Page 447 - Beginning PHP 5.3

Chapter 14: Manipulating MySQL Data with PHP
You may recognize these functions from Chapter 9 (although they ’ ve been slightly modified).
validateField() checks to see if the supplied field name is within the list of fields that the user
forgot to fill in. If it is, a class= “ error ” attribute is output, which highlights the missing field
in red.

Meanwhile, setChecked() and setSelected() output the markup to pre - check a checkbox and
pre - select an option in a menu, respectively. Both methods expect an object derived from the
DataObject class (such as a Member object), the name of the field to look up, and the value to
compare. If the supplied value matches the value of the field in the object, the markup is output.
These functions are used within the registration form to help prefill fields in the form, as you see in a
moment.

Enhancing the Member Class
The next thing to do is add some more functionality to your Member class. First, add a couple of extra
methods for retrieving Member objects from the database. getByUsername() retrieves the member with
the supplied username, and getByEmailAddress() retrieves the member with the given email address.
These will be used to ensure that a prospective member doesn ’ t accidentally register with a username or
email address that is already in the database.

Open up the Member.class.php file that you created in Chapter 13 and add the following code to the
file, after the existing getMember() method:

public static function getByUsername( $username ) {
$conn = parent::connect();
$sql = “SELECT * FROM “ . TBL_MEMBERS . “ WHERE username = :username”;

try {
$st = $conn- > prepare( $sql );
$st- > bindValue( “:username”, $username, PDO::PARAM_STR );
$st- > execute();
$row = $st- > fetch();
parent::disconnect( $conn );
if ( $row ) return new Member( $row );
} catch ( PDOException $e ) {
parent::disconnect( $conn );
die( “Query failed: “ . $e- > getMessage() );
}
}

public static function getByEmailAddress( $emailAddress ) {
$conn = parent::connect();
$sql = “SELECT * FROM “ . TBL_MEMBERS . “ WHERE emailAddress =
:emailAddress”;

try {

409

9/21/09 9:14:04 AM
c14.indd 409
c14.indd 409 9/21/09 9:14:04 AM