11 October Building a Web Site
Current Event Jeremy Thomas
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The Internet What is it? World Wide Web The infrastructure that connects identified computers Links = the wires Routers = the boxes that connect them World Wide Web Subset of the identified computers that contain information to be shared Servers
How Do You Get to the Servers? Computers are connected through a network Network requires protocol to work Definitions of protocol a code prescribing strict adherence to correct etiquette and precedence a set of conventions governing the treatment and especially the formatting of data in an electronic communications system a detailed plan of a scientific or medical experiment, treatment, or procedure The one that is used here is called IP (Internet Protocol)
How Networking Works How do you pass a note to someone? Need to know Who it is going to Which way to pass it Computers need the same thing Who identified by IP address Command Prompt Routers know how to get there But IP addresses aren’t user friendly Give names instead Domain Name Server does the mapping
Anatomy of a URL Protocol: server-name/file-to-display Protocol: usually http Have you ever seen others? shttp? Server-name The computer’s name Usually begins with www Usually ends with 3 characters that define the kind of site However, there are no rules: as long as its registered, you can get there File-to-display Can be a whole path (just like Windows)
How to Build that File Text file that says what to display Web pages use HTML Hypertext Markup Language Two types of information Text Instructions on how to display Instructions are in the form of tags < command >
Why Should You Learn About HTML? HTML editors hide most of the detail But Sometimes you can’t figure out how to make it do what you want Sometimes you just want to make some minor changes to an existing page If you understand how it works, YOU are in control and not the editor
How does Find Work? Tags and text are all ASCII characters Question: Will Find find words that are tags? What kind of algorithm would that require?
General Structure: HTML Page <! --- most important item in head is the title --- > <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="content-type"> <title></title> </head> <! --- body is where the “good stuff” is --- > <body> <br> </body> </html>
Let’s Build a Page How to get started Open Mozilla Window->Composer Note tabs on the bottom of the page
What do you notice?
What do you notice? Matching tags <x> … </x> Non-matching tags Why are there both? Tags can have additional information associated with them Blanks don’t matter
Special symbols < and > are special symbols with special meanings How would you print A < B ? Suggestions?
Special symbols < and > are special symbols with special meanings How would you print A < B ? Suggestions? < for < and > for > & is an escape symbol, which means that it is handled specially Means that you need a special way to display “&” too: &
Colors in HTML What are the three primary colors? HTML uses an RGB (Red-Green-Blue) definition Values are 0-255. Why? (0,0,0) and (255,255,255) represent black and white. Which is which? (0,0,0) = black; (255,255,255) = white
How to indicate colors There are a set of predefined colors that you can use Or you can write them out as rgb (200, 130, 125) Or you can use the following notation #ABCDEF What do you think it means?
Fundamental Page Elements Within <head> <title> -- what will appear at the top of the window Within <body> Attributes on <body> Background color or picture Colors for links
Formatting Text attributes Color Font Size Headings Tables and lists