8

I'm working in a framed environment, and trying to tell if the frame on which some javascript code executes is the top frame (the one that contains the rest).

Up until now I was trying to check it with

window.parent != null

but it always returns false, like in this simple example.

<html>
<head>
  <script>
    alert(parent == null);
  </script>
</head>

<body>
  <h1>OH YEAH!</h1>
</body>
</html>

Is there a way to do this? I doesn't have to be portable, right now I'm looking for the IE6 solution.

zb226
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Tom
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3 Answers3

8

I found this pdf to be very useful: http://seclab.stanford.edu/websec/framebusting/framebust.pdf

In short, if this is too long to read, this is what they ultimately propose : 

<style>
  html { display :none; }
</style>
<script>
if(self==top){
  document.documentElement.style.display = 'block';
}else{
top.location=self.location;
}
</script>

You will find many other means to do this in this pdf and each means' pro and cons. Obviously, on browsers without JavaScript, this solution could be painful ;)

Wladimir Palant
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tomdemuyt
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7
self === top

should return true if executed in the topmost frameset, false otherwise.

NickFitz
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1

You can check if top.frames.length == 0.

Daniel Egeberg
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