Using UD6 for EDI/XML Data Interchange

UD6 is a database that can be used with Uniface. Any data can be stored using UD6, including the Uniface repository (source code). However, there are some very good reasons for using UD6 for storing data that you want to interchange with other systems:

• Dynamic filenames.
• Data from multiple entities stored in a single file.
• Creating data is as simple as using store/e "entity-name".
• Can create data using command line $idf /cpy def:source.schema ud6:
• Data is in industry standard XML format.
• XML Data is self-describing, with associated XML Schema file.
• XML Data contains information that explains the relationships in your data (XLINK/XPTR).

Doesn’t Uniface 7.2.05/06 come with an Import/Export facility for XML?

If you are using Uniface 7.2.05/06, there is an in-built XML import/export function, however its disadvantages include:

• It is not designed or documented for your applications to dynamically export data from.
• Cannot provide selection criteria.
• The XML format is non-standard.
• The generated XML is not self-describing (because it uses a non-standard format).
• Does not provide relational information in the XML that it produces.
• Encodes the characters in TRX, rather than a character set (see NLS support in UD6/Cmtool).

What's different between UD6 XML and Uniface 7.2.06/Uniface 8 XML Streams?

If you are using Uniface 7.2.06 or Uniface 8, there is an in-built facility for writing and reading XML files for the purpose of data interchange. This is named XMLSTREAMS. UD6 may be a better XML tool for you if you require:

• National Language Support.
• Unicode Support.
• Relational information in the XML (XLINK/XPTR).
• XML Schema Support.

Which versions of Uniface are supported?

All Uniface version 6, 7 and 8 versions are supported, on all platforms. Uniface 5 support can be provided when required.

What industry standards does UD6 conform to?

Since XML is designed for information interchange, compliance with relevant standards is your guarantee that your data will be readable by your client.

March Hare are continually improving the standards compliance of the UD6 product. Emphasis is placed on standards that are being implemented in commercial applications, like web browsers and XML parsers.

At the moment Microsoft’s interpretation of the W3C standards are the major ones supported, which gives our users access to all of Microsoft’s XML tools. As the final drafts of the W3C standards are approved and implemented in commercial applications, March Hare will provide driver option settings for users to indicate which data format they wish to use, either IE5, or W3C.

Our intention is to support the following standards:

• XML (XML-Data)
  http://www.w3.org/TR/REC-xml (http://www.w3.org/TR/1998/NOTE-XML-data/)
• XML Namespaces
  http://www.w3.org/TR/REC-xml-names
• XML Schema
  http://www.w3.org/TR/xmlschema-1/]
• XML Datatypes
  http://www.w3.org/TR/xmlschema-2
• XML Pointer
  http://www.w3.org/TR/xptr
• XML Link
  http://www.w3.org/TR/xlink/
• XHTML
  http://www.w3.org/TR/xhtml1/

Links to Microsoft’s documentation of their implementations are:

• XML Namespaces
  http://msdn.microsoft.com/xml/xmlguide/namespaces-overview.asp
• XML Schema
  http://msdn.microsoft.com/xml/xmlguide/schema-overview.asp
• XML Datatypes
  http://msdn.microsoft.com/xml/xmlguide/schema-datatypes.asp

March Hare will also support the dynamic generation of XSL/XSLT when UD6 is used to store the Uniface repository (the Microsoft XSL standard is the only one currently supported). For information on how to use UD6 with Microsoft’s MSXML3.DLL (XML SDK) click here.

• W3C Standard:http://www.w3.org/TR/xsl/
• Microsoft:http://msdn.microsoft.com/xml/xslguide/default.asp

How do I store data in XML?

Firstly you need to download and install the March Hare UD6 driver from http://march-hare.com

Then follow this simple example, which stores user entered data in XML format:

• Modify assignment file
• Modify the UD6 xlink file
• Write and compile a Uniface form component
• Run form component

Here is our example data model:

What modifications do I make to my assignment file?

You need to add a line in the driver options settings, and a line in the Entities section to indicate which entities you will store in XML format. In this example, all the entities in the application model (Conceptual Schema) MYAPP are stored in XML format, in a file called MYAPP.XML.

The driver setting xmlschema ie5 tells the driver that it should automatically create a file called myappSchema.XML which describes the data in the MYAPP.XML file. NOTE: The relationship information is stored in the MYAPP.XML file as XLINK tags.

[ENTITIES]
*.MYAPP       $ud6:MYAPP.*

[DRIVER_SETTINGS]
USYS$UD6_PARAMS=xmlschema ie5

What is the ud6 xlink file, and what changes do I make to it?

The xlink file is a ud6 configuration file that is stored (by default) in the Uniface bin directory. It contains a list of entity relationships that are then used to create XLINK tags in the XML data file.

CUSTOMER:CUSID:ADDRESS:CUSID:cusaddress::::*
CUSTOMER:CUSID:INVOICE:CUSID:cusinvoice::::*
ADDRESS:CUSID:CUSTOMER:CUSID:parent::::*
INVOICE:CUSID:CUSTOMER:CUSID:parent::::*
INVOICE:INVID:INVLINE:INVID:detail::::*
INVLINE:INVID:INVOICE:INVID:parent::::*

Write and compile then run a Uniface form component

In our example, we make a form component where a user enters the data to be stored. However, any Uniface proc can be used, just treat the entity being stored in XML format just like any other entity in a database. To copy fields from one entity to another use the getlistitems/putlistitems proc statements.

What does the data look like ?

Click here for the MYAPP.XML file generated from the above example

Click here for the myappSchema file generated from the above example:

How do you dynamically alter the filename ?

This is accomplished by sending the UD6 driver an instruction using the sql proc statement. For example, using the form component defined earlier, to name the file EDIFILE.XML, we added this code to the form’s execute trigger:

sql ":MYAPP:none:EDIFILE.XML","ud6"
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