How Can I Retrieve the URL from an IFRAME?

Retrieving Current URL from an IFRAME

When displaying content from external sources within an IFRAME, it can be desirable to access the URL of the displayed page. However, due to security limitations, this access is only possible under specific circumstances.

Cross-Origin Security Restrictions

For security reasons, retrieving the URL from an IFRAME within JavaScript is subject to cross-domain restrictions. Specifically, it is only possible to obtain the URL when the IFRAME and the referencing JavaScript are hosted on the same domain.

Accessing URL When Domains Match

In the scenario where the contents of the IFRAME and the referencing JavaScript are served from the same domain, obtaining the current URL is straightforward:

document.getElementById("iframe_id").contentWindow.location.href

Replace "iframe_id" with the identifier of the specific IFRAME.

Cross-Domain Limitations

However, when the domains of the IFRAME and parent page differ (cross-domain), cross-site scripting (XSS) security measures prevent direct URL retrieval. This is because allowing unrestricted access to URL information from an external domain poses a security risk.

Alternative Solutions

If the domains are mismatched and direct URL retrieval is not possible, consider alternative solutions:

• Child domain served from parent domain: Host the IFRAME content on a subdomain of the parent domain, allowing access to the URL.
• Ajax communication: Establish a direct connection between the parent page and child domain using the Ajax technique to retrieve the URL remotely.
• Cross-origin resource sharing (CORS): With CORS, the server can explicitly permit cross-origin requests, enabling access to the URL under certain conditions.

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