Dynamically add key binding in polymer

[sudipta1411]

I am using IronA11yKeysBehavior to implement keyboard shortcut handling in my project. I have a polymer element <my-element></my-element> in which I have defined the keyBindings property as follows

keyBindings : {
    'shift+a' : '_onKeyPreseed'
}

The element is working as expected. But I want to dynamically assign keyboard shortcuts (so that a user can change the shortcuts as per her requirements). Say I want to change the shortcut from shift+a to alt+a. How to do this?

I have changed the 'keyBindings' property, but that is not working, still _onKeyPreseed is called when shift+a is pressed, not when alt+ais pressed.