Question

In a webapplication I came across, there is a javascript line in logout.jsp as:

parent.parent.renderProcessingTextOff();

On debugging the page with IE script debugger, it is breaking on above line with error as:

Object doesn't support this property or method

What is the meaning of this error?
How to solve it?

I am new to javascript, so please explain in simple terms.

Flow of logout is:

on click of logout button, a command is passed and intercepted in interceptor, which directs it to appropriate processor, which forwards the request to logout.jsp.

Its a spring application, if that information is of any help.

Thanks for reading!!

Answer 1

Are there frames or iframes on your page? Or object elements?

parent is a property of the window object (and the window. part of window.parent is assumed if you leave it out).

From MDN:

When a window is loaded in an <iframe>, <object>, or <frame>, its parent is the window with the element embedding the window.

So if from an iframe that is at least two levels down, the line parent.parent.renderProcessingTextOff(); says to call the renderProcessingTextOff() function defined by its grandparent.

Obviously if that line of code appeared where there wasn’t a grandparent with that function defined then you’ll get the error you quoted.