Tutorial 3 validating an xml document
Accordingly, the implementation method of the validation tool actually used is followed.However, under the XML Schema specification, there is a defined method for writing a hint to associate with the XML document.LIST1: Employee Information DTD As you see, the syntax is completely different between the two.For the DTD, a unique syntax is written, whereas the XML Schema is written in XML format conforming to XML 1.0 syntax.Now, we can provide a schema definition using actual schema definition language.LIST1 is an example using DTD and providing a schema definition for the content above, while LIST2 is an example using XML Schema to provide a schema definition (employee.xs).The schema element is used as the root element, and the XML Schema "Namespace" is declared.Namespace is a specification used to avoid the duplication of attribute and element names defined under XML, and is normally designated using URL format.
LIST4: Element Declaration Reference for a Model Group Element The element reference syntax is as follows: When declaring an attribute, the ATTLIST keyword is used under DTD, while the attribute element is used under XML Schema. As mentioned previously in connection with Complex Type declarations, when describing an attribute, the convention is to describe it after the Complex Type definition content (after the Model Group) (Line 19).Traditionally, DTD has been the standard for XML schema definition; however, XML usage has expanded dramatically in core application systems, being tailored for a wide range of purposes for which DTD is not fully capable of supporting.Given this development, the W3C recommended "XML Schema" as a schema definition language to replace DTD.These can be combined and extended or restricted to create new, unique data types.Note: The XML Schema specification consists of "Part 1: Structure Specification" and "Part 2: Data Type Specification." The embedded simple type is a data type already stipulated in "Part 2: Data Type Specification." In addition to what is shown in Table 2, there is also an "xs: hex Binary" data type that represents hexadecimal binaries and an "xs:base64Binary" data type that represents Base64 format binaries.
Seiichi Kinugasa In this and the next two volumes, we will discuss "XML Schema," a common schema definition language.