Record format documents and RFML syntax

RFML documents, called RFML source files, contain tags that define the specification for a particular data format.

Because RFML is based on PCML, the syntax is familiar to PCML users. Because RFML is an XML extension, RFML source files are easy to read and simple to create. For example, you can create an RFML source file by using a simple text editor. Also, RFML source files reveal the structure of the data in a way that is easier to understand than in a programming language like Java™.

The RFML example Using RFML compared to using IBM^® Toolbox for Java Record classes includes an example RFML source file.

RFML DTD

The RFML document type definition (DTD) defines valid RFML elements and syntax. To ensure that an XML parser can validate your RFML source file at runtime, declare the RFML DTD in the source file:

<!DOCTYPE rfml SYSTEM "rfml.dtd">

The RFML DTD resides in the jt400.jar file (com/ibm/as400/data/rfml.dtd).

RFML syntax

The RFML DTD defines tags, each of which has its own attribute tags. You use the RFML tags to declare and define the following elements in your RFML source files:

The rfml tag begins and ends the RFML source file that describes the data format.
The struct tag defines a named structure that you can reuse within the RFML source file. The structure contains a data tag for each field in the structure.
The recordformat tag defines a record format, which contains either data elements or references to structure elements.
The data tag defines a field within a record format or structure.

In the following example, RFML syntax describes one record format and one structure:

<rfml>

    <recordformat> 
        <data> </data>
    </recordformat>

    <struct> 
        <data> </data>
    </struct>

</rfml>

RFML document type definition (DTD)
This is the RFML DTD. Note that the version is 4.0. The RFML DTD resides in the jt400.jar file (com/ibm/as400/data/rfml.dtd).
The RFML data tag
The data tag can have the following attributes.
The RFML rfml tag
The rfml tag can have the following attributes.
The RFML recordformat tag
The recordformat tag can have the following attributes.
The RFML struct tag
The struct tag can have the following attributes.

Parent topic: Record Format Markup Language