Validating xml with xsd
In practice, however, many schema validators are integrated with an XML parser.
There are several different languages available for specifying an XML schema. The primary purpose of a schema language is to specify what the structure of an XML document can be.
With XML Schemas, the sender can describe the data in a way that the receiver will understand. However, an XML element with a data type like this: Even if documents are well-formed they can still contain errors, and those errors can have serious consequences.
A date like: "" will, in some countries, be interpreted as 3. Think of the following situation: you order 5 gross of laser printers, instead of 5 laser printers.
In W3C XML Schema a specific number or range of repetitions of patterns can be expressed whereas it's practically not possible to specify at all in RELAX NG ().
Unlike W3C XML Schema, RELAX NG was designed so that validation and augmentation (adding type information and default values) are separate.As well as validation, XSD allows XML instances to be annotated with type information (the Post-Schema-Validation Infoset (PSVI)) which is designed to make manipulation of the XML instance easier in application programs.This may be by mapping the XSD-defined types to types in a programming language such as Java ("data binding") or by enriching the type system of XML processing languages such as XSLT and XQuery (known as "schema-awareness").These constraints are generally expressed using some combination of grammatical rules governing the order of elements, Boolean predicates that the content must satisfy, data types governing the content of elements and attributes, and more specialized rules such as uniqueness and referential integrity constraints.There are languages developed specifically to express XML schemas.