The existence of billions of websites in the World Wide Web has made internet surfing a daily routine for almost all people in the world. Some users do not care about the interface and content of the websites they visit as long as they found what they needed, but for concerning bodies such as the World Wide Web Consortium (W3C), websites that have errors in their interface and content, should be fixed, and should be a big concern for the developer side. Through the recommendations of W3C for the XSLT Validator, the problems encountered can be altered and therefore, be validated.The existing XSLT Validator is concerned with XML, DSD, XML Schema and XSLT.
Extensible Mark-up Language (XML) is widely used in creating websites. Its primary purpose is to help information systems share structured data, particularly via the Internet, and it is used both to encode documents and to serialize data.
XML Schema is used to express a schema: a set of rules to which an XML document must conform in order to be considered 'valid' according to that schema that was also designed to the intention of determining a document's validity.
W3C then developed the Extensible Stylesheet Language Transformations (XSLT) that is used for the transformation of XML documents into other XML or "human-readable" documents. The original document is not changed; rather, a new document is created based on the content of an existing one. [www.w3c.org]
Because of the disadvantages faced by developers using XML Schema such as it cannot require a specific root element, the character data cannot be constrained in any way. The group has decided to tap the power of a new schema that is more powerful than that of the XML schema, known as the DSD (Document Structure Description) schema.
Document Structure Description (DSD) is an XML Schema language co-developed by AT&T Labs - Research, NJ, and BRICS, University of Aarhus, Denmark. The goal of DSD is to provide schema syntax capable of strong data typing and context-dependent content models. The DSD site provides free source code, a meta-DSD that can be used to validate DSD schemas, and an XSLT stylesheet that can be used as a default stylesheet for instances of XML documents conforming to a DSD schema for outputting HTML. [www.briks.dk]. Today, there is already a new and improved version of DSD which is DSD 2.0. [www.xml.com]
DSD 2.0 is designed to contain few and simple language constructs, be easy to understand, also by non-XML-experts and have more expressive power than other schema languages for most practical purposes. It has many advantages over the XML schema, which is the standard schema at present, some of which are 1) DSD rules can be hierarchical by depending on attribute values and element context 2) DSD is 100% self-describing 3) Lots of non-essential features that can be seen in the XML schema are removed or reduced to more basic and general constructs. [Moller and Schwartzbach 2006]
Currently there is no validator for XSLT using the DSD 2.0 schema thus the power of the DSD 2.0 schema cannot be utilized. This study would focus on creating an XSLT validator that uses the DSD 2.0 schema. If the XSLT is invalid it would have output error messages and a valid confirmation if the XSLT is valid as the output. Since the XML file can be translated to different formats, there can be many possible outputs such as the XHTML and HTML file format.
Extensible Hypertext Markup Language, or XHTML, is a markup language that has the same depth of expression as HTML, but also conforms to XML syntax. [www.zimbio.com]
While HTML is an application of Standard Generalized Markup Language (SGML), a very flexible markup language, XHTML is an application of XML, a more restrictive subset of SGML. Because they need to be well-formed, true XHTML documents allow for automated processing to be performed using standard XML tools—unlike HTML, which requires a relatively complex, lenient, and generally custom parser. XHTML can be thought of as the intersection of HTML and XML in many respects, since it is a reformulation of HTML in XML. [www.indigodigital.com]
Applications on the Web are now moving in the direction of XML. Using XHTML now instead of HTML makes any future transition of any website easier. Once browsers offer support for XHTML documents and the strict rules of XML, they will become quicker thanks to shorter error processing routines. At present, a great deal of the processing power of a browser is still spent on liberal error processing of documents containing malformed HTML markup. This is the price of a quickly but chaotically expanding internet.
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