This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
controllers property of the
Window interface returns the XUL controllers of the chrome window.
controllers = window.controllers
XUL-specific. Not part of specification.
By default, a window's controller contains the code that supports the global window commands.
Chrome code can add controllers (to be used in conjunction with the
goUpdateCommand functions in globalOverlay.js).
However, the added controllers must be explicitly removed when the window is unloaded, as this is not done automatically.
Each missing removal can causebug 415775:
ASSERTION: XPConnect is being called on a scope without a 'Components' property!