PHP 5/MySQL Programming- P9 pps

18 P H P 5 /M y S Q L P r o g r a m m i n g f o r t h e A b s o l u t e B e g i n n e r You can determine whether PHP added support for MySQL by looking again at the results of the phpInfo() function. If exposing the php_mysql.dll extension didn’t work on its own, you may have to locate the libmysql.dll file and move it to the C:\Windows directory. I also added support for two graphics libraries that I occasionally use. The gd2 library allows me to build and modify graphics, and ming allows me to create Flash movies. Don’t worry about exposing these files until you’re comfortable with basic PHP programming. However, when you’re ready, it’s really nice to know that you can easily add to the PHP features by supporting new modules. Some of the documentation that came with version 5.0 of PHP indicated that MySQL support is built in and doesn’t need to be added through the configuration file. (In fact, this information is inside the configuration file as a comment.) When I ran phpInfo(), I found that MySQL support was not built in, so I added it through the extension command. The sad truth is you can’t always trust the documentation. Take a look at the extension_dir variable in php.ini to see where PHP expects to find all your extension files. Any .dll file in that directory can be an extension. You can also download new extensions and install them when you are ready to expand PHP’s capabilities. Because of space limitations, I was unable to include information on graphics programming in PHP in this book. However, you can always check on my PHP Web site (http://shelob.cs.iupui.edu:18011/n342) for examples and tutorials on these techniques. Creating the Tip of the Day Program Way back at the beginning of this chapter, I promised that you would be able to write the featured Tip of the Day program. This program requires HTML, CSS, and one line of PHP code. The code shows a reasonably basic page: <html> <head> <title>Tip of the day</title> </head> <body> <center> TRICK TRAP TRICK <h1>Tip of the day</h1> <div style = “border-color:green; border-style:groove; border-width:2px”> <? readfile(“tips.txt”); ?> </div> </center> </body> </html> The page is basic HTML. It contains one div element with a custom style setting up a border around the day’s tip. Inside the div element, I added PHP code with the <? and ?> devices. This code calls one PHP function called readFile(). The readFile() command takes as an argument the name of some file. It reads that file’s contents and displays them on the page as if it were HTML. As soon as that line of code stops executing (the text in the tips.txt file has been printed to the Web browser), the ?> symbol indicates that the PHP coding is finished and the rest of the page will be typical HTML. Summary You’ve already come a very long way. You’ve learned or reviewed all the main HTML objects. You installed a Web server on your computer. You added PHP. You changed the Apache configuration to recognize PHP. You saw how PHP code can be integrated into an HTML document. You learned how to change the configuration file for PHP to incorporate various extensions. Finally, you created your first page, which includes all these elements. You should be proud of your efforts already. In the next chapter you more fully explore the relationship between PHP and HTML and learn how to use variables and input to make your pages do interesting things. 19 C h a p t e r 1 E x p l o r i n g t h e P H P E n v i r o n m e n t 20 P H P 5 /M y S Q L P r o g r a m m i n g f o r t h e A b s o l u t e B e g i n n e r CHALLENGES 1. Create a Web-based version of your resume, incorporating headings, lists, and varying text styles. 2. Modify one of your existing pages so it incorporates CSS styles. 3. Install a practice configuration of Apache, PHP, and MySQL (or some other package). 4. Build a page that calls the phpInfo() command and run it from your Web server. Ensure that you have a reasonably recent version of PHP installed on the server. I n chapter 1, “Exploring the PHP Environment,” you learn the foundations of all PHP programming. If you have your environment installed, you’re ready to write some PHP programs. Computer programs are ultimately about data. In this chapter you begin looking at the way programs store and manipulate data in variables. Specifically, you learn how to: • Create a variable in PHP • Recognize the main types of variables • Name variables appropriately • Output the values of variables in your scripts • Perform basic operations on variables • Read variables from an HTML form U s i n g V a r i a b l e s a n d I n p u t 2 CHAPTER Introducing the Story Program By the end of this chapter you’ll be able to write the program, called Story, featured in Figures 2.1 and 2.2. The program asks the user to enter some values into an HTML form and then uses those values to build a custom version of a classic nursery rhyme. The Story program works like most server-side programs. It has two distinctive parts: a form for user input, and a PHP program to read the input and produce some type of feedback. First, the user enters information into a plain HTML form and hits the submit button. The PHP program doesn’t execute until after the user has submitted a form. The program takes the information from the form and does something to it. Usually, the PHP program returns an HTML page to the user. 22 P H P 5 /M y S Q L P r o g r a m m i n g f o r t h e A b s o l u t e B e g i n n e r FIGURE 2.1 The program begins by asking the user to enter some information. . You added PHP. You changed the Apache configuration to recognize PHP. You saw how PHP code can be integrated into an HTML document. You learned how to change the configuration file for PHP to. ready to expand PHP s capabilities. Because of space limitations, I was unable to include information on graphics programming in PHP in this book. However, you can always check on my PHP Web site. 18 P H P 5 /M y S Q L P r o g r a m m i n g f o r t h e A b s o l u t e B e g i n n e r You can determine whether PHP added support for MySQL by looking again at the results of the phpInfo() function. If exposing the php_ mysql.dll extension didn’t work on its own,