A Final Word

In this column we continued our series on Web services. This is the third in a miniseries about XML loading and manipulating of the DOMDocument object. We focused in this column on integrating document type definitions (DTDs) in XML file loading. We showed you the two functions of DTDs: validate the XML file structure and defining real values for entity references. We explained the differences between loading XML in the browser and with JavaScript. We went into the specific details regarding the reflection of entity references on the DOMDocument tree representation. We also walked you through two examples for entity reference insertion.

In this column you have learned:

• How to assemble and call DTDs
• How to define an XML file structure
• How to reference and specify entities
• How to load DTDs with a browser
• How to load DTDs with JavaScript
• How to add entity references on the fly

You can find a listing of our XML, XSL, and DTD files on Page 8, or you can download them directly from this zipped file.