在Firefox中与Web内容（页面对象）共享插件对象（内容脚本）

Question

I spent days trying to share one of my Firefox for Android extension objects with the webpages I also open from my extension (declared as resources). The thing is I have read a lot about the last year's changes about unsafewindow, so I tryed a very small example with the new functions but didn't work. I copied the examples and I also tryed my owns, but there is no way to copy existing objects with functionality. See, I have a VERY big object to clone in the content window, but I decided to test with a small one:

//From addon
var dog = {
    name: 'Spike',
    woof: function(){alert('woof woof!')}
};

And after that I tryed to copy this object into the active window:

//From addon
var contentWindow = window.BrowserApp.selectedBrowser.contentWindow;
contentWindow.dog = Components.utils.cloneInto(
    dog, 
    contentWindow, 
    {cloneFunctions: true}
);

And after that, I tryed to check what was really copied:

alert(contentWindow.dog); //Shows: [object Object]
alert(contentWindow.dog.name); //Shows: Spike
alert(contentWindow.dog.woof); //Shows: undefined

So, I can clone the objects but no the functions, even when I declared "cloneFunctions: true".

I also tryed to create an empty object and then assign the functions (a lot of work thinking in my so big original object), and didn't work:

function greetme(user) {
    return "cheers " + user;
}
var foo = Components.utils.createObjectIn(contentWindow,{defineAs: "foo"});
Components.utils.exportFunction(greetme, foo, {defineAs: "greetme"}); 
//foo is not an object in current window

So... Any idea is welcome, I really don't know what to do because theory and given examples doesn't work anymore.

Thanks (A LOT) in advance!!

https://blog.mozilla.org/addons/2014/04/10/changes-to-unsafewindow-for-the-add-on-sdk/

Answer 1

Your code is more or less correct already, however, you're running into trouble with XRay wrappers. And, in order for the content window (website) to actually see you dog , you need to waive the XRay wrapper on the content window as well.

I tested the following with the current Firefox for Android Nightly (sorry, my release Firefox is not configured for remote debugging).

Ran this in the Main Process (using the WebIDE):

var dog = {
  name: 'Spike',
  woof: function () {
    alert(contentWindow.document.title + "\n" + this.name + ': woof woof!');
  }
};

var contentWindow = BrowserApp.selectedBrowser.contentWindow;

// Need to unwrap this, so that we can actually set properties on the
// object itself and not just the wrapper. Aka. make "dog" visible to
// the actual script.
var unsafeWindow = Components.utils.waiveXrays(contentWindow);

// Define Window.dog (on the unsafe window, so that the website code
// can actually see it).
unsafeWindow.dog = Components.utils.cloneInto(dog, contentWindow, {
  cloneFunctions: true
});

Then I switched over to the actual tab and tested:

dog.woof();

And it worked.