Join Timothy as he shows you how to process XML with PHP. In this tutorial you will learn the basics of using PHP to interpret XML.
A markup language is a collection of directions and special symbols that are inserted throughout a document. These directions can identify special sections of a document and further define the information's background and meaning.
A commonly used markup language on the Internet today is Hyper Text Markup Language (HTML). HTML directions (which are known as elements) are interspersed throughout a text file that can then be viewed by a web browser program. The elements can affect the formatting of text, break the document up into logical sections such as headers, paragraphs and lists and can even link several documents together.
The eXstensible Markup Language (XML) isn't really a language like HTML. Rather, XML is a subset of rules taken from a larger language known as SGML that lay down guidelines on how new markup languages should be written. Many new and specialized markup languages (called Applications) have cropped up and anyone can use XML to write their own markup language to fit a certain need. Because the Application follows the XML specification, the information within its documents can be easily shared with others and it is easier to write the interpreting programs.
Some examples of popular XML Applications are:
BSML - Bioinformatic Sequence Markup Language CDF - Channel Definition Format CKML - Conceptual Knowledge Markup Language CML - Chemical Markup Language EAD - Encoded Archival Description GedML - Genealogical Data in XML ICE - Information and Content Exchange IMS - Information Metatdata Specification JSML - Java Speech Markup Language MathML - Mathematical Markup Language OFX - Open Financial eXchange OSD - Open Software Description RDF - Resource Description Framework RSS - Really Simple Syndication SMIL - Synchronized Multimedia Integration Language SVG - Scalable Vector Graphics TIM - Telecommunications Interchange Markup UXF- UML eXchange Format XHTML - eXstensible Hypertext Markup Language XML/EDI - XML/Electronica Data Interchange
PHP provides several functions to process XML-compliant documents by using the expat library. These functions are made available to the programmer if PHP has been compiled with expat.
