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| Cascading Style Sheets |
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In computing, the two primary stylesheet languages are Cascading Style Sheets (CSS) and the Extensible Stylesheet Language (XSL). While they are both called stylesheet languages, they have very different purposes and ways of going about their tasks.
CSS is designed around styling a document, structured in a markup language, HTML and XML (including XHTML and SVG) documents. It was created for that purpose. The code CSS is non-XML syntax to define the style information for the various elements of the document that it styles.
The language to structure a document (markup language) is a prelimit to CSS. A markup language, like HTML and less XUL, may define some primitive elements to style a document, for example <emphasis> to bold. CSS post styles a document to "screen media" or "paged media".
Screen media, displayed as a single page (possibly with hyperlinks), that has a fixed horizontal width but a virtually unlimited vertical height. Scrolling is often the method of choice for viewing parts of screen media. This is in contrast to "paged media", which has multiple pages, each with specific fixed horizontal and vertical dimensions. To style paged media involves a variety of complexities that screen media does not. Since CSS was designed originally for screen media, its paged facilities lacked.
CSS version 3.0 provides new features that allow CSS to more adequately style documents for paged display.
XSL has evolved drastically from its initial design into something very different from its original purpose. The original idea for XSL was to create an XML-based styling language directed toward paged display media. The mechanism they used to accomplish this task was to divide the process into two distinct steps.
First, the XML document would be transformed into an intermediate form. The process for performing this transformation would be governed by the XSL stylesheet, as defined by the XSL specification. The result of this transformation would be an XML document in an intermediate language, known as XSL-FO (also defined by the XSL specification).
However, in the process of designing the transformation step, it was realized that a generic XML transformation language would be useful for more than merely creating a presentation of an XML document. As such, a new working group was split off from the XSL working group, and the XSL Transformations (XSLT) language became something that was considered separate from the styling information of the XSL-FO document. Even that split was expanded when XPath became its own separate specification, though still strongly tied to XSLT.
The combination of XSLT and XSL-FO creates a powerful styling language, though much more complex than CSS. XSLT is a Turing complete language, while CSS is not; this demonstrates a degree of power and flexibility not found in CSS. Additionally, XSLT is capable of creating content, such as automatically creating a table of contents just from chapters in a book, or removing/selecting content, such as only generating a glossary from a book. XSLT version 1.0 with the EXSLT extensions, or XSLT version 2.0 is capable of generating multiple documents as well, such as dividing the chapters in a book into their own individual pages. By contrast, a CSS can only selectively remove content by not displaying it.
XSL-FO is unlike CSS in that the XSL-FO document stands alone. CSS modifies a document that is attached to it, while the XSL-FO document (usually the result of the transformation by XSLT of the original document) contains all of the content to be presented in a purely presentational format. It has a wide range of specification options with regard to paged formatting and higher-quality typesetting. But it does not specify the pages themselves. The XSL-FO document must be passed through an XSL-FO processor utility that generates the final paged media, much like HTML+CSS must pass through a web browser to be displayed in its formatted state.
The complexity of XSL-FO is a problem, largely because implementing an FO processor is very difficult. CSS implementations in web browsers are still not entirely compatible with one another, and it is much simpler to write a CSS processor than an FO processor. However, for richly specified paged media, such complexity is ultimately required in order to be able to solve various typesetting problems.
HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript.
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The World Wide Web Consortium's XML 1.0 Specification of 1998 and several other related specifications—all of them free open standards—define XML.
In computing, the term Extensible Stylesheet Language (XSL) is used to refer to a family of languages used to transform and render XML documents.
XSLT is a language originally designed for transforming XML documents into other XML documents, or other formats such as HTML for web pages, plain text or XSL Formatting Objects, which may subsequently be converted to other formats, such as PDF, PostScript and PNG. Support for JSON and plain-text transformation was added in later updates to the XSLT 1.0 specification.
In computing, the Java API for XML Processing, or JAXP, one of the Java XML Application programming interfaces, provides the capability of validating and parsing XML documents. It has three basic parsing interfaces:
DocBook is a semantic markup language for technical documentation. It was originally intended for writing technical documents related to computer hardware and software, but it can be used for any other sort of documentation.
Mathematical Markup Language (MathML) is a mathematical markup language, an application of XML for describing mathematical notations and capturing both its structure and content, and is one of a number of mathematical markup languages. Its aim is to natively integrate mathematical formulae into World Wide Web pages and other documents. It is part of HTML5 and standardised by ISO/IEC since 2015.
XSL-FO is a markup language for XML document formatting that is most often used to generate PDF files. XSL-FO is part of XSL, a set of W3C technologies designed for the transformation and formatting of XML data. The other parts of XSL are XSLT and XPath. Version 1.1 of XSL-FO was published in 2006.
An XML editor is a markup language editor with added functionality to facilitate the editing of XML. This can be done using a plain text editor, with all the code visible, but XML editors have added facilities like tag completion and menus and buttons for tasks that are common in XML editing, based on data supplied with document type definition (DTD) or the XML tree.
eXist-db is an open source software project for NoSQL databases built on XML technology. It is classified as both a NoSQL document-oriented database system and a native XML database. Unlike most relational database management systems (RDBMS) and NoSQL databases, eXist-db provides XQuery and XSLT as its query and application programming languages.
GRDDL is a markup format for Gleaning Resource Descriptions from Dialects of Languages. It is a W3C Recommendation, and enables users to obtain RDF triples out of XML documents, including XHTML. The GRDDL specification shows examples using XSLT, however it was intended to be abstract enough to allow for other implementations as well. It became a Recommendation on September 11, 2007.
The identity transform is a data transformation that copies the source data into the destination data without change.
The Oxygen XML Editor is a multi-platform XML editor, XSLT/XQuery debugger and profiler with Unicode support. It is a Java application so it can run in Windows, Mac OS X, and Linux. It also has a version that can run as an Eclipse plugin.
The DocBook XSL stylesheets are a set of XSLT stylesheets for the XML-based DocBook language.
Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages which mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated.
XHTML+RDFa is an extended version of the XHTML markup language for supporting RDF through a collection of attributes and processing rules in the form of well-formed XML documents. XHTML+RDFa is one of the techniques used to develop Semantic Web content by embedding rich semantic markup. Version 1.1 of the language is a superset of XHTML 1.1, integrating the attributes according to RDFa Core 1.1. In other words, it is an RDFa support through XHTML Modularization.
A processing instruction (PI) is an SGML and XML node type, which may occur anywhere in a document, intended to carry instructions to the application.
An XML transformation language is a programming language designed specifically to transform an input XML document into an output document which satisfies some specific goal.
Antenna House Formatter is a proprietary software program that uses either XSL-FO or Cascading Style Sheets (CSS) to convert XML and HTML documents into PDF, SVG, PostScript, XPS, text, and Microsoft Word formats. It supports 30 scripts and over 80 languages.
