y3DxCTRW

1CREATE TABLE IF NOT EXISTS "user" (
2  "id" INTEGER PRIMARY KEY AUTOINCREMENT,
3  "username" TEXT UNIQUE,
4  "passwordHash" TEXT
5);
6	
7public function insertUser( $username, $passwordHash ) {
8    try {
9      $stmt = $this->db->prepare( '
10        INSERT INTO "user" ("username", "passwordHash")
11        VALUES (:username, :passwordHash);
12      ' );
13      $stmt->execute( [
14        'username'     => $username,
15        'passwordHash' => $passwordHash
16      ] );
17
18      // return the id of the newly created user
19      return $this->db->lastInsertId();
20    }
21    catch( PDOException $e ) {
22      // in sqlite an error code 19 indicates a constraint violation
23      if( $e->errorInfo[ 1 ] === 19 ) {
24        // if the constraint that is violated is user.username
25        if( false !== strpos( $e->errorInfo[ 2 ], 'user.username' ) ) {
26          // throw a custom exception that we could deem recoverable
27          throw new UserAlreadyExistsException( $username, $e );
28        }
29      }
30
31      // an unknown error occurred, re-throw the original exception
32      throw $e;
33    }
34}
35
36class UserAlreadyExistsException extends RuntimeException {
37  private $username;
38
39  public function __construct( $username, $previous = null ) {
40    parent::__construct( 'User already exists', 0, $previous );
41    $this->username = $username;
42  }
43
44  public function getUsername() {
45    return $this->username;
46  }
47}
48	
49try {
50  $username = $_POST[ 'username' ];
51  $passwordHash = password_hash( $_POST[ 'password' ], PASSWORD_BCRYPT );
52  $ourPretendObjectFromAbove->insertNewUser( $username, $passwordHash );
53}
54// catch a known, recoverable, exception
55catch( UserAlreadyExistsException $e ) {
56  // not a fatal exception: show the user the following error message somehow
57  $errorMessage = sprintf( 'Username %s is already taken', $e->getUsername() );
58}
59// catch any other exception
60catch( Exception $e ) {
61  // unexpected / fatal exception: needs immediate developer's attention
62  $logger->logException( $e );
63  $mailer->mailDeveloper( $e );
64  header( 'HTTP/1.1 500 Internal Server Error', true, 500 );
65  // show the user the following error message somehow
66  $errorMessage = 'An internal error occurred. Our developers will take a look at it';
67}