CODEWITHSUNDEEP
xmldtd
John Rock
John Rock

Reputation: 133

Error validating DTD

I'm trying to write a DTD for an XML file.Here it is : https://prod-c2g.s3.amazonaws.com/db/Winter2013/files/courses-noID.xml

Here's my DTD 

    <!ELEMENT Course_Catalog (Department*) >
<!ELEMENT Department (Title*, Chair*, Course*) >
<!ATTLIST Department Code CDATA #REQUIRED >
<!ELEMENT Title ANY >
<!ELEMENT Chair (Professor) >
<!ELEMENT Professor (First_Name, Middle_Initial?, Last_Name) >
<!ELEMENT First_Name ANY >
<!ELEMENT Last_Name ANY >
<!ELEMENT Course (Title, Description?, Instructors, Prerequisites?) >
<!ATTLIST Course Number CDATA #REQUIRED Enrollment CDATA #IMPLIED >
<!ELEMENT Description ANY >
<!ELEMENT Instructors (Professor*, Lecturer?) >
<!ELEMENT Lecturer (First_Name, Middle_Initial?, Last_Name) >
<!ELEMENT Middle_Initial ANY >
<!ELEMENT Prerequisites (Prereq*)>
<!ELEMENT Prereq ANY >

Well it looks almost fine but there is a slight error.It says 'validity error : Element Instructors content does not follow the DTD, expecting (Professor* , Lecturer?), got (Lecturer Professor Professor )'.Isn't * means any number of elements?Why is there an error?

Upvotes: 1

Views: 2019

Answers (2)

Daniel Haley
Daniel Haley

Reputation: 52888

Isn't * means any number of elements?Why is there an error?

Yes, but the , is specifying an order. Your model (Professor* , Lecturer?) means zero or more Professor followed by zero or one Lecturer. The XML found an occurrence of one Lecturer followed by 2 Professor.

This model could be (Lecturer,Professor+), but it depends on what the other Instructors elements look like. Start with (Lecturer,Professor+) and "loosen" it as required.

Upvotes: 3

mortsahl
mortsahl

Reputation: 600

You probably should have written your DTD first ... but ...

Why don't you download the trial version of Stylus Studio that includes a DTD generator. http://www.stylusstudio.com/dtd%5Fgenerator.html

Upvotes: 0

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