Question

I am fairly new to JavaScript and I am trying to get value of a variable from an embedded iframe. I have resorted to basic testing to make sure I am getting the method right…

I have tried the common suggestions and everything returns ‘undefined’. I want to use the variable in an onclick event.

In the iframe content I have stripped everything and just for testing have this:

<script>
var test = "test";
</script>

in the parent window I have done this:

<iframe src="iframe.html" id="iframe" width="200" height="100"></iframe>

<script>
var myVar = window.frames[0].window.test;
</script>
<a href="#" onclick='alert(myVar)' id="link">Click</a>

I have tried the options suggested here: grab global variable from an embedded iframe

Everything I do returns undefined… am I doing something fundamentally wrong?

Thanks in advance..

Answer 1

You are already executing the script when the <iframe> is still loading, so it’s test is undefined. Either wait for the iframe’s load event, or just get the variable when clicking:

<iframe src="iframe.html" id="iframe" width="200" height="100"></iframe>

<script>
var myFrame = window.frames[0].window;
</script>
<a href="#" onclick='alert(myFrame.test)' id="link">Click</a>