https://nalar.dev/tags/coop/ Recent content in COOP on Nalar Hugo en-us Wed, 16 Sep 2026 00:00:00 +0700 https://nalar.dev/cross-origin-opener-policy-separates-window-relationships-at-the-browsing-context-boundary/ Wed, 16 Sep 2026 00:00:00 +0700 https://nalar.dev/cross-origin-opener-policy-separates-window-relationships-at-the-browsing-context-boundary/ <h1 id="cross-origin-opener-policy-separates-window-relationships-at-the-browsing-context-boundary">Cross-Origin Opener Policy Separates Window Relationships at the Browsing Context Boundary</h1> <p>A browser can prevent a cross-origin popup from reading most properties of its opener and still preserve a live relationship between the two windows. The same-origin policy restricts direct access to a foreign document, but a cross-origin <code>WindowProxy</code> can remain reachable, expose a limited interface, participate in navigation relationships, and carry observable state such as whether the referenced window is closed.</p>