I was developing a GreaseMonkey script which used window.showModalDialog.
But before finishing it, I have discovered that Firefox 29 warns:
Use of window.showModalDialog() is deprecated. Use window.open() instead. For more help https://developer.mozilla.org/en-US/docs/Web/API/Window.open
But the problem is that window.open needs UniversalBrowserWrite privilege in order to open a modal window using window.open.
Then, why is window.showModalDialog deprecated? Is there any API which doesn't require privileges?
Note: I don't want a fake modal dialog (like jQuery's one), I need a real modal which pauses JavaScript execution.