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WWW Forms and Search. Forms. URL - always fetch a particular page What if the information we want varies from time to time and from user to user?. Forms. Forms - requests to a web-site. How to get information from the user When to send the request Where to send the request
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Forms • URL - always fetch a particular page • What if the information we want varies from time to time and from user to user?
Forms - requests to a web-site • How to get information from the user • When to send the request • Where to send the request • How to send the user’s information with the request
<body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body>
Labels <body> <h1>Example form</h1> <formaction="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body>
How to get info from the user <body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body>
Parts to an input tag • <input name=“N” size=20> • Name - the name that this input information will be given • Size - the number of characters that the user can type
When to send the request <body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body>
Where to send the request <body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body>
How to send the user informationin a URL <body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body> http://icie.cs.byu.edu/cgi/findMe?firstName=Phred&lastName=Phinster
How to send the user informationin a URL <body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body> http://icie.cs.byu.edu/cgi/findMe?firstName=Phred&lastName=Phinster
How to send the user informationin a URL <body> <h1>Example form</h1> <form action="http://icie.cs.byu.edu/cgi/findMe"> First name <input name=firstName size=20 value="Phred"> <p> Last name <input name=lastName size=20 value="Phinster"> <p> <input type="submit" value="Find Me"> </form> </body> http://icie.cs.byu.edu/cgi/findMe?firstName=Phred&lastName=Phinster
Forms - How does the server respond? • Not every URL refers to a page • CGI - Common Gateway Interface • You can give a server a program and place it at a URL. • The server will then run the program and return its result rather than fetch a page
Search • How do we describe the page that we want?
Search • How does Google know where that page is? • Find as many web pages as you can • For each web page prepare a list of words on that page • For each word in all of the web keep a list of pages that have that word
CS 100 - the winner • Why? Both have the words CS 100 • CS 100 in <title> • CS 100 in text
Problems with word searches • Search for “doctor” • What about pages with the word “doctors”? • What about pages with the word “physicians”? • What about pages about “witch doctors”? • What if the page only has a picture of a doctor? • What if the only use of the word doctor is in a picture?
Blocking pornography • The reverse of the search problem • I don’t want pages that have this • How do you describe what you don’t want?
Blocking pornography • Keep a list of all bad sites • If site is on the black list then refuse to make an Internet connection • What if someone creates a new site? • Keep a list of bad words and block any URL or page that has those words • What about “Middlesex, England”? • What about “breast cancer”? • What about slang words? • What about pictures?