Best way to handle optional elements in XSLT

Question

Hi All,
I'v wondering if there are any better ways to handle optional fields in XSLT.
For example if my Person Type has 5 fields and 3 of them are optional:
<xs:complexType name="PersonType">
<xs:element name="PersonID" min="1"/>
<xs:element name="PIN" min="1"/>
<xs:element name="FirstName" min="0"/>
<xs:element name="MiddleName" min="0"/>
<xs:element name="LastName" min="0"/>
</xs:complexType>
In my xslt file, if I do somthing like:
<Person>
<FirstName>
<xsl:value-of select="PersonType/FirstName"/>
</FirstName>
</Person>
I might get an empty FirstName element in my output xml file. (like <FirstName/>) This has caused some very weired behavour with Oracle v2 parser because optional means the node may not be present in the xml not the node is there but empty.
The only way I can think of solving this is to put <xsl:if test> around every single optional element to test if it exist in the source file. If it does then generate the element in the destination file. But in this way, if the source file is very complicated, then you would have to wrap each element with a <xsl:test> which is very ugly to me.
Do anyone know if there is a more generic way that we can solve this issue?
Thanks,
Larry

Answer 1

Dharmendra,
The answer you gave is very very helpful. The only thing that I can think of here is that it might accidentally delete the fields that have been set empty deliberately.
Maybe, this is one of the grey areas in XML Schema that I do not understand very well yet. In xml, if you define an element to be a string type and mandatory (minOccurs="1"), for exampe the following xml
<Name></Name>
will be valid against the schema because the Name element is present in the xml payload. However, it has no value or has a valud of empty string. I know that this is only a problem with string type. If it is boolean, then it has to be either true of false, being empty won't satisfy the schema validator. But with String it is a bit trickier, because String can be empty. Maybe this issue should be stopped when designing your xml schema by specifying the mininum length (>0) in the schema. Any suggestions would be welcomed.
Cheers,
Larry