document markup languages
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Document Markup Languages
Abdallah A Hassan
Agenda
What are Markup Languages? HTML SGML XML Document Type Definition (DTD) MathML Cascading Style Sheets Conclusions
What are markup languages?
Contents of a document (text sections /equations/figures/tables/etc.)
are marked up with tags to both ▪ identify it.▪ delimit it.
So the Document is composed of elements
each element is usually composed of Start tag (usually a word in angle brackets) Data contained in the tag End tag
What are markup languages?
Marking contents of the document with tags can be useful for several reasons: Presentation of document. Making the structure clear. Describing the content. Instructing the tools handling the
document.
Unmarked document example
September 1, 2000
Dear Prof. Stein,
I would like to tell you how much I enjoyed reading your new text
“Digital Signal Processing, A Computer Science Perspective”.
I hope we will be able to meet at the next conference.
Sincerely, Dee Espy
Structural Markup<HEADING>September 1, 2000</HEADING>
<GREETING>Dear Prof. Stein, </GREETING>
<BODY>I would like to tell you how much I enjoyed reading your new
text“Digital Signal Processing, A Computer Science
Perspective”.I hope we will be able to meet at the next conference.</BODY>
<SIGNATURE>Sincerely, Dee Espy</SIGNATURE>
Presentational Markup<RIGHT-JUSTIFY>September 1, 2000</RIGHT-JUSTIFY>
<BOLD>Dear Prof. Stein,</BOLD>
I would like to tell you how much I enjoyed reading your new text
<UNDERLINE>“Digital Signal Processing, A Computer Science
Perspective”.</UNDERLINE>I hope we will be able to meet at the next<BLINK>conference.</BLINK>
Sincerely, <IMAGE SRC=“deesignature.jpg” ALIGN=“left”><FONT FACE=“Times-Roman”>Dee Espy</FONT>
Descriptive Markup<DATE>September 1, 2000</DATE>
Dear <PERSON>Prof. Stein,</PERSON>
I would like to tell you how much I enjoyed reading your new text
<BOOK> “Digital Signal Processing, A Computer Science
Perspective”.</BOOK>I hope we will be able to meet at the next
<EVENT>conference.</EVENT>
Sincerely, <PERSON>Dee Espy</PERSON>
HTML
The language for web browsing. Fixed set of around 100 tags. Focuses on document representation
rather than the meaning of its elements.
HTML
<HTML><HEAD>
<TITLE>Web page title</TITLE>/<HEAD><BODY>
marked-up text
/<BODY></HTML>
Some HTML tags<H1>Level 1 Heading</H1> Level 1 Heading<H2>Level 2 Heading</H2> Level 2 Heading<H3>Level 3 Heading</H3> Level 3 Heading<EM> emphasized </EM> emphasized<P> Paragraph </P> Paragraph<A HREF=url>link</A> link
<UL> <LI> item 1 </LI> .item 1
<LI> item 2 </LI> . item 2</UL>
<OL> <LI> item 1 </LI> 1 item 1
<LI> item 2 </LI> 2 item 2</OL>
SGML (Standard Generalized Markup Language)
HTML was an instance of SGML. Appeared in 70s and became an ISO
standard in 1986. Has not been widely used due to
Complexity Inflexibility
XML (Extensible Markup Language) Widely used for communicating data
between applications. Aimed at simplifying SGML. Flexible and extensible. XML tags focus on the meaning
rather than the representation. An XML document has a hierarchical
structure with a single root element enclosing all other elements.
XML example<Assessment>
<MCQ><question> Algorithm X is : </question><choices><choice> O(n) </choice><choice> O(nlogn) </choice><choice> O(1) </choice><choices><targeted_sections> 2 </targeted_sections> <targeted_sections> 3 </targeted_sections> <ans> 1 </ans></MCQ><MCQ>...</MCQ><Essay> .... </Essay>
</Assessment>
XML (Extensible Markup Language)
Easy to create special purpose languages based on XML DTD (Document Type Definition) Schema
DTD (Document Type Definition) Formal description of the XML
document.
Specifies which elements are allowed and hierarchal structure of elements.
DTD (Document Type Definition) Writing a DTD file for documents of a
specific domain (chemistry, music, etc.)
EQUALS Defining an XML-based markup language for that domain.
DTD example
<!ELEMENT Assessment((MCQ | Essay)+)
<!ELEMENT MCQ(question, choices, hint?, targeted_sections*,ans)>
<!ELEMENT choices(choice, choice ,choice+)>
<!ELEMENT question (#PCDATA)><!ELEMENT hint (#PCDATA)><!ELEMENT targeted_sections (#PCDATA)><!ELEMENT choice (#PCDATA)>...
XML example<?xml version=“1.0“?><!DOCTYPE assessment SYSTEM “http://www.abc.com/assess.dtd“><Assessment>
<MCQ><question> Algorithm X is : </question><choices><choice> O(n) </choice><choice> O(nlogn) </choice><choice> O(1) </choice><choices><targeted_sections> 2 </targeted_sections> <targeted_sections> 3 </targeted_sections> <ans> 1 </ans></MCQ><MCQ>...</MCQ><Essay> .... </Essay>
</Assessment>
Available XML based languages
VML = Vector (graphics) Markup Language SSML = Speech Synthesis Markup Language CPML = Call Policy Markup Language DSML = Directory Services Markup Language MathML = Mathematical Markup Language CML = Chemical Markup Language AML = Astronomical Markup Language BSML = Bioinformatic Sequence Markup
Language GedML = Genealogical Data Markup Language FinXML = Financial market Markup Language ChessML SDML = Signed Document Markup Language RELML = Real Estate Listing Markup Language etc. etc. etc. ...
MathML
Extended from XML to describe mathematical notations.
Recommended by W3C math working group.
Deals not only with presentation but also meaning of formulae components.
MathML
Composed of two parts Presentation MathML Content MathML
Presentation MathML
Focuses on display of an equation Has about 30 elements and 50 attributes ax^2 + bx + c<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE math PUBLIC "-//W3C//DTD MathML 2.0//EN" "http://www.w3.org/Math/DTD/mathml2/mathml2.dtd"> <mrow> <mi>a</mi> <mo>⁢<!-- ⁢ --></mo> <msup> <mi>x</mi> <mn>2</mn> </msup> <mo>+</mo> <mi>b</mi> <mo>⁢<!-- ⁢ --></mo> <mi>x</mi> <mo>+</mo> <mi>c</mi> </mrow>
Content MathML
focuses on the semantic meaning of the expression
<apply> element represents a function or operator, given in the first child
Content MathML ax^2 + bx + c
<math ><apply >
< plus >/< apply >< times >/
< ci>a</ci >< apply>
< power>/< ci>x</ci >
< cn>2</cn >/< apply >/< apply >< apply >< times >/
< ci>b</ci >< ci>x</ci>
/< apply >< ci>c</ci >
/<apply >/<math >
Cascading Style Sheets CSS Language for presentation of
documents written in a markup language.
So, it enables separation of document content from document presentation.
Cascading Style Sheets CSS Benefits:
Improves content accessibility. Enable multiple pages to share
formatting. Page can display differently for different
screen sizes. Page can presented differently for
different rendering methods (on screen , in print, Braille-based devices, etc.)
Cascading Style Sheets CSS Simple syntax English keywords for various style
properties A style sheet is a list of rules Rule : Selector(s) + declaration block Declaration : property : value
h1 { color: black; background-color: red; } h2 { color: white; background-color: green; }
Conclusions Document markup languages allow
applications to handle documents more efficiently.
XML is widely used and core standard for web
It is easy to define a markup language based on XML and customized to documents of a specific domain.
Separation of the document presentation and document content is highly desirable.
Thank you so much
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