in dart parse HTML string to DOM

You can create an element by parsing HTML text:

new Element.html("YOUR HTML STRING HERE");

see Dart: Up and Running CH03

EDIT
You may need to pass a NodeValidator to get the entire text rendered like:

NodeValidator nodeValidator = new NodeValidatorBuilder()
    ..allowTextElements();
    // ..allowHtml5()
    // ..allowElement('Button', attributes: ['ng-disabled']);

new Element.html("YOUR HTML STRING HERE", validator: nodeValidator);

If you run the application you get log messages like "element/attribute xxx removed from ..." if some of the text was not accepted by the NodeValidator.

Try html. It's 100% pure Dart, so you should be set.

You could also consider an XML parser for Dart like xml depending on the nature of your HTML.