All About Managing and Transforming XML Content

XML lies at the heart of many content management and publishing systems across various domains. This blog unpacks the essential components involved: CMS, DTD, XML, and XSLT, and discusses how they work together to create modular and reusable content.

%%{init: {'theme':'base', 'flowchart': {'layout': 'elk'}}}%% flowchart TD %% CMS boundary subgraph CMS ["CMS"] XML(["XML Document"]) DTD(["DTD / XSD"]) Metadata(["Metadata"]) VARIABLES(["KeyDefs / DITAVALS"]) Assets(["Assets"]) XSLT(["XSLT"]) XPath(["XPath"]) Processor[["XSLT Processor / DITA-OT"]] end %% Outputs boundary OutputXML(["Transformed XML"]) HTML(["HTML"]) MD(["Markdown"]) PDF(["PDF"]) %% Relations (split edges for compatibility) DTD <--> XML XML <--> VARIABLES XML <--> Metadata XML --> Processor XML --> Assets XSLT --> Processor XPath --> Processor Processor --> OutputXML Processor --> HTML Processor --> MD Processor --> PDF %% Base styles and classes classDef artifact fill: #b4d1aa,stroke: #000,stroke-width:1.5px,color: #000,rx:6,ry:6 classDef component fill: #f4c9a1,stroke: #000,stroke-width:1.5px,color: #000,rx:6,ry:6 classDef activity fill: #f5d8bd,stroke: #000,stroke-width:1.5px,color: #000,rx:6,ry:6 classDef asset fill: #a7d8ea,stroke: #000,stroke-width:1.5px,color: #000,rx:6,ry:6 classDef outputxml fill: #c8f1c8,stroke: #000,color: #000,rx:6,ry:6 classDef html fill: #bbdefb,stroke: #000,color: #000,rx:6,ry:6 classDef pdf fill: #f9b3aa,stroke: #000,color: #000,rx:6,ry:6 classDef md fill: #d3b8ea,stroke: #000,color: #000,rx:6,ry:6 %% Override colors - applied last for emphasis style XML fill:#00C853 style DTD fill:#C8E6C9 style Metadata fill:#C8E6C9 style VARIABLES fill:#C8E6C9 style Assets fill:#FFD600 style XSLT fill:#FFE0B2 style XPath fill:#FFE0B2 style Processor fill:#FF6D00 style OutputXML fill:#C8E6C9 style HTML fill:#BBDEFB style MD fill:#E1BEE7 style PDF fill:#FFCDD2 %% Assigning classes class XML,DTD,Metadata,VARIABLES artifact class Assets asset class XSLT,XPath activity class Processor component class OutputXML outputxml class HTML html class PDF pdf class MD md

Let’s explore the abbreviations

CMS (Content Management System)

A platform to create, store, manage, and publish content efficiently.

DTD (Document Type Definition)

Rules that define the structure, allowed tags, and attributes of an XML document. DTD validates the XML’s structure but does not support data types or namespaces.

XSD (XML Schema Definition)

A modern alternative to DTD, XML-based schema language that defines and validates the structure, tags, attributes, data types, and relationships in an XML document. It supports namespaces and complex data validation.

XML (Extensible Markup Language)

A flexible text format that uses custom tags to structure data, designed to be both human and machine readable.

Metadata

Essential information about the XML document itself, such as its properties or descriptive details.

KeyDefs / DITAVALS (Variables)

Named placeholders or values used in XML content to enable modular reuse and customization. For example, content can vary by product version or model, and variables allow you to mark those differences in the source XML and publish selectively.

Assets

External supporting files linked to XML content like images, videos, or PDFs.

XSLT (Extensible Stylesheet Language Transformations)

A language used to transform XML documents into other forms like HTML, PDF, or markdown by applying a set of transformation rules.

XPath (XML Path Language)

A query language used within XSLT to locate and select parts of an XML document for precise transformation. XPath lets XSLT precisely pick which parts of the XML to transform or output, based on criteria.

XSLT Processors

Software that apply XSLT stylesheets to XML data to produce output documents in various formats. DITA-OT is a sophisticated transformation toolkit.

Putting It All Together

Your XML documents are stored in a CMS, where the DTD or XSD ensures the XML follows the correct structure. Variables help customize and reuse content efficiently. XSLT processor then transforms XML into output formats such as HTML, Markdown, or PDF.

Industry Use Cases

DITA is widely adopted in software documentation. Aerospace traditionally used ATA Spec 100 and iSpec 2200 but many have migrated to modern S1000D. Heavy engineering relies on S1000D, while shipbuilding follows Shipdex. Across these fields, XML is foundational for technical documentation.

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Keywords

XML XSLT DITA DITA-OT DTD XSD XPath XQuery Content Management System Technical Documentation XML Transformation