訪問變量從Greasemonkey的頁＆反之亦然

Question

我在test.js下面的代碼，其前右< /體運行>：

alert('stovetop'); 
alert(greasy); 

我在test.user下面的代碼.js文件：

(function() { 

    'use strict'; 
    var greasy = 'greasy variable'; 
    document.title = 'greasy title'; 

}()); 

「爐子」被驚動了，所以我知道JavaScript的工作頁面，document.title得到改變，所以我知道該腳本JavaScript的工作。然而，在網頁上我得到的錯誤：

Error: ReferenceError: greasy is not defined Source File: /test.js

如何從網頁訪問由Greasemonkey設置的變量，反之亦然？

Answer 1

• Greasemonkey腳本在一個單獨的操作範圍，並且還可以操作在沙箱中，這取決於@grant settings。

• 此外，該問題代碼將功能範圍內的greasy隔離（如gladoscc所述）。

• 最後，在默認情況下，test.js將觸發的Greasemonkey腳本執行之前，所以不會看到任何一組變量，反正。使用@run-at document-start來解決這個問題。

因此，鑑於這種test.js，</body>前右運行：

window.targetPages_GlobalVar = 'stovetop'; 

console.log ("On target page, local global: ", targetPages_GlobalVar); 
console.log ("On target page, script global: ", gmScripts_GlobalVar); 

然後下面的工作：

沒有沙箱：

// ==UserScript== 
// @name  _Greasemonkey and target page, variable interaction 
// @include  http://YOUR_SERVER.COM/YOUR_PATH/* 
// @include  http://jsbin.com/esikut/* 
// @run-at  document-start 
// @grant  none 
// ==/UserScript== 

//--- For @grant none, could also use window. instead of unsafeWindow. 
unsafeWindow.gmScripts_GlobalVar = 'greasy'; 

console.log ("In GM script, local global: ", unsafeWindow.targetPages_GlobalVar); 
console.log ("In GM script, script global: ", gmScripts_GlobalVar); 

window.addEventListener ("DOMContentLoaded", function() { 
    console.log ("In GM script, local global, after ready: ", unsafeWindow.targetPages_GlobalVar); 
}, false); 

隨着沙箱，無功能範圍，unsafeWindow：
== > 重要更新：Greasemonkey changed unsafeWindow handling with version 2.0, the next sample script will not work with GM 2.0 or later。另外兩個解決方案仍然有效。

// ==UserScript== 
// @name  _Greasemonkey and target page, variable interaction 
// @include  http://YOUR_SERVER.COM/YOUR_PATH/* 
// @include  http://jsbin.com/esikut/* 
// @run-at  document-start 
// @grant GM_addStyle 
// ==/UserScript== 
/*- The @grant directive is needed to work around a design change 
    introduced in GM 1.0. It restores the sandbox. 
*/ 

unsafeWindow.gmScripts_GlobalVar = 'greasy'; 

console.log ("In GM script, local global: ", unsafeWindow.targetPages_GlobalVar); 
console.log ("In GM script, script global: ", unsafeWindow.gmScripts_GlobalVar); 

window.addEventListener ("DOMContentLoaded", function() { 
    console.log ("In GM script, local global, after ready: ", unsafeWindow.targetPages_GlobalVar); 
}, false); 

隨着沙箱，無功能範圍，腳本注入：

// ==UserScript== 
// @name  _Greasemonkey and target page, variable interaction 
// @include  http://YOUR_SERVER.COM/YOUR_PATH/* 
// @include  http://jsbin.com/esikut/* 
// @run-at  document-start 
// @grant  GM_addStyle 
// ==/UserScript== 
/*- The @grant directive is needed to work around a design change 
    introduced in GM 1.0. It restores the sandbox. 
*/ 

function GM_main() { 
    window.gmScripts_GlobalVar = 'greasy'; 

    console.log ("In GM script, local global: ", window.targetPages_GlobalVar); 
    console.log ("In GM script, script global: ", window.gmScripts_GlobalVar); 

    window.addEventListener ("DOMContentLoaded", function() { 
     console.log ("In GM script, local global, after ready: ", window.targetPages_GlobalVar); 
    }, false); 
} 

addJS_Node (null, null, GM_main); 

function addJS_Node (text, s_URL, funcToRun, runOnLoad) { 
    var D         = document; 
    var scriptNode       = D.createElement ('script'); 
    if (runOnLoad) { 
     scriptNode.addEventListener ("load", runOnLoad, false); 
    } 
    scriptNode.type       = "text/javascript"; 
    if (text)  scriptNode.textContent = text; 
    if (s_URL)  scriptNode.src   = s_URL; 
    if (funcToRun) scriptNode.textContent = '(' + funcToRun.toString() + ')()'; 

    var targ = D.getElementsByTagName ('head')[0] || D.body || D.documentElement; 
    targ.appendChild (scriptNode); 
} 

---

注：

1. 您可以針對測試這些腳本3210。
2. 沒有沙箱，unsafeWindow和window是一樣的。

3. 這些腳本的製作控制檯上的相同的輸出：

   In GM script, local global: undefined 
   In GM script, script global: greasy 
   On target page, local global: stovetop 
   On target page, script global: greasy 
   In GM script, local global, after ready: stovetop 
   

4. 的腳本注入代碼將在各種除了Firefox瀏覽器的工作。 unsafeWindow目前僅適用於Firefox + Greasemonkey（或Scriptish）或Chrome + Tampermonkey。

Answer 2

您的變量greasy在匿名函數的範圍內定義。即使在你的腳本中，你也不能訪問greasy，除非它是你函數的一部分。例如：

(function(){ 
    var foo = 5; 
    alert(foo); 
}(); 
alert(foo); //ERROR, because foo is undefined outside of the function. 

這樣來做：

var foo = 5; 
(function(){ 
    alert(foo); 
}(); 
alert(foo); 

而且，你爲什麼把在一個匿名函數所有的代碼，然後執行它？