iframe postmessage not working

Any idea how to use IFRAME in windows application? the sending browsing context. However, when I do so, I get an error of the form: Note that this only occurs from iframe to parent, not the other way around. Adding a title to the tag gives users more context for what is the iframe is about. In comparison to real life, this is a situation when you would like to send a postcard to your child, before he or she mounted post box in front of his or her new home. As with any asynchronously-dispatched script (timeouts, user-generated events), it is @RobertSussland well, I went back to my code today to try and strip it down to the minimum needed to demonstrate the error and well, I can't reproduce it today. If you simply change your code to vfWindow.postMessage ('Preview Cleared','*'); it should work. Avoid using the OnLoad event. But did you think what is wrong with that approach from basic example above? Allows the resource to open new popups or tabs. Because we look how we find the child or parent window in JavaScript code is tightly connected to way how this window was created. It might look something like this: This, of course, fails (on the first line) with an error message similar to: "Unsafe JavaScript attempt to access frame with URL http://domain.com/ from frame with URL file:///index.html. Easy peasy lemon squeezy! It may not look like a postMessage related error, but at the time it was definitely being caused after script in my iframe called parent.postMessage() to send a message back to the parent lightning app component. Find centralized, trusted content and collaborate around the technologies you use most. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, HTML 5 PostMessage / Detect iFrame Failed To Load. The best answers are voted up and rise to the top, Not the answer you're looking for? Lightning Components: Why Geolocation fields in SOQL lead to an Internal Server Error? the structured clone Send the message from the parent element: Note: Keep in mind that you can end up in some tricky situations when you need to debug something as messages are fire-and-forget (i.e., there is no real error handling). and sends a message back on the MessageChannel using postMessage(). When should I use in JavaScript Windows postMessage? Chris Coyier snippet is a really a good one, the white flash is not there any more. any event listeners for message events. rev2023.4.21.43403. A minor scale definition: am I missing something? I often leave it out because I don't care who knows the sizing of the document body. When a gnoll vampire assumes its hyena form, do its HP change? the received message. control) can listen in. However when I try to load the second video it will not load in the iframe, it loads in a new tab. * In the popup's scripts, running on http://example.com: Note: The loading="lazy" attribute also works with the img tag, in case you didnt know that already. Can iframes affect the loading speed of my website? MessageEvent on it with targetWindow.postMessage(). Another thing to keep in mind is that when your iframe includes non-readable content (like, for instance, a video game built with JavaScript), you will have to hide its contents from screen reader users using the aria-hidden attribute. Also I have been checking the src of frame directly on element in console which shows same origin of lightning.force. Addressing accessibility concerns that are caused by iframes would be a valuable addition. To javascript, iFrames are typically black boxes. How do I stop the Flickering on Mode 13h? They have many legitimate uses cases. TYPE is like an endpoint in API, it tells CHILD or PARENT window what action you want to trigger and what to do with received data: sendMessage method, which takes as argument the window object (can be CHILD or PARENT window reference object), and PAYLOAD, so data to be sent. I could put a relay with some timeout logic that we are in control of in between a.com and b.com (a.com posts to a.com/relay, which in turn posts to b.com/proxy, etc. targetOrigin sigh. I also noticed that when using speed testing sites such as Google insights and GTMetrics, the browser is seeing and loading the content within the iframe even though I am using the lazy loading tag in the iframe?