[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Advice needed on placement of XML datatype validation methods
Amit Rekhi wrote: > I am in the process of attaching datatype validation routines > for element content in my XML file. I have come up with 2 approaches (as > listed below)., but am not sure which is a better one. If someone could > give their expert opinions .... > > > APPROACH 1 > > I can use NOTATIONS to identify data validation processes with element > content. eg. > > <?xml version="1.0" ?> > <!DOCTYPE start-ele [ > <!NOTATION Alphabet SYSTEM "AlphabetChecker.vld"> > <!NOTATION Number SYSTEM "NumberChecker.vld"> > > <!ELEMENT start-ele (#PCDATA)> > <!ATTLIST start-ele datatype NOTATION (Alphabet|Number) "Alphabet"> > ]> > <start-ele datatype="Number">123</start-ele> > > where AlphabetChecker.vld and NumberChecker.vld could contain validation > routines for checking alphabet and number datatypes. > > > APPROACH 2 > > I embed my datatype validation scripts in the XSL file I attach to my XML > data.I can embed my datatype validation scripts in HTML which will be > outputted by my XSL file (I am using XSL to do XML -> HTML transformation) > for elements in the XML file. In this case I could possibly use > (JScript/VBScript/JavaScript) as languages to implement my datatype > validation routines. > > Which of the 2 approaches is better? > > These 2 approaches bring out the basic questions:- > > Where to place datatype validation routines for element content, in the > XML-DTD or in the XSL file attached to the XML data? Of the two, I would probably use notations -- XSL is not yet finished and really has nothing to do with data types. However, you should not assign the data type on a per-element-instance basis as your example shows. This takes up extra space and is prone to errors -- element foo is a number in one case and alphabetic in another, which is probably not what you want. Instead, add a dt attribute for each element type and assign a fixed default. This way, the data type is fixed for a single element type. Eventually, this information should go in a schema file (XSchema/DCD) and a validating processor (or layer) will use built-in routines to do the checking. If you are going to assign datatype attributes, you ought to look at/use the data types in DCD. -- Ron Bourret xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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