explains XML User Interface Language (XUL)

XUL is based on the core existing Web standards - CSS, DOM and JavaScript. XUL relies on Gecko implementations, and, hence, it is not interoperable with non-Gecko standards. XUL does not have any formal specification. Widgets running on the Mozilla platform can be developed using XUL and ported across different platforms. Components of XUL documents include: Content: The arrangement of UI components is defined in the documents that together constitute the contents of XUL files. Skin: Skin is regarded as the customizable set of colors or patterns that can be associated with a given XUL user interface defined in the form of skin files. It may include CSS and image files. Locale:Language changes can be incorporated in the user interface using internationalization and localization features provided by XUL.XUL files contain both XML and HTML elements in addition to XUL elements defined using the XUL namespace. A MIME type text/xul can be associated with XUL documents. An XUL interface defines a mechanism for programming a set of disconnected widgets. Simple scripting can be used like JavaScript, or complex C++ code can be used to define widget behavior.

What does XML User Interface Language (XUL) mean?

XUL is a user-interface language developed by Mozilla that enables developers to design cross-platform applications that can run in both online and offline modes. It is customizable using different graphics, text and layouts to support localized and internationalized markets.

explains XML Schema

XML schemas are expressed using Document Type Definition (DTD) language, which is native to the XML specification but with a fairly limited capability. An XML document can be associated with a schema language, either by markup in the XML document or through some external means.

The process of checking whether an XML document adheres to a schema is called validation. XML documents are valid if they satisfy schema requirements with which they are associated, including constraints such as:

• Structure as specified by a regular expression syntax
• Requirements for interpretation of character data
• Elements and attributes to be included along with their allowed structure

Definition - What does XML Schema mean?

An XML schema is the structural layout of an XML document, expressed in terms of constraints and contents of the document. Constraints are expressed using a combination of the following:

• Grammatical rules governing the order of elements
• Data types governing an element and content attribute
• Boolean predicates that the content has to satisfy
• Specialized rules including uniqueness and referential integrity constraints

explains XML Query Language (XQuery)

XQuery acts like an expression language since it specifies the exact flow of data and operations to achieve a desired result. It does not mention how the data is associated with a particular programming platform in terms of syntax. For example, an expression specifies the result value of an addition but does not deal with the declaration of variables, the data types used and commands or function calls.
XML documents can be created with the help of the syntax provided with XQuery. The XML documents are processed to extract structural information, which is classified as document nodes, elements, attributes, text nodes, comments, processing instructions and namespaces.

All data items or values are treated as sequences by default. Either atomic values or nodes are the type of data items present in an XML document. The atomic values like Boolean, integer and string are as per XML schema specification. Features such as full text based search and document updates are currently under development.

Definition - What does XML Query Language (XQuery) mean?

XML Query Language (XQuery) is a query and programming language for processing XML documents and data. XML data and other databases that store data in a format analogous to HTML can be processed with XQuery. The main objective of XQuery is to provide query mechanisms for data extraction from real and virtual Web based documents. It aims to link Web and database technologies with the help of XML.

The World Wide Web Consortium is responsible for framing XQuery 1.0.

explains XML Data Island

In an HTML document, the XML element is written as:

It signifies the beginning of the XML data island. Following this, an ID attribute may be inserted to identify the data island:

An XML data island may be created by three methods: Inline XML; using an XML tag and using the script tag.

Internet Explorer (IE) Mobile 6 is required for XML data islands to function properly; the same methodology may be used for IE Mobile 6.5.

Definition - What does XML Data Island mean?

An XML data island is an XML document residing within an HTML page. This avoids having to write code (i.e. a script) just to load the XML document, or having to load it through a tag. Client side scripts can directly access these XML data islands. These XML data islands can be bound to HTML elements also.

explains Extensible Markup Language (XML)

XML is designed to describe data but is not concerned with the data's visualization. The tags created in XML are self explanatory and the user is free to define their own tags - hence the extensible.
XML support is provided by many programming language platforms to create and process XML data. Simplicity, portability, platform independence, usability are some of the key features that have resulted in the increasing popularity of the use of XML based standards.
XML has been the main source of motivation for development of Service Oriented Architecture (SOA) platforms such as Web Services that are not tied to any particular language and collaborate effectively in heterogeneous environments. RSS, Atom, SOAP, XHTML are some of the standards influenced by XML.

Definition - What does Extensible Markup Language (XML) mean?

Extensible Markup Language (XML) is a universal format maintained by the W3C used for representation and transfer of structured data on the web or between different applications.
The language uses a structured representation by allowing user to create custom defined tags according to XML Document Type Definition (DTD) standards. The structure of XML document can be represented in the form of a tree known as Document Object Model (DOM).