igl*_*vzx 5 javascript firefox greasemonkey
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');
}
禁用Greasemonkey脚本后,单击#click页面上的元素将显示"hello"警报.启用脚本后,单击该元素将显示"再见"警报.
很简单.在hello从网页的功能正在由Greasemonkey的脚本功能所取代.
现在让我们说我想使用Greasemonkey API.当我将@grant值设置为除'none'之外的有效值(例如// @grant GM_setClipboard)[导致Greasemonkey将脚本作为"内容脚本"运行时,而不是像'none'那样在页面的范围内运行),Greasemonkey脚本无法工作.
window.hello 不再定位页面上的正确对象.
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:
错误:拒绝访问对象的权限
如何在@grant GM_setClipboard设置目标并替换hello页面上的原始函数时重写Greasemonkey脚本？
系统信息:
Bro*_*ams 17
当您设置@grant非none以外的值时,Greasemonkey会激活其沙箱,Greasemonkey 2.0会彻底更改unsafeWindow处理.
现在,为了在目标页面范围中创建或覆盖变量,您必须从技术菜单中正确选择.例如:
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: 这并不总是可行的.
一个简单的功能:
Target page sets: function func () {console.log ('Hi');}
GM script can call: unsafeWindow.func() //-- "Hi"
复杂的功能: 这并不总是可行的.
一个简单的变量:
unsafeWindow.foo = "Apple";
一个简单的对象:
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);
考虑这个HTML:
<button id="helloBtn">Say "Hello".</button>
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 ();
} );
你可以在这个jsFiddle页面看到它.
如果您针对该页面安装并运行此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_函数.