The Pros of Indesign & XML

Like its cousin HTML, XML defines document structure.

If you've spent time writing or perusing HTML code, you've seen text enclosed in formatting tags that designate how Web page content fits into the structure of an HTML page. XML, or eXtensible Markup Language, shares its roots with HTML as a descendant of SGML, or Standard Generalized Markup Language, originally designed for data sharing among early computers with incompatible proprietary systems.

XML Vs. HTML

XML and HTML may be related, but their focus and functionality differ. Whereas HTML creates the structure to display a page, XML defines a data structure and doesn't address the task of describing its appearance. Whereas HTML offers prefabricated codes for basic units of Web page content, XML gives you the rules and the linguistic structures you can use to create a language that defines your unique data. Perhaps most significantly, XML and HTML differ in their tolerance for bad code. HTML pages display despite coding errors, even egregious ones. By contrast, one mistyped tag makes an XML document fail, taking the application that's editing it down in a crash.

What XML Does

XML documents use elements to define their structure and nested child elements to define subsidiary aspects of their basic building blocks, attributes to describe document data, DTDs or Document Type Definitions to describe valid document components, and entities to represent extended characters from beyond the basics of ASCII typesetting, including accented characters and special punctuation. Because XML doesn't concern itself with the appearance of the data it structures, you can establish a project in XML and use it as the basis of numerous forms of output, from HTML to the printed page.

XML and InDesign

Importing XML into an Adobe InDesign document uses a process similar to the act of placing a text or word-processing file. Its options enable you to make choices about what gets imported from the XML file and what happens to the content you bring in. Once your content reaches the document window, InDesign's Structure panel shows you the definitions and instructions in your imported file and enables you to incorporate them into the pages of your layout file.

InDesign Benefits

Because XML defines data but not its appearance, you can set up an Adobe InDesign layout with paragraph, character and object styles that suit your XML document, correlate these styles with your XML structure and create a production-ready document simply by importing an XML file. For the same reason, you can create one XML file that produces multiple InDesign projects, each with completely different styles and appearance attributes, each using differing amounts of the content from the XML source. One XML document thus becomes the basis for a broadly distributed cross-media plan to support marketing, product distribution or any other effort, including product brochures, sales flyers, specification sheets and web content.

References

• Adobe Systems: Using Adobe InDesign CS5 & CS5.5
• XML.com: Adobe's InDesign and XML
• A Designer's Guide to Adobe InDesign and XML; James J. Maivald and Cathy Palmer

Resources

• Real World InDesign CS5; Olav Martin Kvern and David Blatner
• InDesign CS5 Bible; Galen Gruman