CGS 3066: Web Programming and Design Spring 2016 Introduction to Server-Side Programming

Static Web Page Up until now, all our efforts have been put to design “static” pages only: 1. Client requests URL: 2. Browser finds the IP address of server: http://ww2.cs.fsu.edu 3. Browser sends HTTP request to GET /~mollah/path/to/webpage.html/~mollah/path/to/webpage.html 4. The server finds the “document root” of its user “mollah”: /home/grads/mollah 5. Appends the remaining URL with document root to obtain filename /home/grads/mollah/path/to/webpage.html 6. Returns file content(HTML,CSS,Javascript) as HTTP Response to client -exactly as the programmer wrote

Dynamic Web Pages Server responds “dynamically“ Returns different client-side code depending on the situation Example: GET Server determines the user through authentication (facebook login ID and password) Looks up user-specific information(e.g. wall posts, inbox, chat history) from database Generates Client side code(HTML+CSS+Javascript) to containing these content Returns dynamically generated contents as HTTP response Requires programming logic on the Server Side!

Server Side Technologies: HTTP Servers Software Responsible for handling HTTP requests, invoke server side programming Apache: the most popular web server software Free and Open-source Supports a wide variety of server-side technologies Internet Information Services(IIS): Popular web server created by Microsoft Created for use with windows NT/server Better suited for (and heavily dependent on) Windows technologies,

Server Side Technologies: Databases A number of Relational database management systems(RDBMS) are currently in use: Uses SQL (Structured Query language) to manage(insert/update/search) data Server-Client Architecture: Oracle: Proprietary, most widely used in medium and large businesses SQL Server : Proprietary RDBMS from Microsoft MySQL (open source) : most popular open-source database PostgreSQL(open source): powerful, SQL standard compliant RDBMS Serverless Architechture: SQLite: lightweight, embedded SQL database engine. Stores database in a file

Server Side Programming:CGI Stands for “Common Gateway Interface” Pass HTTP request and parameters to an executable (called “CGI scripts”) Executable returns dynamically generated web content Pros: CGI scripts can be written in any language(Perl, C/C++,Python, Bash script) Cons: Slow, Resource Intensive scripts may contain exploitable bugs, remote user may end up executing commands on the server

Server Side Programming: ASP.NET “Active Server Page”, part of.NET framework developed by Microsoft Supports visual editing (drag and drop web controls).NET framework supports many programming languages such as Visual basic, C++, C#,J# Used to run on Windows only, currently being extended into a cross- platform framework

Server Side Programming: PHP Acronym for “PHP: Hypertext Preprocessor” Open-source language for server-side scripting Easy, yet powerful tool for writing dynamic web pages quickly Relatively flat learning curve Free! Efficient alternative to competitors such as Microsoft's ASP.NET All major content management sytems currently in use (WordPress, Drupal, Joomla) are written in PHP Also facebook.com, yahoo.com, Wikipedia.org, sourceforge.net!

PHP Sneak peek Pages with PHP scripts are saved with.php extension If an http request is for a file with.html extension, server simply returns that file However, If the request is for a.php file: Server reads the file to see if any script code (PHP) is embedded in it If there is PHP code, server executes the code and sends whatever is generated PHP code snippets are interspersed within HTML content PHP code begins with Let’s try ”Hello world” with PHP!

Learning Server-Side programming Unlike HTML, CSS and Javascript, Server-side scripts cannot be tested on browser Must run on a server (therefore called “server-side”) ww2 server runs Apache HTTP server with PHP MySQL databases may only be created on the DB server(dbsrv.cs.fsu.edu). Contact systems group(again!!) to get access to dbsrv. SQLite may be used on ww2 server space Will be discussed in due time

Learning Server-Side programming Alternatively, you can set up your own HTTP server(Apache), database(MySQL/SQLite) and scripting language(PHP) on your computer! Individual installing and configuration can be too tedious Solution: Use prepackaged software bundle: WampServer: (A)pache, (M)ySQL, (P)HP bundle for (W)indows platform MAMP: My Apache - MySQL – PHP For OS X and Windows Ampps: Cross platform(available for windows, MAC OS X and Linux)