Introduction to Dynamic Web Content

1. Introduction to Dynamic Web Content

2. Internet Request HTTP PHP JavaScript GET SQL HTML Response AJAX Templates Redirect CSS MVC POST Cookies

3. Internet Request HTTP PHP JavaScript GET SQL HTML Response AJAX Templates CSS Redirect MVC POST Cookies

4. What is a Protocol? • A set of rules that all parties follow for so we can predict each other's behavior • And not bump into each other • On two-way roads in USA, drive on the right hand side of the road • On two-way roads in the UK drive on the left hand side of the road

5. HTTP • The HyperText Transport Protocol is the set of rules to allow browsers to retrieve web documents from servers over the Internet

6. HTTP - Hypertext Transport Protocol • The dominant Application Layer Protocol on the Internet • Invented for the Web - to Retrieve HTML, Images, Documents etc • Extended to be data in addition to documents - RSS, Web Services, etc.. • Basic Concept - Make a Connection - Request a document - Retrieve the Document - Close the Connection

7. Getting Data From The Server • Each the user clicks on an anchor tag with an href= value to switch to a new page, the browser makes a connection to the web server and issues a “GET” request - to GET the content of the page at the specified URL • The server returns the HTML document to the Browser which formats and displays the document to the user.

8. Web Server 80 Browser

9. Web Server 80 Browser Click

10. Request Web Server 80 GET http://www.dr-chuck.com/page2.htm Browser Click

11. ....... Request Web Server 80 GET http://www.dr-chuck.com/page2.htm Browser Click

12. ....... Request Response Web Server <h1>The Second Page</h1><p>If you like, you can switch back to the <a href="page1.htm">First Page</a>.</p> 80 GET http://www.dr-chuck.com/page2.htm Browser Click

13. ....... Request Response Web Server <h1>The Second Page</h1><p>If you like, you can switch back to the <a href="page1.htm">First Page</a>.</p> 80 GET http://www.dr-chuck.com/page2.htm Browser Parse/ Render Click

14. Internet Standards • The standards for all of the Internet protocols (inner workings) are developed by an organization • Internet Engineering Task Force (IETF) • www.ietf.org • Standards are called “RFCs” - “Request for Comments” Source: http://tools.ietf.org/html/rfc791

15. http://www.w3.org/Protocols/rfc2616/rfc2616.txt

17. Making an HTTP request • Connect to the server like www.dr-chuck.com • a "hand shake" • Request a document (or the default document) • GET http://www.dr-chuck.com/page1.htm HTTP/1.0 • GET http://www.mlive.com/ann-arbor/ HTTP/1.0 • GET http://www.facebook.comHTTP/1.0

18. Web Server $ telnet www.dr-chuck.com 80 Trying 74.208.28.177... Connected to www.dr-chuck.com.Escape character is '^]'. GET http://www.dr-chuck.com/page1.htm HTTP/1.0 HTTP/1.1 200 OK Date: Thu, 08 Jan 2015 01:57:52 GMT Last-Modified: Sun, 19 Jan 2014 14:25:43 GMT Connection: close Content-Type: text/html <h1>The First Page</h1> <p>If you like, you can switch to the <a href="http://www.dr-chuck.com/page2.htm">Second Page</a>.</p> Connection closed by foreign host. Browser

19. Accurate Hacking in the Movies • Matrix Reloaded • Bourne Ultimatum • Die Hard 4 • ... http://nmap.org/movies.html http://www.youtube.com/watch?v=Zy5_gYu_isg

20. Getting to Know Our Browsers

21. Find Developer Mode • Chrome: View->Developer • FireFox: https://getfirebug.com/ • Safari: Preferences -> Advanced -> Show Develop Menu • IE: ???

22. ....... Request Response Web Server <h1>The Second Page</h1><p>If you like, you can switch back to the <a href="page1.htm">First Page</a>.</p> 80 GET http://www.dr-chuck.com/page2.htm Browser Parse/ Render Click

23. More Detail... • Browser – HTML, CSS, "Document Object Model" (the DOM) and JavaScript • Web Server – Apache(or similar) we server with a PHP extension installed • Database Server running MySQL, Postgress, Oracle, SQL Server or similar

24. Document Object Model <table> <tbody> <tr> <td>Shady Grove</td> <td>Aeolian</td> </tr> <tr> <td>Over the River, Charlie</td> <td>Dorian</td> </tr> </tbody> </tbody> http://www.w3.org/TR/DOM-Level-2-Core/introduction.html

25. Browser Web Server Database Server Time D OM Apache MySql PHP JavaScript

26. Browser Web Server Database Server Time D OM Apache MySql PHP JavaScript

27. Browser Web Server Database Server Time D OM Apache MySql PHP JavaScript http://www.php-intro.com/code/rrc/

28. Our Technologies

29. Early History of Important* Programming Languages • Machine Language (1940's) • Assembly Language (1940's) • FORTRAN - Mathematics expressions (1955) • C - High-productivity Assembly Language (1969)

30. Science Calculations System System C uses curly braces { } for code blocks. Scripting/ Interpreted http://en.wikipedia.org/wiki/History_of_programming_languages

31. PHP PHP is the most widely used scripting language for web programming. PHP extends HTML pages by adding server-executed code segments to HTML pages. The output of the execution of the PHP code is merged into the HTML page. <?php echo "Hello World. Today is ".date("l").". "; ?>How are you? Hello World. Today is Wednesday. How are you?

32. JavaScript JavaScript is a C-like programming language that can be included in an HTML web page. JavaScript allows the builder of a web page to embed dynamic elements within a web page. JavaScript programs run in the browser (i.e. the Client) <script type="text/javascript"> document.write("Hello World. Today is " + Date() ); </script>

33. MySQL MySQL is one of the most popular free and open source database engines in the market place. MySQL powers Facebook, Yahoo!, WordPress, Drupal, Joomla, and millions of other dynamic web sites. INSERT INTO users VALUES('Smith', 'John', 'jsmith@mysite.com'); SELECT surname,firstname FROM users WHERE email='jsmith@mysite.com';

34. The History of PHP • Rasmus Lerdorf • Not a trained computer scientist • Consultant building dynamic web sites - got tired of doing the same thing over and over in C • Reusable bits + HTML Templates http://www.vimeo.com/6215179

35. JavaScript: Brendan Eich • Invented JavaScript in May 1995 in ten days

36. Apache Web Server • Originally Developed at National Center for Supercomputing Applications in 1994 • Open Source • First project / product of the Apache Foundation • Brian Behlendorf founded Apache http://www.vimeo.com/3800796