10/5/2015CS346 PHP1 Module 1 Introduction to PHP

PHP References  General: Download, documentation  Documentation: manual  PHP.net tutorial  W3schools tutorial 10/5/2015CS346 PHP2

PHP functions  Documented PHP functions  You can create your own functions too 10/5/2015CS346 PHP3

10/5/2015CS346 PHP4 Objectives  What is PHP?  How does a PHP script work with a Web Browser and a Web Server?  What software and components you need to get started with PHP?  To create and run a simple PHP script

10/5/2015CS346 PHP5 What Is PHP?  PHP, PHP Hypertext Preprocessor Server-side scripting languages for creating dynamic web pages Server-side scripting languages for creating dynamic web pages

10/5/2015CS346 PHP6 PHP advantages Advantages of Using PHP to enhance Web pages: Easy to use Easy to use Simpler than Perl Simpler than Perl Open source Open source Multiple platform. Multiple platform.

10/5/2015CS346 PHP7 How PHP Pages are Accessed and Interpreted Client: Web browserWeb server 1.Form submitted with a submit button  Action sends a request to the php file in server 3. Receive the request, find the file, and read it 4. Execute the PHP commands 5. Send the results back 6.  ---- results returned as HTML file 7. Web browser renders the HTML file, displaying the results

10/5/2015CS346 PHP8 Getting Started with PHP To develop and publish PHP scripts you need: A client machine with a basic text editor and Internet connection A client machine with a basic text editor and Internet connection Prepare a text file with.php extensionPrepare a text file with.php extension FTP or Telnet software FTP or Telnet software Upload the file.php to the serverUpload the file.php to the server A Web server with PHP built into it A Web server with PHP built into it Process the file.phpProcess the file.php

10/5/2015CS346 PHP9 WHH Note  This means that a browser e.g. IE or Firefox on the client computer will not recognize or render a file with extension.php  How do you check your PHP script before submission to server?

10/5/2015CS346 PHP10 Getting Started with PHP Set up development computer as a server Laptop contains a server and a browser environment Laptop contains a server and a browser environment Laptop is also set up as a Web server - WAMPserver Laptop is also set up as a Web server - WAMPserver Windows Apache, MySQL, PHPWindows Apache, MySQL, PHP Client machine: PC, XP, editors, browsers Client machine: PC, XP, editors, browsers Internet connection not needed Internet connection not needed Use copy and paste to transfer the scripts Use copy and paste to transfer the scripts  For class demos: localhost or or cs346 server localhost or or cs346 server

10/5/2015CS346 PHP11 Exploring the Basic PHP Development Process The basic steps you can use to develop and publish PHP pages are: 1. Create a PHP script file and save it to a local disk Test on localhost until satisfiedTest on localhost until satisfied 2. Use FTP to copy the file to the server 3. Access your file via URL on server using a browser IE, Netscape, Opera, etc.IE, Netscape, Opera, etc.

10/5/2015CS346 PHP12 Check PHP installation  Create a simple PHP script, called phpinfo.php The PHP script starts with a The PHP script starts with a Between these tags is a single PHP statement: phpinfo(); Between these tags is a single PHP statement: phpinfo();  Copy the file to a directory of local server For WAMP: wamp/www For WAMP: wamp/www  Access the file with a browser 

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Checking the server set up  Upload the phpinfo.php to cs346 server E.g. to huen/m00 E.g. to huen/m00  Click on the link   Check the various environments: Apache Apache MySQL MySQL PHP functions PHP functions variables variables 10/5/2015CS346 PHP14

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10/5/2015CS346 PHP16 Creating a PHP Script File  Create PHP script welcome.php Starts with a Starts with a Between these tags is a single PHP print statement Between these tags is a single PHP print statement  Copy the file to C:\wamp\www  Access the file with  Demo on localhost  Demo on cs346 server

Similarly for other PHP scripts  Upload welcome.php to huen/m00  Click on  /5/2015CS346 PHP17 <?PHP /* welcome.php */ print (" Welcome to PHP, CS346 class! "); /* Note the combination of html tags and css */ ?>

10/5/2015CS346 PHP18 Note the effect of CSS

10/5/2015CS346 PHP19 Alternative PHP Delimiters  You can alternatively start your PHP scripts with the tag as follows: print ("A simple initial script"); </script>  If short_open_tag enabled in its configuration file (php.ini), you can use.  If asp_tags is enabled in the PHP configuration file, you can use as delimiters.

10/5/2015CS346 PHP20 Proper Syntax  If you have a syntax error then you have written one or more PHP statements that are grammatically incorrect in the PHP language.  The print statement syntax:

10/5/2015CS346 PHP21 If syntax is wrong <?php print ( "Welcome to PHP, CS346 class!); print ( "Welcome to PHP, CS346 class!);?>

10/5/2015CS346 PHP22 A Little About PHP's Syntax  Some PHP Syntax Issues: Be careful to use quotation marks, parentheses, and brackets in pairs. Be careful to use quotation marks, parentheses, and brackets in pairs. Most PHP commands end with a semicolon (;). Most PHP commands end with a semicolon (;). Be careful of case. Be careful of case. PHP ignores blank spaces. PHP ignores blank spaces.

10/5/2015CS346 PHP23 Embedding PHP Statements Within HTML Documents  One way to use PHP is to embed PHP scripts within HTML tags in an HTML document.  Save the file first with extension html  Validate the html file  Change the extension to php  Access the script by URL on server

10/5/2015CS346 PHP24 <head> HTML With PHP Embedded HTML With PHP Embedded </head><body> Welcome To My Page! Welcome To My Page! <?PHP <?PHP print (" Using PHP is not hard!"); print (" Using PHP is not hard!"); ?> ?> and you can learn it quickly! and you can learn it quickly! </body></html>

10/5/2015CS346 PHP25 When embedded1.php is accessed

10/5/2015CS346 PHP26 Using Backslash (\) to Generate HTML Tags with print()  Sometimes you want to output an HTML tag that also requires double quotation marks. Use the backslash (“\”) character to signal that the double quotation marks themselves should be output: print (" "); Use the backslash (“\”) character to signal that the double quotation marks themselves should be output: print (" "); The above statement would output: The above statement would output:

10/5/2015CS346 PHP27 Using Comments with PHP Scripts  Comments enable you to include descriptive text along with the PHP script. Comment lines are ignored when the script runs; they do not slow down the run-time. Comment lines are ignored when the script runs; they do not slow down the run-time. Comments have two common uses. Comments have two common uses. Describe the overall script purpose.Describe the overall script purpose. Describe particularly tricky script lines.Describe particularly tricky script lines.

10/5/2015CS346 PHP28 Using Comments with PHP Scripts  Comment Syntax - Use // standalone <?php // This is a comment ?>  Can be placed on Same line as a statement: <?php print ("A simple initial script"); //Output a line ?>

10/5/2015CS346 PHP29 Example Script with Comments Generating HTML From PHP 2. Generating HTML From PHP 3. Generating HTML From PHP 3. Generating HTML From PHP 4. <?php 5. // 6. // Example script to output HTML tags 7. // 8. print ("Using PHP has some advantages: "); 9. print (" Speed Ease of use 9. print (" Speed Ease of use Functionality "); //Output bullet list Functionality "); //Output bullet list 10. print (" "); 11. ?>

10/5/2015CS346 PHP30 Alternative Comment Syntax PHP allows a couple of additional ways to create comments. <?php phpinfo(); # This is a built-in function ?>  Multiple line comments. <?php <?php/* A script that gets information about the PHP version being used. */

10/5/2015CS346 PHP31 Summary  HTML pages are static and cannot interact with users  PHP is a free, open source technology that enables documents to generate dynamic content  PHP script has the extension of.php  PHP script may be standalone or  Can be embedded in an HTML document

10/5/2015CS346 PHP32 Summary  Resources needed for development: Web server with built-in PHP Web server with built-in PHP a client machine with a basic text editor, browser, and internet connections a client machine with a basic text editor, browser, and internet connections FTP or Telnet software to send the script to the server FTP or Telnet software to send the script to the server

10/5/2015CS346 PHP33 Summary  PHP script process: write the PHP script file write the PHP script file copy the script file to the Web server copy the script file to the Web server access the file with a Web browser access the file with a Web browser  Comments can be proceeded with two forward slashes (//) two forward slashes (//) or # or # or enclosed in /* and */ or enclosed in /* and */