Xml Pcdata Vs Attribute

How do you chose what to make #PCDATA and what to make an attribute? Here's a rule: If it is data meant to be displayed or processed by the application, use PCDATA. Only use tags for meta-data (data about the data). Here's an example: Suppose you have some text to be displayed by an application. If the user clicks on the text, you want the application to either make a noise or not. Do it like this:

<!DOCTYPE text
        [
        <!ELEMENT text #PCDATA>
        <!ATTRIBUTE text beep (yes | no) #REQUIRED>
        ]
>

<text beep="yes">
        Here is the text to be displayed.  Whether the text beeps or
        not is NOT displayed -- that's why it's an attribute.
</text>

References:

• http://www.oasis-open.org/cover/elementsAndAttrs.html
• http://java.sun.com/xml/docs/tutorial/overview/4_design.html

This page might be more accurately titled XmlPcDataVsXmlCdata

That guideline works fine if the xml is document based. More and more, xml is being used as a data structure. Our rule is that basic data types and typecodes are attributes, objects map map to elements. Elements that define relationships wrap subelements. IOW,

<facility unLocCode='us.fou' facilityId='cfs12'>
        <facilityOperator>
                <party code='party2.com'/>
        </facilityOperator>
</facility>

--JackBolles

CategoryXml CategoryPattern CategoryComparisons XmlPattern ExtensibleMarkupLanguage