Question

I started learning XML yesterday but I cant get around the concept of DTD.

My thinking is that, this will cause an error since my picture tag contains a whitespace character and I explicitly mention in my DTD that this should contain only EMPTY element.

As per my understanding, empty element does not contain any character at all. Whitespace is a character I think.

But I am not sure why my eclipse editor is not displaying an error related to this?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE person [
<!ELEMENT person (picture) >
<!ELEMENT picture  EMPTY >
]>
<person>

 <picture></picture>

</person>

Any thoughts?

Answer 1

The XML you’ve posted doesn’t actually include any whitespace which is why it validates just fine. If you had something like this:

<person>
     <picture> </picture>
</person>

you would have whitespace. An empty element can be written as either <picture/> or <picture></picture>. They are equivalent.