问题描述

我有基于内容脚本的 Chrome 扩展程序.我通过内容脚本中的弹出窗口启动登录过程.

I have content script based Chrome extension. I initiate the sign in process through a popup window in the content script.

我使用下面的代码打开一个弹出窗口，然后等待它关闭.

I open a popup window using the below code and then wait till its closed.

但是，我从 window.open 方法中得到一个未定义".有人知道为什么会这样吗?

However, I get an 'undefined' from window.open method. Does anybody know why this happens?

loginwin 在下面的代码中是 undefined，尽管弹出窗口打开时使用指定的 login_url 很好.下面的代码是从我的内容脚本中调用的.

loginwin is undefined in below code although the popup window opens up fine with the specified login_url. The code below is called from my content script.

var loginWin = window.open(login_url, 'LoginWindow', "width=655,height=490");
console.log(loginWin);
// Check every 100 ms if the popup is closed.
var finishedInterval = setInterval(function() {
    console.log('checking if loginWin closed');
    if (loginWin.closed) {
        clearInterval(finishedInterval);
        console.log('popup is now closed');
        Backbone.history.navigate('index', true);
    }
}, 1000);

推荐答案

注意:此答案已过时.Chrome 扩展中的 window.open() 总是返回 null (当弹出窗口被阻止时)或 window 对象.以下信息仅适用于非常旧的 (2012) 版本的 Chrome.

Note: This answer is obsolete. window.open() in a Chrome extension always returns either null (when the popup is blocked) or a window object. The information below only applies to very old (2012) versions of Chrome.

<小时>

内容脚本无法访问页面的全局 window 对象.对于内容脚本，以下内容适用:

Content scripts do not have any access to a page's global window object. For content scripts, the following applies:

• window 变量不引用页面的全局对象.相反，它指的是一个新的上下文，一个页面上的层".页面的 DOM 是完全可访问的.^{#execution-environment}

• 对框架内容的访问受到页面同源策略的限制;您的扩展程序的权限不会放宽政策.
• frames[0] 和 frames['frameName']，(通常指帧的包含全局 window 对象)是 <强>未定义.
• var iframe = document.getElementById('frameName');
  • iframe.contentDocument 返回包含框架的 document 对象，因为内容脚本可以访问页面的 DOM.当应用同源策略时，此属性为 null.
  • iframe.contentDocument.defaultView(指与文档关联的window对象)是undefined.
  • iframe.contentWindow 是未定义.
  • Access to the contents of a frame is restricted by the Same origin policy of the page; the permissions of your extension does not relax the policy.
  • frames[0] and frames['frameName'], (normally referring to the the frame's containing global window object) is undefined.
  • var iframe = document.getElementById('frameName');
    • iframe.contentDocument returns a document object of the containing frame, because content scripts have access to the DOM of a page. This property is null when the Same origin policy applies.
    • iframe.contentDocument.defaultView (refers to the window object associated with the document) is undefined.
    • iframe.contentWindow is undefined.

    如您所见，window.open() 不返回 Window 实例(window.opener 也不返回，等等).

    As you can see, window.open() does not return a Window instance (neither does window.opener, and so forth).

    • 在页面中注入代码，使其在页面上下文中运行.注意:仅当您正在操作的页面可以信任时才使用此方法.要在注入脚本和内容脚本之间进行通信，您可以使用:

    • Inject the code in the page, so that it runs in the context of the page. Note: Only use this method if the page you're operating on can be trusted. To communicate between the injected script and the content script, you could use:

    var login_url = 'http://example.com/';
    var event_name = 'robwuniq' + Math.random().toString(16); // Unique name
    document.addEventListener(event_name, function localName() {
        document.removeEventListener(event_name, localName); // Clean-up
        // Your logic:
        Backbone.history.navigate('index', true);
    });
    // Method 2b: Inject code which runs in the context of the page
    var actualCode = '(' + function(login_url, event_name) {
        var loginWin = window.open(login_url, 'LoginWindow', "width=655,height=490");
        console.log(loginWin);
        // Check every 100 ms if the popup is closed.
        var finishedInterval = setInterval(function() {
            console.log('checking if loginWin closed');
            if (loginWin.closed) {
                clearInterval(finishedInterval);
                console.log('popup is now closed');
                // Notify content script
                var event = document.createEvent('Events');
                event.initEvent(event_name, false, false);
                document.dispatchEvent(event);
            }
        }, 1000);
    } + ')(' + JSON.stringify(login_url+'') + ', "' + event_name + '")';
    var script = document.createElement('script');
    script.textContent = actualCode;
    (document.head||document.documentElement).appendChild(script);
    script.parentNode.removeChild(script);
    

  • 使用 window.open() 从后台页面启动窗口.这将返回一个 window 对象，该对象具有可靠的 closed 属性.有关通信流程的更多详细信息，请参阅下一个要点.

  • Launch the window from the background page using window.open(). This returns a window object which has a reliable closed property. See the next bullet point for more details on the communication flow.

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