HTML & CSS Workshop Notes

Sponsored by Upsilon Pi Epsilon The Computer Science Honors Society

Upsilon Pi Epsilon

UPE is the Computer Science Honors Society.

It is a national honors society, with over 120 University Chapters around the country.

“New” to USC

Workshop series around web 2.0 technologies

This is the first of many

Future topics will include: Javascript, PHP, Ruby on Rails, and more.

Send us your ideas!

What is Web 2.0?

“Web 2.0, a phrase coined by O'Reilly Media in 2004, refers to a supposed second-generation of Internet-based services — such as social networking sites, wikis, communication tools, and folksonomies — that let people collaborate and share information online in previously unavailable ways.”

- Wikipedia (a Web 2.0 organization)

Why should I care?

What We’ll Cover Today

HTML (Hypertext Markup Language)

DOM (Document Object Model - briefly)

CSS (Cascading Style Sheets)

HTML

History of HTML

Tim Berners-Lee created first HTML version in the late 1980s (as a subset of SGML)

Needed a simple way to share research among colleagues; piggy backed off newly evolving Internet (previously just text)

HTML spread as multiple proprietary versions; in 1993 the IETF published a working draft of the first “official” HTML

History of HTML Part 2

Simplicity made things easy for people new to computers and publishing

Also left the “code” a mess, leaving every browser to handle different mistakes in its own way

Soon, the World Wide Web Consortium (W3C) was created to draft a set of standards for all web browsers to adhere to

Features were added to HTML very quickly: tables, colors, backgrounds, fonts, etc.

Web sites started becoming very complex

It became impossible to manage all the HTML tags needed to style the content on multiple sites, code bases starting becoming huge, tables were being used to make better designs... things got ugly.

We needed a solution to this problem, and that solution was CSS.

With the revolution of Cascading Style Sheets, HTML (and later XHTML) became about describing content, not presentation

The look of a web page (the presentation) was left entirely to style sheets, which could be common to entire sites

Setting up a web “Presence”

No point to a website if no one else can see it...

USC lets every student create a web presence on the aludra.usc.edu server

If you don't have it setup yet:

telnet aludra.usc.edu

type requestwww

follow the instructions

Setup Part 2

To see your web presence, point browser to http://www-scf.usc.edu/~username

To upload files to your web account, use an FTP client

You can download COREFTP(PC) or Fetch(Mac) from usc.edu/software or poke around your PC for an app with "FTP" in title

Login to aludra.usc.edu with usual USCWeb login

Upload files to public_html folder

HTML: What is it?

HTML stands for Hyper Text Markup Language

An HTML file is a text file containing small markup tags

The markup tags tell the Web browser how to display the page

An HTML file can be created using a simple text editor or a WYSIWIG editor

Hello World! <html> <head> <title>Hello World!</title> </head> <body> Hello World! </body> </html>

HTML Basics: Tags/Attributes Tags/Attributes

HTML tags are used to mark-up HTML elements

Tags are surrounded by the two characters < and >, which are called angle brackets

Tags normally come in pairs like <b> and </b>. The text between the start and end tags is the element content

Tags are not case sensitive, <b> means the same as <B>, but use lowercase: you’ll find out its better

Tags often have attributes, which gives the browser additional information about displaying the element

Attributes come in name-value pairs, with the value in double or single quotes (e.g. <img width=”100px”>)

HTML Basics: Formatting Tags Formatting Tags

In HTML, formatting is not based on whitespace! (example)

Use tags to format text:

<p></p> - paragraph tag, optional align attribute

<br> - line break tag

<b></b> or <strong></strong> - boldface tag, <strong> is more standards-compliant now

<i></i> or <em></em> - italics tag, <em> is more standards-compliant now

<ul><li>blabla 1</li> .. </ul> - unordered list tag, creates bulleted list, can be nested

<ol><li>blabla 1</li> .. </ol> - ordered list tag, creates numbered list, can be nested

HTML Basics: Hyperlinks & Images Hyperlinks & Images

Anchor tag can be used to create hyperlink or define an anchor within a page

<a href=" http://www.google.com ">google</a> - creates hyperlink, optional target, title attributes, URL can be relative or absolute

<a name="section2"></a> - creates anchor in page

<a href="index.html#section2">section2</a> - to link to in-page anchor

<img src="URL.gif"> - creates image, optional width/height attributes, alt attribute to provide alternate text, align attribute to specify around-text wrapping, border attribute

Image tags can be nested in hyperlink tags to create hyperlinked images

HTML Basics: Tables/Frames

Both of these are considered evil nowadays.

Before <DIVS> were introduced, people used tables to layout websites (e.g. multi-column website)

The HTML for tables is obtuse and prone to corruptibility (just try looking at the source of a fully tabled website)

But it exists...and could be occasionally useful

<table></table> - creates table, optional width/height/align/bgcolor attributes

<tr></tr> - creates table row with the same attribute options

<td></td> - creates table cell with the same attribute options

Frames: web-designers used to use frames to separate the navigation page from the site's content (e.g. all CS websites!)

Frames are generally a bad idea... http://www.karlcore.com/articles/article.php?id=2 So we won't tell you tags for them.

HTML Basics: Forms

Very common on the web as they provide interactivity

<form></form> - defines form, optional method/name/action attributes to tell browser where to send results when submit pressed

<input></input> - generic input tag, used always with type attribute to specify type (checkbox, radio, text, submit), also optional name/value attributes

<textarea></textarea> - multi-line text area input, optional rows/cols attributes

<select> <option>op1</option> ... </select> - creates combo/dropdown box

HTML Basics: Colors

HTML Basics: Color

Color is used extensively in HTML: text color, background color, border color, link color, hr color, etc

Only 16 color names are approved by W3C - aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, and yellow

All other colors should be referred to by Hexadecimal codes (#RRGGBB)

Always pick a pleasing color scheme for your site

Color references: http://w3schools.com/html/html_colors.asp http://www.degraeve.com/color-palette/ http://wellstyled.com/tools/colorscheme2/index-en.html http://wellstyled.com/tools/colorscheme2/index-en.html http://www.siteprocentral.com/cgi-bin/feed/feed.cgi

HTML Basics: References

http://w3schools.com/html/default.asp

http://w3schools.com/html/html_quick.asp

http://webmonkey.com/webmonkey/reference/html_cheatsheet/

http://www.htmlcodetutorial.com /

http://validator.w3.org /

Standards

Read the W3C Specs! Search them!

Use the W3C Validator!

Write valid XHTML Strict/Transitional (or HTML 4.1) whenever possible (always!)

Separate content and presentation: use style sheets to change the look of your site!

Document Object Model

A graph representation of the structure of an HTML/XHTML document

An API for accessing and interacting with the graph and its elements

The key ingredient to DHTML, AJAX, and this whole Web 2.0 thing

Visualizer: http://www.aharef.info/static/htmlgraph/

CSS

Cascading Style Sheets

A standard method of applying style and appearance information to text and other elements of a web page

Cascading means that properties “cascade” down through all child elements of a given element

Selectors

Style sheets are made up of individual style elements that define size, color, fonts, etc.

Each style has a unique name: a selector

Selectors refer to specific elements, or sets of elements, in your (X)HTML files

Pseudo Selectors

pseudo selectors can select specific parts of an element, or elements with specific properties

allows us to create :hover effects

Syntax

C style syntax

almost never need the @media type declaration, but it is very useful to know - can target different types of devices easily

adding a background color to the body:

body {

background: red;

}

Style Sheets

To style a webpage, you need lots of individual selectors and styles

Create style sheets to contain all of these style definitions

add them to your page a number of ways:

<link rel=stylesheet href="whatever.css" type="text/css">

<style type=”text/css”> @import: url(aStyle.css) </style>

or declare styles right in the style tag

CSS Layout

There are two types of elements in the CSS world: box level elements, and inline elements

tags that would normally cause a newline in html are generally block level elements

<div> is the empty box element

text it usually inline content

<span> is the empty inline element

Any element can be told to be a box

CSS Positioning

There are a few different ways to position box elements:

position

absolute

fixed

relative

float - most people are confused by this!

left

right

Box Model

CSS Properties http://www.ilovejackdaniels.com/css_cheat_sheet.pdf

Demo

Considerations

CSS does not behave as expected if your (X)HTML is not well formed: VALIDATE!

There are more tags that you will ever memorize, so look things up with google

CSS is complex - go home, read about it online, try things out. The best way to learn is probably to look at existing web pages CSS and see what does what