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This session delves into the fundamental aspects of the web, covering HTTP, URLs, and HTML. Learn to create web content and understand the layers of the web. Gain insights on editing HTML files, adding style with CSS, and embedding content through JavaScript. Explore the importance of raw text versus WYSiWYG markup for display and semantics. Dive into the world of HTML5 and prepare for the next class on Attention Economics. Engage with the evolution of information technology in the context of business and society.
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Information technology in business and society Session 7 – the Web Sean J. taylor
Administrativia • Assignment 1 due tonight at 1am. • My office hours: moved to 3:30-5:30pm on FRIDAY (permanently?) • Assignment 2 due 2/23 • Blog tips
Blog tips • Use Markdown: • Include “!m” somewhere in the email. • Links are then [Link name](http://linklocation.com) • Use raw links and plain text: • This is my cool link: http://www.google.com • Don’t include dashes before your signature: • Bad: --SJT Good: SJT
Learning objectives • Understand how the web works at a high level. • HTTP • URLs • HTML • Be ableto create your own web page.
Web History • use hypertext • "... to link and access information of various kinds as a web of nodes in which the user can browse at will” • - Berners-Lee and Cailliau • November, 1990
World wide web • web of hypertext documents • viewed by browsers • using a client–server architecture • HTTP: communication protocol • URLs: addressability • HTML: hypertext!
HTTP In action Request Response metadata
HTTP Methods • GET – retrieve a resource • POST – create a new resource • PUT – update an existing resource • DELETE – delete a resource • Always include a URL!
Uniform resource locators • Format: • scheme://hostname:port/path?query_string#fragment_id • Scheme: http, https, ftp, gopher, wais • Domain: Hostname is usually subdomain.domain.tld • Port: Each server can have multiple ports • Path: + query string: define a resource • Fragment: used for web page navigation
Basic Document Structure • <html> • <head> • <title>My Awesome Webpage</title> • </head> • <body> • <h1>This is the heading!</h1> • <p>It was the best of webpages.</p> • <a href=“http://google.com”>Google</a> • </body> • </html>
More Tags • <ul> • <li>List item 1</li> • <li>List item 2</li> • </ul> • <h1>Big header!</h1> • <h2>Smaller header</h2> • <imgsrc=“http://link.to/image.png”></img> • <div>Some content</div> • <span>Some content</span>
Adding Style with CSS • <style> • h1 { color: blue; text-align: center; } • P { width: 400px } • </style> • Or put a link in your <head> area. • <link rel=“stylesheet” type=“text/css” href=“style.css”></link>
Programmability with JS • De-facto programming language for the web. • Tons of resources for learning. • Makes a webpage dynamic.
Markup:Display or Semantic • Some HTML tags are intended to convey semantics. • This allows machines to understand web pages better but giving them an idea of what information is placed where in the document. • “I have a dream for the Web [in which computers] become capable of analyzing all the data on the Web – the content, links, and transactions between people and computers. “ • -- Tim Berners-Lee • Challenges? Benefits?
“Dive into HTML5” Mark Pilgrim Web Book
Next Class:Attention Economics • The Information Diet (Chapter 3)