HTML and CSS Reference
In-Depth Information
15.7. Building an XML DTD
Now that we've emerged from the gory details of XML DTDs, let's see
how they work by creating a simple example. You can create a DTD with
any text editor and a clear idea of how you want to mark up your XML
documents. You'll need an XML parser and processing application to ac-
tually interpret and use your DTD, as well as a stylesheet to permit XML-
capable browsers to display your document.
15.7.1. An XML Address DTD
Let's create a simple XML DTD that defines a markup language for spe-
cifying documents containing names and addresses. We start with an
ad-
dress
element, which contains other elements that tag the address con-
tents. Our
address
element has a single attribute indicating whether it is
a work or a home address:
<!ELEMENT address (name, street+, city, state, zip?)>
<!ATTLIST address type (home|business) #REQUIRED>
Voilà
! The first declaration creates an element named
address
that con-
tains a name element, one or more street elements, a city and state ele-
ment, and an optional zip element. The
address
element has a single at-
tribute,
type
, which must be specified and can have a value of either
home
or
business
.
Let's define the
name
elements first:
<!ELEMENT name (first, middle?, last)>
<!ELEMENT first (#PCDATA)>
<!ELEMENT middle (#PCDATA)>
<!ELEMENT last (#PCDATA)>
