Page 304 - Beginning PHP 5.3

Part III: Using PHP in Practice
Summary

This chapter has shown you how to deal with Web forms within your PHP scripts. You learned:

❑ How to create Web forms, including all the different types of controls that you can place in
a form
❑ All about the $_GET , $_POST , and $_REQUEST superglobals, and how your scripts can use them
to capture form data sent by a user
❑ Some of the security issues surrounding Web forms, and how to mitigate them
❑ How to deal with empty form fields
❑ How to get the PHP engine to recognize multi - value fields, and how to read the data that these
fields send
❑ How to generate Web forms from within your PHP scripts. This allows you to add more
interactivity and flexibility to your forms. You worked through an example of creating such an
interactive form
❑ The concept of hidden form fields and how to use them to store data between page requests.
You used this technique to create a three - stage registration form
❑ How to handle files uploaded via Web forms, including using the $_FILES superglobal to read
information about uploaded files
❑ How to redirect the browser after a form submission in order to display a thank - you page and
avoid issues with page reloads
HTML forms are a great way to add interactivity to your Web applications. You can use the skills you ’ ve
learned in this chapter to produce a wide variety of interactive Web forms, from contact forms and
registration scripts through to login forms, online store checkout forms, and “ tell - a - friend ” functions.
In the next chapter you look at how to store application data between page requests, which means your
PHP applications can have a longer lifetime than just a single page view. Meanwhile, try the following
two exercises to test your form - handling knowledge. You can find the solutions to these exercises in
Appendix A.

Exercises
1. Write a simple number - guessing game in PHP. The script should “ think ” of a random number
between 1 and 100, then give the user five chances to guess the number. For each guess, the
script should report whether the guessed number was too low, too high, or correct. (Hint: Use
rand( 1, 100 ) to generate a random number between 1 and 100.)
2. Create a script that displays a form allowing the user to select one of three Amazon stores —
amazon.com , amazon.ca, and amazon.co.uk — and then jumps to the relevant store based on

the user ’ s choice.
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