javascript - 从 Firefox 扩展获取变量

Question

我正在做一些非常简单的事情......我无法弄清楚。我创建了一个扩展，它所做的只是获取一个变量。我希望能够从我的网页访问该变量。有什么想法吗？

我为什么要这样做的一点背景。我需要有 chrome 访问权限才能获得这个变量，这就是我首先制作这个扩展的原因。

Answer 1

您可能想查看此链接：Interaction between privileged and non-privileged pages for some code-samples on send data from chrome (priveleged) to unprivileged document (webpage).

在扩展中：

var myExtension =
{
  myListener: function(evt)
  {
    alert("Received from web page: " + 
           evt.target.getAttribute("attribute1") + "/" +
           evt.target.getAttribute("attribute2"));

/* the extension answers the page*/
    evt.target.setAttribute("attribute3", "The extension");

    var doc = evt.target.ownerDocument;

    var AnswerEvt = doc.createElement("MyExtensionAnswer");
    AnswerEvt.setAttribute("Part1", "answers this.");

    doc.documentElement.appendChild(AnswerEvt);

    var event = doc.createEvent("HTMLEvents");
    event.initEvent("MyAnswerEvent", true, false);
    AnswerEvt.dispatchEvent(event);
  }
}

document.addEventListener("MyExtensionEvent", function(e) { myExtension.myListener(e); }, false, true);
// The last value is a Mozilla-specific value to indicate untrusted content is allowed to trigger the event.

在网页中：

document.addEventListener("MyAnswerEvent",function(e) { ExtensionAnswer(e); },false);

var element;

function CallExtension()
{
  var element = document.createElement("MyExtensionDataElement");
  element.setAttribute("attribute1", "foobar");
  element.setAttribute("attribute2", "hello world");
  document.documentElement.appendChild(element);
  var evt = document.createEvent("Events");
  evt.initEvent("MyExtensionEvent", true, false);
  element.dispatchEvent(evt);
}

function ExtensionAnswer(EvtAnswer)
{
  alert(element.getAttribute("attribute3") + " " +
        EvtAnswer.target.getAttribute("Part1"));
}

希望这可以帮助。