How Can You Detect Changes to an iFrame\'s Source When You Cannot Control Its Content?

Detecting Source Changes in iFrames on Parent Page

When working with iFrames that have content you cannot control, detecting changes to their source becomes challenging. This article explores ways to address this issue.

Leveraging the onLoad Event

One solution involves utilizing the onLoad event. By assigning an event listener to this event, you can execute a custom function whenever the iFrame's source changes. An example of this is shown below:

<code class="html"><iframe src="http://www.google.com/" onLoad="alert('Test');"></iframe></code>

This code would display an alert message every time the iFrame's location changes. However, it's worth noting that this method may not be fully compatible with older browsers like IE5 and early Opera versions.

Accessing Location with contentWindow.location

If the iFrame is displaying a page within the same domain as the parent, accessing its location becomes possible using contentWindow.location. Here's an example:

<code class="html"><iframe src="/test.html" onLoad="alert(this.contentWindow.location);"></iframe></code>

This code would display an alert with the location of the page within the iFrame. Remember to consider cross-domain restrictions and browser compatibility when implementing this method.

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