ||
id == "onpageshow" ||
id == "onpagehide" ||
id == "onpaste" ||
id == "onpopstate" ||
id == "onpause" ||
id == "onplay" ||
id == "onplaying" ||
id == "onprogress");
case 'r' :
return (id == "onreadystatechange" ||
id == "onreset" ||
id == "onresize" ||
id == "onratechange");
case 's' :
return (id == "onscroll" ||
id == "onselect" ||
id == "onsubmit" ||
id == "onseeked" ||
id == "onseeking" ||
id == "onstalled" ||
id == "onsuspend");
case 't':
return id == "ontimeupdate"
/*
// TODO: Make it work for mobile version
||
(nsDOMTouchEvent::PrefEnabled() &&
(id == "ontouchstart" ||
id == "ontouchend" ||
id == "ontouchmove" ||
id == "ontouchenter" ||
id == "ontouchleave" ||
id == "ontouchcancel"))*/;
case 'u' :
return id == "onunload";
case 'v':
return id == "onvolumechange";
case 'w':
return id == "onwaiting";
}
return false;
}
// XrayWrappers miss some attributes.
// Here is a list of functions that return a value when it detects a miss:
const NODES_INDEXED_BY_NAME = ["IMG", "FORM", "APPLET", "EMBED", "OBJECT"];
const xRayWrappersMissFixes = [
// Fix bug with XPCNativeWrapper on HTMLCollection
// We can only access array item once, then it's undefined :o
function (obj, name) {
let i = parseInt(name);
if (obj.toString().match(/HTMLCollection|NodeList/) &&
i >= 0 && i < obj.length) {
return wrap(XPCNativeWrapper(obj.wrappedJSObject[name]), obj, name);
}
return null;
},
// Trap access to document["form name"]
// that may refer to an existing form node
// http://mxr.mozilla.org/mozilla-central/source/dom/base/nsDOMClassInfo.cpp#9285
function (obj, name) {
if ("nodeType" in obj && obj.nodeType == 9) {
let node = obj.wrappedJSObject[name];
// List of supported tag:
// http://mxr.mozilla.org/mozilla-central/source/content/html/content/src/nsGenericHTMLElement.cpp#1267
if (node && NODES_INDEXED_BY_NAME.indexOf(node.tagName) != -1)
return wrap(XPCNativeWrapper(node));
}
return null;
},
// Trap access to window["frame name"] and window.frames[i]
// that refer to an (i)frame internal window object
// http://mxr.mozilla.org/mozilla-central/source/dom/base/nsDOMClassInfo.cpp#6824
function (obj, name) {
if (typeof obj == "object" && "document" in obj) {
// Ensure that we are on a window object
try {
obj.QueryInterface(Ci.nsIDOMWindow);
}
catch(e) {
return null;
}
// Integer case:
let i = parseInt(name);
if (i >= 0 && i in obj) {
return wrap(XPCNativeWrapper(obj[i]));
}
// String name case:
if (name in obj.wrappedJSObject) {
let win = obj.wrappedJSObject[name];
let nodes = obj.document.getElementsByName(name);
for (let i = 0, l = nodes.length; i < l; i++) {
let node = nodes[i];
if ("contentWindow" in node && node.contentWindow == win)
return wrap(node.contentWindow);
}
}
}
return null;
},
// Trap access to form["node name"]
// http://mxr.mozilla.org/mozilla-central/source/dom/base/nsDOMClassInfo.cpp#9477
function (obj, name) {
if (typeof obj == "object" && "tagName" in obj && obj.tagName == "FORM") {
let match = obj.wrappedJSObject[name];
let nodes = obj.ownerDocument.getElementsByName(name);
for (let i = 0, l = nodes.length; i < l; i++) {
let node = nodes[i];
if (node == match)
return wrap(node);
}
}
return null;
}
];
// XrayWrappers have some buggy methods.
// Here is the list of them with functions returning some replacement
// for a given object `obj`:
const xRayWrappersMethodsFixes = {
// postMessage method is checking the Javascript global
// and it expects it to be a window object.
// But in our case, the global object is our sandbox global object.
// See nsGlobalWindow::CallerInnerWindow():
// http://mxr.mozilla.org/mozilla-central/source/dom/base/nsGlobalWindow.cpp#5893
// nsCOMPtr<nsPIDOMWindow> win = do_QueryWrappedNative(wrapper);
// win is null
postMessage: function (obj) {
// Ensure that we are on a window object
try {
obj.QueryInterface(Ci.nsIDOMWindow);
}
catch(e) {
return null;
}
// Create a wrapper that is going to call `postMessage` through `eval`
let f = function postMessage(message, targetOrigin) {
let jscode = "this.postMessage(";
if (typeof message != "string")
jscode += JSON.stringify(message);
else
jscode += "'" + message.toString().replace(/['\\]/g,"\\$&") + "'";
targetOrigin = targetOrigin.toString().replace(/['\\]/g,"\\$&");
jscode += ", '" + targetOrigin + "')";
return this.wrappedJSObject.eval(jscode);
};
return getProxyForFunction(f, NativeFunctionWrapper(f));
},
// Fix mozMatchesSelector uses that is broken on XrayWrappers
// when we use document.documentElement.mozMatchesSelector.call(node, expr)
// It's only working if we call mozMatchesSelector on the node itself.
// SEE BUG 658909: mozMatchesSelector returns incorrect results with XrayWrappers
mozMatchesSelector: function (obj) {
// Ensure that we are on an object to expose this buggy method
try {
// Bug 707576 removed nsIDOMNSElement.
// Can be simplified as soon as Firefox 11 become the minversion
obj.QueryInterface("nsIDOMElement" in Ci ? Ci.nsIDOMElement :
Ci.nsIDOMNSElement);
}
catch(e) {
return null;
}
// We can't use `wrap` function as `f` is not a native function,
// so wrap it manually:
let f = function mozMatchesSelector(selectors) {
return this.mozMatchesSelector(selectors);
};
return getProxyForFunction(f, NativeFunctionWrapper(f));
},
// Bug 679054: History API doesn't work with Proxy objects. We have to pass
// regular JS objects on `pushState` and `replaceState` methods.
// In addition, the first argument has to come from the same compartment.
pushState: function (obj) {
// Ensure that we are on an object that expose History API
try {
obj.QueryInterface(Ci.nsIDOMHistory);
}
catch(e) {
return null;
}
let f = function fix() {
// Call native method with JSON objects
// (need to convert `arguments` to an array via `slice`)
return this.pushState.apply(this, JSON.parse(JSON.stringify(Array.slice(arguments))));
};
return getProxyForFunction(f, NativeFunctionWrapper(f));
},
replaceState: function (obj) {
// Ensure that we are on an object that expose History API
try {
obj.QueryInterface(Ci.nsIDOMHistory);
}
catch(e) {
return null;
}
let f = function fix() {
// Call native method with JSON objects
// (need to convert `arguments` to an array via `slice`)
return this.replaceState.apply(this, JSON.parse(JSON.stringify(Array.slice(arguments))));
};
return getProxyForFunction(f, NativeFunctionWrapper(f));
},
// Bug 769006: nsIDOMMutationObserver.observe fails with proxy as options
// attributes
observe: function observe(obj) {
// Ensure that we are on a DOMMutation object
try {
// nsIDOMMutationObserver starts with FF14
if ("nsIDOMMutationObserver" in Ci)
obj.QueryInterface(Ci.nsIDOMMutationObserver);
else
return null;
}
catch(e) {
return null;
}
return function nsIDOMMutationObserverObserveFix(target, options) {
// Gets native/unwrapped this
let self = this && typeof this.valueOf == "function" ?
this.valueOf(UNWRAP_ACCESS_KEY) : this;
// Unwrap the xraywrapper target out of JS proxy
let targetXray = unwrap(target);
// But do not wrap `options` through ContentScriptObjectWrapper
let result = wrap(self.observe(targetXray, options));
// Finally wrap result into JS proxies
return wrap(result);
};
}
};
/*
* Generate handler for proxy wrapper
*/
function handlerMaker(obj) {
// Overloaded attributes dictionary
let overload = {};
// Expando attributes dictionary (i.e. onclick, onfocus, on* ...)
let expando = {};
// Cache of methods overloaded to fix XrayWrapper bug
let methodFixes = {};
return {
// Fundamental traps
getPropertyDescriptor: function(name) {
return Object.getOwnPropertyDescriptor(obj, name);
},
defineProperty: function(name, desc) {
return Object.defineProperty(obj, name, desc);
},
getOwnPropertyNames: function () {
return Object.getOwnPropertyNames(obj);
},
delete: function(name) {
delete expando[name];
delete overload[name];
return delete obj[name];
},
// derived traps
has: function(name) {
if (name == "___proxy") return false;
if (isEventName(name)) {
// XrayWrappers throw exception when we try to access expando attributes
// even on "name in wrapper". So avoid doing it!
return name in expando;
}
return name in obj || name in overload || name == "__isWrappedProxy" ||
undefined !== this.get(null, name);
},
hasOwn: function(name) {
return Object.prototype.hasOwnProperty.call(obj, name);
},
get: function(receiver, name) {
if (name == "___proxy")
return undefined;
// Overload toString in order to avoid returning "[XrayWrapper [object HTMLElement]]"
// or "[object Function]" for function's Proxy
if (name == "toString") {
// Bug 714778: we should not pass obj.wrappedJSObject.toString
// in order to avoid sharing its proxy between two contents scripts.
// (not that `unwrappedObj` can be equal to `obj` when `obj` isn't
// an xraywrapper)
let unwrappedObj = XPCNativeWrapper.unwrap(obj);
return wrap(function () {
return unwrappedObj.toString.call(
this.valueOf(UNWRAP_ACCESS_KEY), arguments);
}, obj, name);
}
// Offer a way to retrieve XrayWrapper from a proxified node through `valueOf`
if (name == "valueOf")
return function (key) {
if (key === UNWRAP_ACCESS_KEY)
return obj;
return this;
};
// Return overloaded value if there is one.
// It allows to overload native methods like addEventListener that
// are not saved, even on the wrapper itself.
// (And avoid some methods like toSource from being returned here! [__proto__ test])
if (name in overload &&
overload[name] != Object.getPrototypeOf(overload)[name] &&
name != "__proto__") {
return overload[name];
}
// Catch exceptions thrown by XrayWrappers when we try to access on*
// attributes like onclick, onfocus, ...
if (isEventName(name)) {
//console.log("expando:"+obj+" - "+obj.nodeType);
return name in expando ? expando[name].original : undefined;
}
// Overload some XrayWrappers method in order to fix its bugs
if (name in methodFixes &&
methodFixes[name] != Object.getPrototypeOf(methodFixes)[name] &&
name != "__proto__")
return methodFixes[name];
if (Object.keys(xRayWrappersMethodsFixes).indexOf(name) !== -1) {
let fix = xRayWrappersMethodsFixes[name](obj);
if (fix)
return methodFixes[name] = fix;
}
let o = obj[name];
// XrayWrapper miss some attributes, try to catch these and return a value
if (!o) {
for each(let atttributeFixer in xRayWrappersMissFixes) {
let fix = atttributeFixer(obj, name);
if (fix)
return fix;
}
}
// Generic case
return wrap(o, obj, name);
},
set: function(receiver, name, val) {
if (isEventName(name)) {
//console.log("SET on* attribute : " + name + " / " + val + "/" + obj);
let shortName = name.replace(/^on/,"");
// Unregister previously set listener
if (expando[name]) {
obj.removeEventListener(shortName, expando[name], true);
delete expando[name];
}
// Only accept functions
if (typeof val != "function")
return false;
// Register a new listener
let original = val;
val = ContentScriptFunctionWrapper(val);
expando[name] = val;
val.original = original;
obj.addEventListener(name.replace(/^on/, ""), val, true);
return true;
}
obj[name] = val;
// Handle native method not overloaded on XrayWrappers:
// obj.addEventListener = val; -> obj.addEventlistener = native method
// And, XPCNativeWrapper bug where nested values appear to be wrapped:
// obj.customNestedAttribute = val -> obj.customNestedAttribute !== val
// obj.customNestedAttribute = "waive wrapper something"
// SEE BUG 658560: Fix identity problem with CrossOriginWrappers
// TODO: check that DOM can't be updated by the document itself and so overloaded value becomes wrong
// but I think such behavior is limited to primitive type
if ((typeof val == "function" || typeof val == "object") && name) {
overload[name] = val;
}
return true;
},
enumerate: function() {
var result = [];
for each (let name in Object.keys(obj)) {
result.push(name);
};
return result;
},
keys: function() {
return Object.keys(obj);
}
};
};
/*
* Wrap an object from the document to a proxy wrapper.
*/
function create(object) {
if ("wrappedJSObject" in object)
object = object.wrappedJSObject;
let xpcWrapper = XPCNativeWrapper(object);
// If we can't build an XPCNativeWrapper, it doesn't make sense to build
// a proxy. All proxy code is based on having such wrapper that store
// different JS attributes set.
// (we can't build XPCNativeWrapper when object is from the same
// principal/domain)
if (object === xpcWrapper) {
return object;
}
return getProxyForObject(xpcWrapper);
}