My website provides the dark mode button, so when button was click, I need to change the color theme of Dicourse Embeds to keep the same with my website.
But when I try to add class for body of embedded iframe, I found
iframe.contentDocument is always null, and if use
document.getElementById("discourse-embed-frame").contentWindow.document , the error as below:
I think there should be a way to config the embedded frame to allow cross-origin, but I still not found how to config after trying some config.
The other way maybe to use
document.getElementById("discourse-embed-frame").contentWindow.postMessage("darkMode"), but there needs to be an handler to handle the
darkMode message in script, I haven’t found where to add it.