Components

Components 对象是 XPConnect 功能被映射到 JavaScript 上的对象。Components 对象的 native 实现位置在   nsIXPCComponents , 这个接口会被映射成JavaScript 作为使用 XPConnect 的最高层级的对象。

Components 的一些属性需要高级的全写，可能在 web 页面中不能正常工作。

 Components 对象包含下面的成员:

classes

array of classes by ContractID

classesByID

array of classes by CID

Constructor

constructor for constructor of components

Exception

constructor for XPConnect exceptions

ID

constructor for XPCOM nsIDs

interfaces

array of interfaces by interface name

interfacesByID

array of interfaces by IID

isSuccessCode

function to determine if a given result code is a success code

lastResult

result code of most recent XPConnect call

manager

the global XPCOM component manager

results

array of known result codes by name

returnCode

pending result for current call

stack

current JavaScript call stack

utils

provides access to several useful features

 

utils.atline

Provides access to the value of the atline property in the JavaScript environment.

utils.createObjectIn

Creates a new object in the scope of the specified object's compartment. May only be called from JavaScript code.

utils.evalInSandbox

Runs JavaScript code in a sandbox, usually used to run code with restricted privileges.

utils.forceGC

Forces a garbage collection cycle.

utils.getGlobalForObject 

Returns the global object with which a given object is associated (through its prototype chain at birth, for example).

utils.getWeakReference 

Gets a weak reference for the object passed in.

utils.import 

Loads a JavaScript module into the current script, without sharing a scope.

utils.lookupMethod

Looks up a native (i.e. declared in the interface) method or property of an XPCOM object. Serves the same purpose as XPCNativeWrapper.

utils.makeObjectPropsNormal

Ensures that all functions come from the specified object's scope, and aren't cross-compartment wrappers. May only be called from JavaScript code.

utils.methodjit 已废弃 Gecko 24.0

Provides access to the value of the methodjit property in the JavaScript environment.

utils.methodjit_always 已废弃 Gecko 24.0

Provides access to the value of the methodjit_always property in the JavaScript environment.

utils.relimit

Provides access to the value of the relimit property in the JavaScript environment.

utils.reportError

Reports a JavaScript Error object to the Error Console.

utils.schedulePreciseGC

Requests that garbage collection occur sometime in the future when no JavaScript code is running; accepts a callback function to receive notification once collection is complete.

utils.setGCZeal()

Sets the GC zeal level for the context.

utils.strict

Provides access to the value of the strict property in the JavaScript environment.

utils.werror

Provides access to the value of the werror property in the JavaScript environment.

utils.Sandbox

Creates sandbox objects for use with evalInSandbox.

utils.xml

Provides access to the value of the xml property in the JavaScript environment.