Extensible Markup Language
XML - the Extensible Markup Language is an ISO-standardized markup language from the World Wide Web Consortium (W3C) that is used to represent hierarchically structured data in the form of textual data. XML is used for the platformindependent exchange of data between computer systems, in particular on the Internet.
W3C defines XML as a meta-language that can be used as a basis to define application-specific languages using structural and content limitations. These include XSL-FO (in particular in the field of printing and archiving), XHTML (for web-based applications), and SVG.
In XML, all elements are strictly structured using a method similar to the menu tree structure in Windows. A single introductory keyword (start tag) and concluding keyword (end tag) always determine the respective structure level (parentheses). XML is well suited to represent data in a structured way. What is absent is the connection to the printed document, which can be created using additional formatting information, be it through Cascading Style Sheets (CSS), a style language that defines the appearance of HTML documents, or Extensible Stylesheet Language Formatted Objects (XSL-FO), which describes how text, images, lines, and other graphical elements are to be arranged on a page, particularly those in documents that need to be printed or archived.
In appearance, XML somewhat resembles the Hypertext Markup Language (HTML) protocol commonly used on the Internet. The most important difference is that the symbols used in XML ("tags") can be freely selected from a wide range of options, while in HTML they are predefined. Special forms of XML can therefore be created for almost any application. As a result, XML has a broad range of uses.
Another benefit: XML is easy to generate, process, and can be expanded as required
Due to these advantages, XML is increasingly being used instead of SGML (Standard Generalized Markup Language) as the ISO standard for document representation. XML has a wide area of application, including in
- RSS feeds
- Logins for e-mail accounts (via SAML)
- XHTML-based web pages
- PowerPoint presentations
- Accounts for services
- Configuration files
Sectors with High Levels of XML Processing:
- Health and social sector
- Public administration
- Financial service providers
- ITC market
- Energy supply
Example 1: Technical Documentation
- Content is produced in DocBook (XML), for example
- Multichannel publishing using an XML workflow with XSLT
Example 2: Electronic Service Invoice in the Healthcare Sector (Switzerland)
- XML for electronic communication between service providers and payers
- Avoids media discontinuity and speeds up the processes
- Patient receives a PDF or paper document that has been produced by an external printing service provider
Source: Jeremias Märki, IT Software-Entwicklung und Beratung
Compart’s DocBridge product series, including the mixed format filter (MFF), can be used to convert XSL-FO, XHTML, OOXML and SVG into all common formats such as AFP, PostScript, PDF, IPDS, etc. XSL-FO documents are processed using the SAX process (simple API for XML). The file is read line by line. Once one page is finished, it is passed to the corresponding output filter.
Compart’s MFF filters (mixed format filter) are the basis of the MFF architecture for DocBridge products. Some MFF filters read files in different formats (input filters) while others are used to write files in the respective output format (output filters). In many cases, a format is supported for both input and output.
The strength of the Compart MFF architecture is its ability to quickly and effectively convert documents in various formats into others, or integrate them into a document using a specific format. For example, documents in AFP, SAPGOF or PCL can be converted to PDF and can also be merged into a single PDF document.
When converting one format into another, Compart uses the shared object format, the so-called presentation area (PA), which is able to represent the visual data and metadata of all supported formats. An MFF input filter converts an input file into the PA format in main memory and an MFF output filter then converts the PA format saved in main memory into an output file.
XML Conversion Directions
A complete overview of all supported input and output formats is provided in the Compart Matrix. Compart software solutions enables highly complex, single pass operations with flexibility and reliability for high availability, high volume environments.