CSCI E-153, Web Development Using XML
About CSCI E-153
Course Web Site:
http://cscie153.dce.harvard.edu/
CSCI E-153 Web Development Using XML (12151)
CSCI E-153
Web Development Using XML(12151)
David P. Heitmeyer, AM, Senior Software Product Architect/Engineer, iCommons, Central Administration Information Technology, Harvard University.
Fall term:
Tuesdays, Sept. 16, 5:30-7:30 pm, Harvard Hall, Room 104. Optional sections to be arranged.
Online and on-campus options. See Distance Education.
Students learn key XML technologies (XML, XPath, XSL, XSL-FO, XML Schema, RNG, DTD, XQuery, DOM) as well as specific markup languages relevant to website development (XHTML, XHTMI Mobile Profile, RSS,
RDF, XSL-FO, SVG, DocBook, OOXML, OpenDocument, XForms). In addition, the course covers topics such as XML and databases (native XML databases and RDBMS), XML programming APIs (DOM and SAX), Apache
Cocoon (an open-source XML publishing framework), and the role of XML in Web 2.0 to deliver data and functionality through Ajax and web services (SOAP and REST). Using these technologies, students
develop dynamic, data-driven websites that are capable of delivering content in a variety of media formats (screen, text, print, graphics) to a variety of devices (desktop, handheld, mobile) for a
variety of audiences. Prerequisite: CSCI E-12, or the equivalent experience. (4 credits)
Syllabus: Books
In addition to the texts for the course, there will be suggested readings of online material.
Required: XML in a Nutshell, 3rd edition
XML in a Nutshell
| Harold, Elliotte Rusty and W. Scott Means. 2004.
XML in a Nutshell, 3rd Edition. O'Reilly & Associates. 689 p. ISBN
0596007647.
This is another excellent
Nutshell book from O'Reilly. It provides good, solid, readable information
about the key XML technologies you need to know. |
Required: XSLT 2.0, 3rd edition or XSLT 2.0 and XPath 2.0, 4th edition
XSLT 2.0 and XPath 2.0, 4th edition
| Kay, Michael. 2008
XSLT 2.0 and XPath 2.0, 4th edition. Wiley Publishing, Inc. 1316p. ISBN 0470192747. This is an excellent book that provides excellent coverage and reference for XSLT and XPath. This is essentially the XSLT 2.0, 3rd ed and XPath 2.0, 3rd ed books combined. |
XSLT 2.0
| Kay, Michael. 2004
XSLT 2.0, 3rd edition. Wiley Publishing, Inc. 911p. ISBN 0764569090. This is an excellent book that provides excellent coverage and reference for XSLT, versions 1 and 2. |
Recommended: XPath 2.0
XPath 2.0
| Kay, Michael. 2004
XPath 2.0. Wiley Publishing, Inc. 530p. ISBN 0764569104. This is the companion book for XSLT 2.0, 3rd edition. This is optional, and is certainly not needed if you have "XSLT 2.0 and XPath 2.0, 4th edition". |
Required and recommended texts are available through:
Syllabus: Prerequisites
XML experience. No prior experience with XML will be assumed.
Web experience. It will be expected that students already have an understanding of the web and have taken
CSCIE-12
(Fundamentals of
Web Site Development), or CSCI S-H,
or have equivalent experience. Students should have a solid understanding of Hypertext
Markup Language (HTML) and a familiarity with Cascading Style Sheets
(CSS).
Programming experience. Experience with any programming language will suffice (Pascal,
Basic, Lisp, C/C++, C#, Perl, Python, Java, etc.)
Computing Environment. It is expected that students will be able to install, configure, and run certain software in their own computing environment, namely Cocoon, Maven, and Subversion. Cocoon is a Java-based XML publishing framework, which can be installed and run with the utility Maven. In addition, Subversion, a widely-used revision control system, will be used to submit assignments. While guidance on getting these tools to work on other systems will be provided, it is expected that students will be capable of setting up their computing environment. Although a course server will be provided for students to work on, students are encouraged to use their own environments for reasons of control, learning, and performance. In addition the use of Amazon's Elastic Computing Cloud (EC2) will be demonstrated to provide low-cost, flexible, and dedicated computing environments for course work. Use of EC2 is not required, and any usage charges will be the responsibility of the student. Assignment 1 is geared towards getting the environment established.
Syllabus: Requirements
| Description | Points |
|---|
Assignments. There will be 5 assignments over
the course of the term (50,150 points each).
- Assignment 1. Getting Started and XML Basics. (50 pts)
- Assignment 2. XSLT and XPath, Part 1; Getting Started with Cocoon. (150 pts)
- Assignment 3. XSLT and XPath, Part 2. (150 pts)
- Assignment 4. XML content formats: XML and print (XSL-FO), Mobile Devices, Office. (150 pts)
- Assignment 5. XML and Web 2.0. (150 pts)
| 650 points |
Community Participation.
This component is focused on participation in the course community (online as well as in-person).
There will be specific opportunities throughout the term for points in this area, such as:
- Short responses to blog posts by instructors
- Contributing information to a Google map of the class participants.
- Making contributions to CSCI E-153 "Delicious" bookmark collection.
- Blog entries about uses of XML in your professional or personal areas of interest.
| 100 points (maximum) |
| Final Project The final project will consist of an XML-driven Course Catalog Website
with a variety of media-type outputs (XHTML, HTML, XHTML Mobile
Profile, PDF). A component of the final project will include an optional presentation at the last class meeting.
Students will have an option to collaborate in self-formed groups (3 to 4 students) or to work independently for the final project. Additional details regarding the Final Project will be provided in class. | 300 points |
| Total Points Possible: | 1050 points |
Late Assignments
Late assignments will be not accepted and a score of zero will be recorded for any assignment that is not submitted on time.
Each student will have 4 tokens that may be used to extend the due
date of an assignment or assignments. One token will extend the due
date by one day. You may use more than one token on an assignment. Each
student can use at maximum four tokens (they can't be traded, shared,
given away, and have no cash value). Tokens cannot be used on the Final
Project.
Use of tokens will be indicated when assignment is submitted.
Academic Honesty and Student Responsibilities
Welcome to CSCI E-153
Harvard Hall, Harvard University, Cambridge, Massachusetts
View Larger Map
Students
XML: Extensible Markup Language
Happy 10th Birthday to XML!
"There is essentially no computer in the world, desk-top, hand-held, or back-room, that doesn't process XML sometimes..."
Tim Bray, read more from the press release.
- self-describing data
- interoperable (languages, platforms, applications)
- content and data
- machine-readable
- presentation and display for people
Address Book Example
Data
Contacts in and Address Book in XML:
Presentation
XHTML for presentation:
Displayed in a browser:
XML in 10 Points
- XML is for structuring data
- XML looks a bit like HTML
- XML is text, but isn't meant to be read
- XML is verbose by design
- XML is a family of technologies
- XML is new, but not that new
- XML leads HTML to XHTML
- XML is modular
- XML is the basis for RDF and the Semantic Web
- XML is license-free, platform-independent and well-supported
An aside: W3C
The World Wide Web Consortium was created in October 1994 to lead the World
Wide Web to its full potential by developing common protocols that promote its
evolution and ensure its interoperability. W3C has around 450 Member organizations
from all over the world and has earned international recognition for its
contributions to the growth of the Web. (from http://www.w3.org/Consortium/
)
Content and Presentation
Content
XML is all about content.
- XML documents can hold data
- XML documents can hold narratives/prose
Presentation
XML is all about presenting your content.
- XHTML / HTML
- PDF
- Graphics
- WML
- Text
- RTF
- Office/Word/Excel
Demonstration of the Power of XML and XSLT
XSLT - Extensible Stylesheet Language for Transformation
Aggregation, Re-mixing, Mashups
XML is often at the center of data "aggregation," "mashups," and "re-mixing" that is
characteristic of some "Web 2.0" sites and applications.
Weather
National Weather Service
Major League Baseball
How they were made
- Programmatic Interface to construct XML from non-XML source (SAX or DOM)
JSON Data for August 1, 2008 from mlb.com - Transformation to XML "Chart format" (XSLT)
- Transformation to Scalable Vector Graphic (SVG, by XSLT)
- Serialization of SVG to PNG image format
baseball.xml snippet:
Election 2004: Massachusetts in Red, Blue, and Purple
Red = Bush
Blue = Kerry
Select a thumbnail to view a larger image
Massachusetts Cities and Towns | |
Red/Blue Map | 
Purple Map |
How they were made
- GIS data (non-XML) from MassGIS
- XML Document Object Model (DOM)
- Scalable Vector Graphics (SVG)
- Vote data from USA Today Web Site (XHTML)
- XSLT and XPath
- SVG to JPEG/PNG Conversion
Google Maps & Google Earth
DHS Threat Level Advisory
Syndication Feeds: RSS, Atom, Podcasts
RSS and Atom are lightweight XML formats for sharing headlines and other Web content.
RSS Snippet: Item
The heart of an RSS feed is an "item", which can have a title, link, and description.
Item from BBC News:
Atom Snippet
Atom feed displayed in Firefox:
Consuming Feeds
- External Application
- Email client
- Web Browser
- Portal (e.g. My Yahoo!)
Subscribe to Feeds via an E-mail client
Firefox "Live Bookmarks"
Firefox
"Live Bookmarks" alert you to the existence of an RSS feed for a site and allow
convenient access to the items in the feed.
CSCI E-153 RSS Feed
RSS Feed of CSCI E-153 Announcements
Podcasts: An Adaptation of RSS
Adapting and extending RSS for use with iTunes, iPods, and other mobile media players.
- Each "item" has an "enclosure," which is a link to the media file (typically
MP3).
- iTunes uses a specific XML module added to RSS (note the itunes
prefix to some elements within the item.
Podcast snippet (
WBUR/NPR On Point
with Tom Ashbrook Podcast):
RSS and Yahoo! Maps
Yahoo! Maps and RSS with GeoInfo
Technologies, Tasks, and Tools
XML-related standards, technologies and tools grouped by
purpose| Authoring and structuring | XML, SGML | Text Editor |
| Defining and Validating | DTD, W3C XML Schema, RELAX NG (RNG), Schematron | XML Parser (Apache Xerces ) |
| Formatting, Styling, Presentation | CSS, XSLT, XSL-FO, DSSSL | XSL-FO Processor (Apache FOP)
XSLT Processor (Apache Xalan, Saxon) |
| Transforming | XSLT | XSLT Stylesheet Processor (Apache Xalan, Saxon
) |
| Navigating and Searching | XPath, XQuery | |
| Specific Document Formats (XML Applications)
| XHTML, DocBook, WML, SVG, MathML, etc. | Text Editor |
| Merging | XML Inclusions (XInclude) | |
| Relating and Associating | RDF, XTM (XML Topic Maps) |
|
| Programming | SAX, DOM | Programming Language (Java, C#, Perl, Python, etc.) |
| Application Server (Publishing / Programming) | XML, XSLT, XPath, SAX, DOM, ... | Apache Cocoon, Apache AxKit |
Class Schedule
SGML and XML
XML: a structure for creating and working with markup languages
XML provides a way to create markup languages. The markup languages are called
applications of XML. Some applications of XML are:
- XHTML (Extensible HyperText Markup Language)
- RSS and Atom
- WML (Wireless Markup Language)
- DocBook
- Open Document Format (ODF)
- Open Office XML
- Office Open XML (OOXML, OpenXML)
- MathML (Mathematics Markup Language)
- SVG (Scalable Vector Graphics)
- P3P (Platform for Privacy Preferences)
- XBEL (XML Bookmark Exchange Language)
- OPML (Outline Processor Markup Language)
- ...and many others...
- ...some general in nature...
- ...some industry-specific...
XML Documents: Well-formed, Valid
- Must: Well-formed
- May: Valid
Well-formed XML Documents
- Must have one and only one root element.
- Elements must be properly nested.
- Attributes must be quoted.
- XML elements are case sensitive.
- End tags are required.
- Empty elements can contain the end marker.
- Attributes cannot be repeated.
- Character
| Entity | Character |
|---|
| < | < |
| > | > |
| & | & |
| " | " |
| ' | ' |
Valid
- Well-formed and
- Conforming to rules of a schema
- Document Type Definition (DTD)
- W3C XML Schema
- RNG (Relax NG)
- Schematron
A Tree
Visualizing a Tree
Tree view using Stylus Studio
Tree view using Amaya Browser/Editor
Tree View generated with XSLT (
XSLT used to make a
Tree View of and XML document.)
Mechanics of an XML Document
XML Declaration
<?xml version="1.0" encoding="UTF-8" ?>
XML version
1.0
Extensible Markup
Language (XML) 1.0 (Fourth Edition), August 2006
XML encoding
You may also see ISO-8859-1 quite a bit (also known as Latin-1).
When in doubt, use UTF-8 (it is the default anyway).
Character Entities
In XML, there are only 5 named character entities defined:
- >
- <
- &
- "
- '
Numeric Character Entities
- Copyright symbol (©)
- codepoint decimal 169.
&169; → © - codepoint hexadecimal 00A9.
© → ©
Use &#nnn; (nnn = decimal number) or
&#xnnnn; (nnnn = hexadecimal number).
Named Entities from XHTML
Named entities (e.g. ©) are defined as part of the markup language.
Named XHTML entities
are not available generally in XML documents.
XML document mechanics and meaning
Whitespace. In general, whitespace does not change the
meaning of XML (as in (X)HTML). Note that there are exceptions to this.
Order of elements is meaningful.
Order of attributes is not meaningful.
Comments. XML comments are just like comments in HTML
CDATA sections
In CDATA sections, do need to have <, >, and & as character entities. Often used to
put 'markup' into an element.
Syntax:
XHTML and MathML
XML Namespaces
- declare the namespace URI
- as the "default" namespace, or
- bind a "prefix" to the namespace URI
- use the namespace prefix
XHTML and MathML
Define prefix and namespace URI binding and default namespace:
Use MathML inline in XHTML document:
XML Namespaces
Parts
- xmlns attribute to bind to URI
- e.g.
xmlns:mml="http://www.w3.org/1998/Math/MathML" - URI for MathML:
http://www.w3.org/1998/Math/MathML
- prefix
- local name
- e.g. math, mtext, mspace, mi, mo, msup
- qualified name, QName, raw name
- e.g. mml:math, mml:mtext, mml:mspace, etc.
- Note that the prefix is bound to the URI namespace, so
"mml:math" might be represented as:
{http://www.w3.org/1998/Math/MathML}math
Purposes
- The URI determines reality.
- The URI must provide uniqueness. It may provide a useful
resource.
- prefix used to map element to namespace URI. Chosen by document author, typically
following a convention.
Setting Default Namespaces
The following documents have the same "meaning":
Snippet XHTML and MathML, with "mml" prefix used for all "MathML" elements. | XHTML and MathML, with MathML defined as default namespace for "math" element and all
children. |
XML Namespaces: Prefix and URI
Need to bind a prefix to a URI.
W3C RSS document
GovTrack.US People RDF Data
- The URI determines reality. The prefix is by convention or
author's choice
- The URI must provide uniqueness. It may provide a useful
resource.
Extensible Stylesheet Language Transformations (XSLT) and XML Path Language (XPath)
XSLT
XPath
Simple XSLT Example as an Introduction
XSLT
XSLT Processors at work
- Server-side
- "offline" build / procesing
- "dynamic" processing at time of request (e.g. Apache Cocoon)
- Client-side
IE 5.5+ and NS 6+ and Mozilla 1+ have XSLT processors
A closer look:
- XML Parser
- XSLT Processor
- Serialize
XSLT Processors
In this course we will be using the XSLT processors Saxon (Michael Kay) and
Apache Xalan (Apache Software Foundation).
XSLT Examples
XSLT Example 1
XSLT Example 2
XSLT Example 3
Default Rules for XSLT Processing
- Document node: apply-templates
- Element nodes: apply-templates
- Text nodes: output text
The simplest XSLT
The result:
Common XSLT elements
xsl:template
define a template to process a node that matches
- Literal Result Elements (LRE)
XSLT Stylesheets are XML documents themselves! - match attribute
- xsl:apply-templates
xsl:apply-templates
select list of nodes to apply templates to
When you think about XSL, think in terms of recursion! Don't loop, recurse!
xsl:value-of
output a value of a selected node or expression
