在Dart中创建聚合物元素的实例，它不是HtmlElement

Question

I have a PolymerElement called NewEntryElement, and I want it to be created and added if a Button is clicked.

new-Entry.html

<polymer-element name="new-Entry" attributes="metaData">
  <!-- a table here -->
</polymer-element>

new-Entry.dart

@CustomTag('new-entry')
class NewEntryElement extends PolymerElement {
  @published List<Map> metaData;

  factory NewEntryElement() => document.createElement("new-entry");

  NewEntryElement.created() : super.created() {
    polymerCreated();
  }
}

Calling the factory in my button function does not work, since a HtmlElement is created and it can't be cast to NewEntryElement. So i also tried to call this in my Button function:

var newEntry = new Element.tag('new-entry');
(newEntry as NewEntryElement).metaData = this.metaData;

There is the same Problem... So I need a way to get an Instance of my PolymerElement so i can assign the attribute metaData to the Element.

Btw: this is the Exception:

Exception: Uncaught Error: type 'HtmlElement' is not a subtype of type 'NewEntryElement' in type cast.

Answer 1

This normally works without problems. There seems to be something wrong with your polymer initialization code or element imports.

You have named your element "new-Entry" in HTML but use "new-entry" in code (upper-/lower-case e ) this is probably what causes the problem.