Validating XML with RELAX (3)

Validity and RELAX

<<< Of course, just because an English sentence has proper spelling, grammar, and punctuation doesn't make it meaningful:

The brick astonished the sunlight.

Similarly, there are some questions about the weather report that the DTD can't answer:

Does the wind <direction> have a valid value?
Is the <station>'s abbrev= attribute in the proper format?
Are the values for <latitude> and <longitude> in a valid range?

To be able to do this level of validation, Mr. Makoto Murata has invented RELAX, a markup language that lets you describe how other XML languages are to be validated. Since RELAX is itself in XML, it's much easier to read than a DTD. [Note: This material is based on the How to RELAX tutorial.] Let's start with the skeleton of a RELAX document to describe EWEML.

<module
           moduleVersion="1.2"
           relaxCoreVersion="1.0"
           targetNamespace=""
           xmlns="http://www.xml.gr.jp/xmlns/relaxCore">
<interface>
    <export label="report"/>
</interface>

Since we are using XML tags to define another set of XML tags, the attributes in the opening <module> tag establish namespaces so that we can know whose tag names are whose.

The <interface> tag specifies the name of the “root element” of our EWEML documents.

Now let's fill in more of the RELAX document. >>>