RE: can attribute in XML schema hold value and unit

-----Original Message-----
From: Sreeni Yetchina -X (syetchin - Pure Solutions at Cisco) [mailto:syetchin@c...]
Sent: Friday, March 03, 2006 2:31 PM
To: Bullard, Claude L (Len); Mangesh Kalbhor; xml-dev@l...
Subject: RE: can attribute in XML schema hold value and unit

From the design perspective, I agree with "Len".

The best is to separate these two values(numerical and units) . But this is possible if you are starting the Schema afresh.

but if the XML instance documents are already existing and we need to write a Schema for them and some how to validate, we can follow the method that I narrated in my last email(defining a regular expression constraint on the Simple type of attribute definition in the schema)

Thanks,

Sreeni

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From: Bullard, Claude L (Len) [mailto:len.bullard@i...]
Sent: Friday, March 03, 2006 12:24 PM
To: Mangesh Kalbhor; xml-dev@l...
Subject: RE: can attribute in XML schema hold value and unit

 

<FlowRate unitStuff="GPM 100" />

 

The best answer is, don't do that; it's bad design for

reasons that are obvious (esentially, it is a token delimited

list and has all the same problems of production order,

catching errors late, all strings, etc.)

 

Make two attributes: one for unitType and one for unitValue. 

 

<FlowRate unitValue="100" unitType="GPM" />

 

It's clear and better for production and validation.

If these are basic types, say enumeration for the

unitTypes and numbers for the values, attributes will work

but are the least extensible.

 

A FlowRate element with an enumerated attribute for unit type.

 

<FlowRate unit="GPM">100</FlowRate>

 

Dealer's choice but the last one is the most robust.

 

len

-----Original Message-----
From: Mangesh Kalbhor [mailto:Mangesh.Kalbhor@a...]
Sent: Friday, March 03, 2006 2:08 PM
To: xml-dev@l...
Subject: can attribute in XML schema hold value and unit

Hi All,

 

I am creating a xml schema where I have to making a ‘attribute’ but can a attribute hold a value and unit.

My example is FlowRate, let’s the value and unit could be 100 GPM.

Can I have just one attribute for 100 and GPM both. Some times it might be 80 cFPS.

 

So can a attribute hold both or do I need element here.

 

Thanks,

 

Mangesh