Code library

So far, we've been adding the functions to the end of the PHP file. That makes them difficult to share, though.

Let's put the functions in a separate file, in a library folder. Let's all the file... useful-functions.php. Any name will do.

I'll also put our CSS files in the library folder.

Library folder with files

useful-functions.php has to have a start-php thing at the top:

  • <?php

Sometimes I forget that.

Now, I'll add one line to the main PHP program.

  • <?php
  • require_once 'library/useful-functions.php';
  • // Set up vars to track results.
  • $errorMessages = ''; // Composite error messsage.

There are other ways to include files, but we'll only use require_once.

Oh, the CSS file moved into library, so...

  • <link rel="stylesheet" href="library/styles.css">

That's it! Now, we can reuse the validation functions as needed.



Reuse your code across programs, using functions and page components.


That's it for validation. Now lets talk about databases.