假设我正在使用以下网页:
<html> <body> <span id="click">click me</span> <script> var hello = function() { alert('hello'); } document.getElementById('click').addEventListener('click', function(e) { hello(); }); </script> </body> </html>
我的Greasemonkey脚本是:
// ==UserScript== // @name My Script // @include http://example.com/hello.html // @version 1 // @grant none // ==/UserScript== window.hello = function() { alert('goodbye'); }
在禁用Greasemonkey脚本的情况下,单击#click页面上的元素将显示“ hello”警报。启用脚本后,单击元素将显示“再见”警报。
#click
很简单。hello网页中的功能已被Greasemonkey脚本中的功能替换。
hello
现在,假设我要使用Greasemonkey API。当我将@grant值设置为’none’以外的有效值时(例如// @grant GM_setClipboard)[这会导致Greasemonkey将脚本作为“内容脚本”运行,而不是像“ none”一样在页面范围内运行],Greasemonkey脚本无法执行工作。
@grant
// @grant GM_setClipboard
window.hello 不再定位页面上的正确对象。
window.hello
更换window.hello用unsafeWindow.hello看起来像它的工作,而是下面的错误是在JS控制台抛出:
unsafeWindow.hello
错误:拒绝访问对象的权限
在@grant GM_setClipboard设置为目标并替换hello页面上的原始功能后,如何重写Greasemonkey脚本?
@grant GM_setClipboard
系统信息:
当您设置任何@grant其他值时,Greasemonkey会激活其沙箱,而Greasemonkey2.0将彻底改变unsafeWindow处理。
现在,为了在目标页面范围内创建或覆盖变量,您必须从技术菜单中正确选择。例如:
To Read:
一个简单的变量:
Target page sets: var foo = "bar";
GM script can read: unsafeWindow.foo //– “bar”
一个简单的对象:
Target page sets: var obj = {A: 1};
GM script can read: unsafeWindow.obj //– Object { A: 1 }
一个复杂的对象: 这并不总是可能的。
To Call:
Target page sets: function func () {console.log ('Hi');}
GM script can call: unsafeWindow.func() //– “Hi”
To Write/Set:
unsafeWindow.foo = "Apple";
var gmObject = {X: "123"};
unsafeWindow.obj = cloneInto (gmObject, unsafeWindow);
一个简单的功能:
function gmFunc () { console.log ("Lorem ipsum"); //-- Can use GM_ functions in here! :)
} unsafeWindow.func = exportFunction (gmFunc, unsafeWindow);
考虑以下HTML:
<button id="helloBtn">Say "Hello".</button>
而这个JavaScript:
var simpleGlobalVar = "A simple, global var in the page scope."; var globalObject = {Letter: "A", Number: 2}; function simpleFunction () { console.log ("The target page's simpleFunction was called."); } var sayHello = function() { console.log ('Hello.'); } document.getElementById ('helloBtn').addEventListener ('click', function () { sayHello (); } );
如果在该页面上安装并运行此Greasemonkey脚本:
// ==UserScript== // @name _Demonstrate accessing target-page variables with @grant values set // @include http://fiddle.jshell.net/sepwL7n6/*/show/ // @require http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js // @grant GM_addStyle // ==/UserScript== console.log ("*** Greasemonkey script start."); $("body").append ('<div id="gmArea">Added by Greasemonkey:<p></p></div>'); $("#gmArea > p:first").append ('<button id="gmShow">Access select target-page variables and functions</button>'); $("#gmArea > p:first").append ('<button id="gmChange">Change javascript things in the target-page scope.</button>'); $("#gmShow").click ( function () { //-- Access things from the target-page scope: console.log ("----------------"); console.log ("==> simpleGlobalVar is: ", unsafeWindow.simpleGlobalVar); console.log ("==> globalObject is: ", unsafeWindow.globalObject); console.log ("==> Calling target's simpleFunction():"); unsafeWindow.simpleFunction (); //-- WARNING! This next technique is not robust, but works in some cases. console.log ("==> Calling target's button's click()."); unsafeWindow.document.getElementById ('helloBtn').click (); } ); $("#gmChange").click ( function () { this.disabled = true; //-- Can only click once. unsafeWindow.simpleGlobalVar = "Simple var... Intercepted by GM!"; unsafeWindow.globalObject = cloneInto (gmObject, unsafeWindow); unsafeWindow.sayHello = exportFunction (sayHello, unsafeWindow); console.log ("==> Target page objects were changed."); } ); var gmMessageStr = "Function... Intercepted by GM, but also can use GM_ functions!"; function sayHello () { sayHello.K = (sayHello.K || 0) + 1; console.log (gmMessageStr); GM_addStyle ('body {background: ' + (sayHello.K % 2 ? "lime" : "white") + ';}'); } var gmObject = {message: "Object overridden by GM."};
打开控制台并按下按钮,您将看到GM脚本能够读取和更改页面的变量和功能。
笔记:
GM_