XML by Example

Obviously, if the URIs in the catalog point to local copies of the DTD, the

XML processor saves some downloads.

Listing 3.4 is an example of a catalog file.

Listing 3.4: A Catalog File

<XMLCatalog>

<Base HRef=”http://catwoman.pineapplesoft.com/dtd/”/>

<Map PublicId=”-//Pineapplesoft//Address Book//EN”

HRef=”address-book.dtd”/>

<Map PublicId=”-//Pineapplesoft//Article//EN”

HRef=”article.dtd”/>

<Map PublicId=”-//Pineapplesoft//Simple Order//EN”

HRef=”order.dtd”/>

<Extend Href=”http://www.w3.org/xcatalog/mastercat.xml”/>

</XMLCatalog>

Finally, note that a document can have both an internal and an external

subset as in

<!DOCTYPE address SYSTEM “address-content.dtd” ...