XML Facilities

The Extended Markup Language (XML) provides a standardized format for exchanging information. Uniface uses XML to import and export Repository data as well-formed XML, and to communicate between components using XML streams. It also provides a variety of ways to read, write, parse, and manipulate XML so that you can convert and transform it into other formats and data structures.

Uniface provides functionality exporting and importing repository data as XML, for generating and defining DTDs, writing and reading XML streams and files, validating and parsing XML, transforming XML using XSLT, and for reconnecting disconnected record sets (for example, in web applications).

Uniface supports two approaches to inter-component communication:

• Declarative XML handling is a simple way to write and read XML streams using Uniface-compliant DTDs. Uniface provides built-in parsing to write, read, and validate XML streams. The structure of the XML streams is determined by Uniface, and any XML it reads must comply to that structure.
• Procedural XML handling provides complete flexibility, so the XML data does not need to conform to Uniface's own DTD. Instead, you can transform any XML into a format that is appropriate for your purposes. For example, you can generate or read XML data required by non-Uniface sources such as web services.

You can mix and match approaches as required. For example, you can convert an XML document to a Struct, and manipulate it to create another Struct that can be loaded into a component data structure. Or you can transform it into Uniface-compliant XML that is loaded into a component.

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