Dart, why does using innerHtml to set shadow root content work but appendHtml doesn't?

问题

I have made this Gist to show the issue but essentially I have found that using shadowRoot.innerHtml = '...' works but using shadowRoot.appendHtml('...') doesn't work, it causes the console warning Removing disallowed element <STYLE> which I can't explain. Anyone know if this is simple the way it is meant to be or is it specific to Dart?

回答1:

Removing disallowed element indicates that you need a NodeValidator.

shadowRoot.append(
    new document.body.createFragment('....'), 
    validator: new NodeValidationBuilder().allow(...);

来源：https://stackoverflow.com/questions/24000995/dart-why-does-using-innerhtml-to-set-shadow-root-content-work-but-appendhtml-do