After hours of GWT and Errai code debugging I've found what I think it is a Bug in the code.

I was trying to use ListWidget to create and paint <TR> like items... and trying to find out what fails in this kind of code, I arrived to TemplateUtil class where in the method:

  private static Element firstNonMetaElement(final Element parserDiv) {
    Element displayable = parserDiv.getFirstChildElement();
    while (displayable != null && displayable.getTagName().equalsIgnoreCase("meta")) {
      displayable = displayable.getNextSiblingElement();
    }


    return displayable;
  }

We are using the Element objects "getFirstChildElement" method which has this code:

  /**
  * The first child of element this element. If there is no such element, this
  * returns null.
  */
  public final Element getFirstChildElement() {
    return DOMImpl.impl.getFirstChildElement(this);
  }

And finally uses this native method:

  public native Element getFirstChildElement(Element elem) /*-{
    var child = elem.firstChild;
    while (child && child.nodeType != 1)
      child = child.nextSibling;
    return child;
  }-*/;

What I see in this method is that the code is using firstChild which is not a Element type object... It is a Text Object.

So if what I think it's true child.nodeType will never return a 1... cause never is going to be a Element type object. It will retun a 3 and will keep looking for "siblings" till child is null.

This way it is not returning the firstChildElement to the TemplateUtil making it fail.

This is a resume of what I found, I'd love someone to confirm my theory or tell me what did I undestand wrong.