PHP 5 in Practice

10. Web Form Handling As started in Chapter 9, "Web Page Creation/XHTML/CSS," this chapter continues to demonstrate PHP's capabilities when used in the web server-side environment. The first section demonstrates how form data is ea...

10.1. Easily Obtaining Form Data One of the best features of PHP that many programmers find is how easily it handles form data. PHP automatically populates two superglobal arrays, $_GET and $_POST, with all the values sent as GET or POST data, res...

10.2. Obtaining Multidimensional Arrays of Form Data What makes the automatic form data handling described in the preceding section, "Easily Obtaining Form Data," even more powerful, is PHP's capability to understand multidimensional dat...

10.3. Using GET and POST Form Data Together Because GET and POST variables are both passed in separately, you can use them both at the same time, even having the same variable names in both cases. The most common practice of this is to pass some c...

10.4. Accepting Uploaded Files PHP also provides a straightforward manner in which to handle file uploads as well. Anytime that you have a file upload field on your web page, the $_FILES array is automatically filled in for you with various pieces...

10.5. Generating Select Statements Web applications often need to have a list of options repeated many times on the same web page. These might be a list of countries, states, classes of data, and so on. Even more often, this information may come f...

10.6. Requiring Certain Fields to Be Filled Out Often when accepting data from a user, certain fields on a form must be filled out. A common tactic to ensure this is to use JavaScript to check/require that every field is filled before submitting...

10.7. Manipulating Text for Display on Bulletin Boards (BBCode) Bulletin board or blog systems often want to strip HTML but allow for special formatting characters to be employed by the users. This is known as BBCode (short for Bulletin Board Co...

10.8. Accepting and Displaying User Data Giving Warnings for Links There is one final manipulation of user submitted data that is regularly done. If the script allows users to include URLs in their data, the user could make the link say somethin...

10.9. Preventing Multiple Form Submissions For a number of reasons you may need to prevent a form from being submitted multiple times. If you don't, you can end up with duplicate records. This can be caused by a careless user who submits a form on...