访问从 Greasemonkey 到 Page & 的变量反之亦然 [英] Accessing Variables from Greasemonkey to Page & vice versa

问题描述

我在 test.js 中有以下代码，它在 </body> 之前运行:

I have the following code in test.js which is run right before </body>:

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

我在 test.user.js 中有以下代码:

I have the following code in test.user.js:

(function () {

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

}());

'stovetop' 收到警报，所以我知道页面 javascript 有效，而 document.title 得到更改，所以我知道脚本 javascript 有效.但是，在网页上我收到错误:

'stovetop' gets alerted so I know the page javascript works, and document.title gets changes so I know that the script javascript works. However, on the webpage I get the error:

错误:ReferenceError:greasy 未定义源文件:/test.js

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

如何从网页访问由 Greasemonkey 设置的变量，反之亦然?

How from the webpage do I access the variable set by Greasemonkey and how about vice versa?

推荐答案

• Greasemonkey 脚本在单独的范围内运行，也可能在沙箱中运行，具体取决于 <代码>@grant 设置.

  此外，问题代码将greasy隔离在一个函数范围内(如gladoscc所说).

  Additionally, the question code isolates greasy in a function scope (as gladoscc said).

  最后，默认情况下，test.js 将在 Greasemonkey 脚本执行之前触发，因此无论如何它都不会看到任何设置的变量.使用 @run-at document-start 来解决

  Finally, by default, test.js will fire before the Greasemonkey script does, so it won't see any set variables, anyway. Use @run-at document-start to address that.

  
  所以，给定这个 test.js，在 之前运行:

  
  So, given this test.js, run right before </body>:

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

  然后以下将起作用:

  无沙箱:

  // ==UserScript==
  // @name        _Greasemonkey and target page, variable interaction
  // @include     http://YOUR_SERVER.COM/YOUR_PATH/*
  // @include     http://output.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);
  

  
  带沙箱，没有函数作用域，unsafeWindow:
  ==>重要更新: Greasemonkey 在 2.0 版中更改了 unsafeWindow 处理，下一个示例脚本不适用于 GM 2.0 或更高版本.其他两种解决方案仍然有效.

  
  With sandbox, no function scope, unsafeWindow:
  ==> Important update: Greasemonkey changed unsafeWindow handling with version 2.0, the next sample script will not work with GM 2.0 or later. The other two solutions still work.

  // ==UserScript==
  // @name        _Greasemonkey and target page, variable interaction
  // @include     http://YOUR_SERVER.COM/YOUR_PATH/*
  // @include     http://output.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);
  

  
  使用沙箱，没有函数作用域，脚本注入:

  // ==UserScript==
  // @name        _Greasemonkey and target page, variable interaction
  // @include     http://YOUR_SERVER.COM/YOUR_PATH/*
  // @include     http://output.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);
  }
  

  <小时>

  注意事项:

  ---

  Notes:

  1. 您可以针对此页面(output.jsbin.com/esikut/1).
  2. 没有沙箱，unsafeWindow 和 window 是一样的.

  3. 所有这些脚本在控制台上产生相同的输出:

  1. You can test these script against this page (output.jsbin.com/esikut/1).
  2. With no sandbox, unsafeWindow and window are the same.

  3. All of these scripts produce the same output on the console:

  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
  

• 脚本注入代码可以在 Firefox 之外的各种浏览器中运行.unsafeWindow 目前仅适用于 Firefox+Greasemonkey(或 Scriptish)或 Chrome+Tampermonkey.

• The Script Injection code will work in a variety of browsers besides Firefox. unsafeWindow currently only works in Firefox+Greasemonkey(or Scriptish) or Chrome+Tampermonkey.

  这篇关于访问从 Greasemonkey 到 Page &amp; 的变量反之亦然的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！