Sgml cdata

The term CDATA , meaning character data, is used for distinct, but relate purposes in the markup languages SGML and XML. The term indicates that a certain portion of the document is general character data , rather than non-character data or character data with a more specific, limited structure. CDATA may appear a status keyword in a marked section declaration: ! When used in the declared value of an attribute CDATA refers to the actual value of the attribute (character data), not to the context in which it is parsed. On the other han when parsing elements we need a distinction between character-data-with-no-markup ( CDATA ) and parsed-character-data-where-delimiters-are expected (PCDATA). Difference between PCDATA and CDATA in DTD.

The Standard Generalized Markup Language , or SGML , is a technology that provides a framework for providing this extra layer of information in your files, so that you can maximize both the value of your electronic documents and your ability to manage and access them. HTML (Hypertext Markup Language) is a way of marking up text and graphics so that the most popular web browsers can interpret them. Parsed Character Data ( PCDATA) is a data definition that originated in Standard Generalized Markup Language ( SGML ), and is used also in Extensible Markup Language (XML) Document Type Definition (DTD) to designate mixed content XML elements. In XML, a CDATA section is a formal construct and is the only kind of marked section that is inherited from SGML. It is only relevant and valid in XHTML.

Replaceable character data is like CDATA except that entity references and character references are recognized (Goldfarb, the SGML Handbook). It follows that the replacement of entity references in attribute value literals do not depend on the declared value of the attribute. A CDATA section has been added around the content of the listing, which used to have CDATA declared content.

The indexterm now uses XML empty-tag syntax. Note, however, that this element is no longer empty in the traditional SGML sense, it merely has no content. A document type definition (DTD) is a set of markup declarations that define a document type for a SGML -family markup language (GML, SGML , XML, HTML).

A DTD defines the valid building blocks of an XML document. It defines the document structure with a list of validated elements and attributes. SGML provides an abstract syntax that can be realized in many different concrete syntaxes. Set Theory is a branch of Mathematics to which grade-school students were expose at least in the days of New Math.

The child content of the style element is modelled as SGML CDATA declared content, meaning that any markup delimiters are ignored (up to the sequence of terminating characters as discussed in Script data) Note that legacy HTML also might assume CDATA semantics with xmp, noembe and noframes content. In SGML terms, this means that when these attributes are use the content of the tag is taken to be the same as the content of the tag pointed to by the attribute. If you have used these attributes, your instance will contain both empty and non-empty versions of these tags. SGML , on the other han is an international standard that describes how markup languages are defined.

SGML does not consist of particular tags or the rules for their usage. HTML is an example of a markup language defined in SGML. SGML (Standard Generalized Markup Language) is the standard for encoding paper documents into an electronic format. With the evolution of the internet, it became clear that HTML is no longer able to provide the need for more dynamic content as it has reached its limitations. Representation) Specify the representation of cdata elements.

Supported are atom (default), and string. Strings are allocated on the Prolog stacks and subject to normal stack garbage collection. They are quicker to create and avoid memory fragmentation. SgmlReader - Convert (almost) any HTML to valid XML. A command line utility is also provided which outputs the well formed XML result.

SGML -based content models use the term CDATA (character data) to indicate to processing software that data allowed in certain places will never contain markup and therefore does not have to be parsed in order to be validated. An SGML attribute is a category of information associated with a particular type of element, but not contained within it. Attributes are associated with particular element occurrences by including their name and value within the start-tag for the element concerned. Another type of content model allowing plain text contents is CDATA.

In XML, the element content model may not implicitly be set to CDATA , but in SGML , it means that markup and entity references are ignored in the contents of the element. In attributes of CDATA type however, entity references are replaced. SGML : SDATA Entities in CDATA attribute value literals. It leaves out the ability of XML document authors to.

CDATA sections are useless in HTML browsers, so you hide the CDATA markers within an SGML comment.