Why doesn't IXMLNode.IsTextElement return True for CDATA elements?

问题

We're using Delphi 2007 and the oxmldom Open XML provider.

A normal situations input file looks similar to this:

<root>
  <child>Some Text</child>
</root>

Now we have to process an input file that uses the CDATA node type:

<root>
  <child><![CDATA[Some special Text]]></child>
</root>

Node.IsTextElement suddenly returns False, but Node.Text still works as expected.

I know that IXMLNode.IsTextElement is just a convenience method, but I find this behavior rather odd.

As a workaround we're now using this custom method:

class function TXmlUtils.IsTextOrCDataElement(ANode: IXMLNode): Boolean;
begin
  Result := False;
  if ANode.ChildNodes.Count = 0 then begin
    if ANode.NodeType in [ntText, ntCData] then begin
      Result := True;
    end;
  end else
  if ANode.ChildNodes.Count = 1 then begin
    if ANode.ChildNodes.First.NodeType in [ntText, ntCData] then begin
      Result := True;
    end;
  end;
end;

My question is: Why does IsTextElement not work with CDATA nodes and is there an easier workaround?

回答1:

It doesn't return true for Cdata nodes because that's just not the way it was written. It's unfortunate because consumers of XML data generally shouldn't be concerned with how text is represented in the serialized data. Your alternative is fine.

回答2:

As Ritsaert Hornstra wrote in comment CDATA is not TEXT node of DOM tree. It's CDATA node.

Text property is something different. E.g. when current node is an attribute, Text will probably return value of this attribute.

If you want to check if current node is CDATA node or TEXT node, simply use Delphi is operator. There is also something like nodeType property which you are using anyway :-)

回答3:

If you want to check if current node is CDATA node or TEXT node, simply use Delphi is operator. There is also something like nodeType property which you are using anyway :-)

? XML CDATA read

来源：https://stackoverflow.com/questions/8416986/why-doesnt-ixmlnode-istextelement-return-true-for-cdata-elements

标签

xml

Delphi

delphi-2007