Unable to add custom elements using the document.execCommand - html

Question

I am trying to add a custom element into a editable div using document.execCommand detailed at https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand.
But when I try to add a custom polymer element using the execCommand, browser is unable to recognize the custom element even if it was already imported into scope.
var video-id='FnoL3d33U8o'//a youtube video Id
var html = '<p><div><custom-video-element width="454" height="280" video-id="'+videoUrl+'"></custom-video-element></div></p>';
document.execCommand('insertHTML', false, html);
But this doesn't help and the custom-video-element is not recognized by the browser. Please help if there is any alternate ways or if I am running after a mirage!

Answer 1

if you know what element you need to append, then you can use document.createElement.
There are multiple options how to achiev that, but In your case:
var p = document.createElement("p");
var div = document.createElement("div");
var custom = document.createElement("custom-video-element")
custom.setAttribute("video-id", videoUrl);
.. setting another attributes ..
div.appendChild(custom);
p.appendChild(div);
document.appendChild(p);
and that is it. This should work well.
Of course there might be better and easier solutions but in your case this isn't so bad.
if you create bigger html structure inside your JS, you will do something like:
var div = document.createElement("div");
var inner = "<div class="test"><div></div><p class="p"></p></div>;
div.innerHTML = inner;
div.querySelector(".p").appendChild(document.createElement("custom-video-element"));