RE: Using Wrapper Elements in Schemas - Any Best Practices?

-----Original Message-----
From: Magick, Brian [mailto:Brian.Magick@COMPAQ.com]
Sent: 24 September 2001 15:38
To: xml-dev@lists.xml.org
Subject: [xml-dev] Using Wrapper Elements in Schemas - Any Best Practices?

Are there any best practices for using wrapper elements in XML Schemas?  We are having an internal debate on the merits of using wrappers, I summarize my opinions below.

The debate……should a set of symptoms be represented by a series of symptom tags alone or should they be contained in a <symptoms> wrapper element.

 

<symptoms>

<symptom> This is symptom 1 </symptom>

<symptom> This is symptom 2 </symptom>

<symptom> This is symptom 3 </symptom>

</symptoms>

 

My initial thoughts:  I think wrappers are useful when you need to group some tags and possibly need a lead wrapper element to capture some attributes or metadata.  For example (yes this might be a bit silly) perhaps we want to know the symptoms based on how long they have been persisting.  Maybe some symptoms have been around for 7 days and other for just 3.  The following XML, using wrapper elements, accomplishes the description of this quite well.

 

<symptoms duration=”3”>
  <symptom>cough</symptom>
  <symptom>sneezing</symptom>
  <symptom>runny nose</symptom>
</symptoms>

<symptoms duration=”7”>
  <symptom>dizziness</symptom>
  <symptom>stomach ache</symptom>
</symptoms>

 

Of course, this is just my opinion, and one I would like some community backing for before I espouse this as a “best practice” within my organization.  This might just be a matter of style, but I’m interested in how other developers are determining this.

 

Brian Magick