Re: [xml-dev] Do not use the same tag name for different things ...Do yo

[Roger L Costello <costello@mitre.org>]

Michael Kay wrote:

	People don't often realise that in some cases
 	they are choosing a name that describes how
 	the element relates to its parent, and in other
 	cases they are choosing a name that describes
	what kind of thing it is (its type).

In the following XML, the element name "result" was chosen to describe how the <result> element relates to its parent (namely, test-case's expected results). Conversely, the element name "error-code" was chosen to describe a thing (namely, an error code), not a relationship.

<test-case name="B">
   ....
   <result>
      <error-code>XPTY0004</assert-eq>
   </result>
</test-case>

In the following XML, the element name "altitude" was chosen to describe how the <altitude> element relates to its parent (namely, the leg's altitude constraint). Conversely, the other element named "altitude" was chosen to describe a thing (namely, an altitude), not a relationship.

<leg>
    <altitude>
        <at-or-above>
            <altitude>29000</altitude>
        </at-or-above>
    </altitude>
</leg>

Do I understand correctly?

My example shows the same name (altitude) used in two different roles: (1) to describe a relationship to its parent, and (2) to describe a thing.

Is it bad data modeling to use the same name for two different roles?

/Roger