PHP class providing empty object

Question

My index.php page had this code that defaults the user to the homepage.

<?php 
require_once ( "config.php" );
$action = isset( $_GET['action'] ) ? $_GET['action'] : "";
switch ( $action ) {
  case 'seeAll':
    seeAll();
    break;
  case 'viewResource':
    viewResource();
    break;
  default:
    homepage();
}

function homepage() {
  $results = array();
  $learnData = Resource::getHomePageTiles( 'learn' );
  $practiceData = Resource::getHomePageTiles( 'practice' );
  $elseData = Resource::getHomePageTiles( 'else' );
  $results['learn'] = $learnData;
  $results['practice'] = $practiceData;
  $results['else'] = $elseData;
  $results['pageTitle'] = "Couch To Code";
  require_once ( "templates/homepage.php" );
}

Which calls the getHomePageTiles method of my Resource class. Here is the code for the Resource class and getHomePageTiles method.

class Resource {
  public $id = null;
  public $title = null;
  public $summary= null;
  public $url = null;
  public $content = null;
  public $category = null;
  public $is_free = null; //????
  public $is_featured = null;
  public $is_favorite = null;
  public $date_created = null;

  public function __construct( $data ) {
    if ( isset ( $data['id'] ) ) $this->id = (int) $data['id'];
    if ( isset ( $data['title'] ) ) $this->title = $data['title'];
    if ( isset ( $data['summary'] ) ) $this->summary = $data['summary'];
    if ( isset ( $data['url'] ) ) $this->url = $data['url'];
    if ( isset ( $data['content'] ) ) $this->content = $data['content'];
    if ( isset ( $data['category'] ) ) $this->category = $data['category'];
    if ( isset ( $data['is_free'] ) ) $this->is_free = (int) $data['is_free'];
    if ( isset ( $data['is_featured'] ) ) $this->is_featured = (int) $data['is_featured'];
    if ( isset ( $data['is_favorite'] ) ) $this->is_favorite = (int) $data['is_favorite'];
    if ( isset ( $data['date_created'] ) ) $this->date_created = date("Y-m-d H:i:s");
}

public static function getHomePageTiles( $type ) {
  global $DB_HOST;
  global $DB_NAME;
  global $DB_USERNAME;
  global $DB_PASSWORD;
  $conn = new mysqli( $DB_HOST, $DB_USERNAME, $DB_PASSWORD, $DB_NAME );
  if (mysqli_connect_errno()) {
    printf("Connection to the database failed: %s/n", $mysqli -> connect_error);
    exit();
  }
  $sql = "SELECT * FROM resources WHERE category = ? ORDER BY position ASC LIMIT 4;";
  if ($st = $conn->prepare( $sql )) {
    $st->bind_param( "s", $type );
    $st->execute();
    $list = array();
    while ( $row = $st->fetch() ) {
        $resource = new Resource( $row );
        $list[] = $resource;
    }
    $conn = null;
    return $list;
  } else {
    printf("Errormessage: %s\n", $conn->error);
  }
}

My Homepage.php file has the following code in it

<?php 
    foreach ( $results['learn'] as $learnTile ) { 
    print_r($learnTile);
?>
    <div class="col-md-3 col-xs-6 featured">

        <a href=".?action=viewResource&amp;resourceId= <?php echo($learnTile->id)?> ">
        <img src="#" class="thumbnail img-responsive">
        </a>
    </div>
<?php } ?>

The code is pulling the correct number of Resource objects, but something is going wring, because my link (in homepage.php) is not pulling in the id from the Resource object.

So, to debug i've printed out ($learnTile) and am getting empty objects/arrays.

 Resource Object ( [id] => [title] => [summary] => [url] => [content] => [category] => [is_free] => [is_featured] => [is_favorite] => [date_created] => )  Resource Object ( [id] => [title] => [summary] => [url] => [content] ...

Where am I going wrong? is my constructor not working? Clearly the Resource objects are pulling the null values from the original property definitions to null. I've been stumped on this one for several days so any help / guidance is appreciated. Thanks!

Are you creating a new Resource from inside the Resource class? "$resource = new Resource( $row );" That seems wrong to me. — Aaron Franco, Apr 15 '16 at 12:51
Change `while ( $row = $st->fetch() ) {` to `while ( $row = $st->fetch_row() ) {`. — syck, Apr 15 '16 at 13:05

score 1 · Accepted Answer · answered Apr 15 '16 at 12:57

1

There is never an array inside the $row. See the manual: php.net/manual/en/mysqli-stmt.fetch.php it returns a boolean only. You should bind your result when using prepare.

answered Apr 15 '16 at 12:57

Ronald Swets

1,669
10
16

yes excatly your problem is stmt-fetch returns boolean – Santa's helper Apr 15 '16 at 12:58
Thanks! I was able to find the details of how to fix my issue here: http://stackoverflow.com/questions/994041/how-can-i-put-the-results-of-a-mysqli-prepared-statement-into-an-associative-arr – Brianna Vay Apr 15 '16 at 13:47

PHP class providing empty object

1 Answers1