Cart
|
[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: Validating documents against XML Schema with different nam
 Aha! A fairly simple, yet elusive answer. Where does it say that validateOnParse (default true) only does a lax validation? That could have saved me a lot of trouble. Anyway, thank you very much for the examples and quick reply! My faith in MSXML is restored (for the moment...). Strangely, though, I can't get a decent error message by using your "validate()" trick. That is, I get one of two messages, depending on whether I lack the correct namespace or having correct namespace+invalid data. The ones I get are: "Validate failed because the root element had no associated DTD/schema." (-1072897500) "Validate failed because the document does not contain exactly one root node." (-1072897501) These messages are obvious enough, even the latter one, because trying to output the XMLDoc.xml property when having an invalid document yields only an empty string. Thus, the document does of course lack a root node. It's somewhat strange though, giving just that message, and not one where it says exactly WHAT is wrong, and not only describing the symptoms of the error. This means that for proper error logging, I have to combine the two approaches, by both checking the parseError.errorCode after load, and if that's OK, also perform the validate() and see if that fails. That way I can log any schema violations with a decent error message, providing the document uses the correct namespace, and finally trapping the cases where the namespace itself is incorrect. Case closed, I'd presume. Mvh / Kind regards, Morten Grøtan morten.grotan@e... Utvikler, MCSD Electric Farm ASA, Rosenkrantz gt. 21, NO-0160 OSLO, Norway, http://www.electricfarm.no/ mob: +47 92 88 59 72, tel: +47 48 00 09 99, fax: +47 23 10 30 10 -----Original Message----- From: Dare Obasanjo [mailto:dareo@m...] Sent: 30. september 2002 11:04 To: Morten Grøtan; xml-dev@l... Subject: RE: Validating documents against XML Schema with different namespace using MSXML Calling the validate( ) method on the document is the preferred way to use MSXML to validate a document since it does strict validation while loading with validateOnParse set to true does lax validation. I could not reproduce the results of your scenarios using MSXML 4.0 SP1 when I called validate() directly. Below are the code, XML instance and schema I used var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.4.0"); var xsdCache = new ActiveXObject("Msxml2.XMLSchemaCache.4.0"); xsdCache.add("", "example.xsd"); xmlDoc.async = false; xmlDoc.schemas = xsdCache; xmlDoc.load("example.xml"); var err = xmlDoc.validate(); if (err.errorCode == 0){ WScript.Echo("Document is valid"); }else{ WScript.Echo("Validation error:" + err.reason); } <?xml version="1.0" ?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="A"> <xs:complexType mixed="true"> <xs:choice> <xs:element name="B" /> <xs:element name="C" /> </xs:choice> </xs:complexType> </xs:element> </xs:schema> <?xml version="1.0"?> <A xmlns="http://www.example.com" > foo <C /> foo </A> -----Original Message----- From: Morten Grøtan [mailto:Morten.Grotan@e...] Sent: Mon 9/30/2002 1:29 AM To: XML Dev List (xml-dev@l...) Cc: Subject: Validating documents against XML Schema with different namespace using MSXML Hi, I've only just started using XML Schemas with the MSXML parser (4.0 SP1), and have trouble grasping a few baseline things. The real-life task I set out to solve with XML Schemas was to be able to validate documents prior to importing to a production database. The documents are received as part of an automatic collector service, hence I don't have 100% control of what kind of files are received. I want to be able to only import 100% valid documents, according to my schema, and avoid having tons of custom validation logic within my import program. Making the schema itself for a given instance of a typical valid document has proved to be no problem, and I am also able to enforce the constraints specified in my schema. So far so good. But what happens is that I purposely place an invalid document among the other valid ones, to see what happens. The real problem, I've found, is in the use of namespaces (what a surprise, having read lots of different articles about namespaces lately....). I have defined both a default and a target namespace in my schema and everything works just fine as long as I have the same namespace in my instance document. But as soon as there is the slightest mismatch in namespaces, the document is NOT validated against the schema, hence rendering my validation mechanism utterly useless. I've sketched out 4 scenarios below, using the following terminology: xsd: An XML Schema xml: An XML instance document xmlns: Default namespace targetns: XML Schema target namespace Scenario 1: xsd: no xmlns and no targetns xml: no xmlns uses xsd and correctly says invalid xml is invalid Scenario 2: xsd: no xmlns and no targetns xml: xmlns set to something else than targetns does NOT use xsd and incorrectly says invalid xml is valid Scenario 3: xsd: xmlns and targetns xml: xmlns uses xsd and correctly says invalid xml is invalid Scenario 4: xsd: xmlns and targetns xml: no xmlns or xmlns set to something else than targetns does NOT use xsd and incorrectly says invalid xml is valid The way I've implemented this is using the MSXML2.XMLSchemaCache.4.0 object to add a schema, associating it with the namespace defined in the schema, and then setting the "schemas" property of the XMLDom object (MSXML2.DOMDocument.4.0) to point at the XMLSchemaCache object. Then I just call the load method of the XMLDom object, and check the parseError object of the XMLDom object for any errors. So, why does this happen? Shouldn't MSXML be able to find out that my instance document does not share the same namespace as my schema, hence invalidating the document? What is the purpose of the whole XML Schema shebang elsewise? If you can't be sure that invalid documents are in fact invalidated, without writing tons of validation code yourself, why even bother using a schema? Needless to say, I'm slightly disillusioned right now, and possibly soon will be having a problem with my boss, trying to explain why I've wasted so much time on this schema thing without producing a useful validation mechanism..... As for the XMlSchemaCache object, I'm aware that you can add several schemas into it before attaching it to the XMLDom object, hence using all the schemas to validate the instance document. Admittedly it can seem hard to see which (if any) schema should be responsible for invalidating the document, but in my opinion ANY of them should be able to do that, as long as they can't be validated against the document. So, if at least one of the added schemas fail, the whole validation should fail. Or am I totally naïve? Mvh / Kind regards, Morten Grøtan morten.grotan@e... Utvikler, MCSD Electric Farm ASA, Rosenkrantz gt. 21, NO-0160 OSLO, Norway, http://www.electricfarm.no/ <http://www.electricfarm.no/> mob: +47 92 88 59 72, tel: +47 48 00 09 99, fax: +47 23 10 30 10 
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! 
Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|
|||||||||
