http://www.xmlforasp.net/schemavalidator.aspx
http://www.zvon.org/xxl/XMLSchemaTutorial/Output/ser_over_st0.html
We can override the schema declaration when setting xsi:nil attribute to value "true". The schema must allow this by setting attribute "nillable" to "true" (default value is "false").
Valid document < root xsi:noNamespaceSchemaLocation= "correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" > < e1>xxx</ e1> </ root> Valid document < root xsi:noNamespaceSchemaLocation= "correct_0.xsd" xsi:nil= "true" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" /> Invalid document < root xsi:noNamespaceSchemaLocation= "correct_0.xsd" xsi:nil= "true" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" > < e1>xxx</ e1> </ root> Invalid document < root xsi:noNamespaceSchemaLocation= "correct_0.xsd" xmlns="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" /> | Correct XML Schema (correct_0.xsd) < xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" > < xsd:element name= "root" nillable= "true"> < xsd:complexType> < xsd:sequence> < xsd:element name= "e1" type= "xsd:string"/> </ xsd:sequence> </ xsd:complexType> </ xsd:element> </ xsd:schema> |
2. Relax NG
There is no such mechanism in Relax NG.