History Markup Annotations instructing how the document should appear in print Word processors use different markup schemes SGML IBM - Standard Generalized Markup Language Markup instructions stored with ASCII file Any computer could render document Lilly Example
History HTML Tim Berners-Lee created HTML – subset of SGML Not platform or application specific Only server software needed to publish file s on the net Structure versus content Browser parses HTML file into a tree
History Sample HTML File <FONT SIZE=14 FACE=Swing> <B> Bryan Moore </B><BR> </FONT> <FONT SIZE=12 FACE=Textile> 1234 Sunset Ave . <BR> Walla Walla, WA 12345 <BR> (123)123.4567<BR > </FONT> Web Applications and Real World Design - Knuckles
History Web Applications and Real World Design - Knuckles Browser parse tree
History Problems with extracting data Need to write a computer program to extract the names and addresses by selecting text strings following font tags Content and structure of document become intertwined Not the intention of SGML and original HTML Cascading Style Sheets Attempt to separate content and style
History Parse tree using CSS Web Applications and Real World Design - Knuckles Still need to reference Information based on “second string after BR” Information is not meaningful
History Extensible Markup Language XML Extensible- can create own tags Complete separation of content and style Web Applications and Real World Design - Knuckles
History Releases HTML 4.0 1997 XML 1.0 1998 XML and HTML need to better cooperate XHTML 1.0 2000 XHTML Contains elements and attributes of HTML Elements must have closing tags Lowercase Attributes must have values Attributes in single or double quotes
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- Fall '14