Passing An Array Between Classes

[SpacePhoenix]

This is a generic problem I'm having but an example is below. What I'm trying to do is get the data from the database (using model classes) and pass the data via an array to the view classes (via controller classes if any processing of the data needs to be done).

The example below works fine when dealing with the data in the model class but whatever I've tried so far either results in the display of only one line of the array or a line of the array still displays but it keeps on repeating until php times out.

I'm trying to keep the model classes solely for accessing and interfacing with the data with the controllers only processing the data and the views only displaying the data (with a minor bit of processing to decide what needs viewing).

I'm trying to always use while loops over foreach loops wherever possible due to the superior performance of while loops.

As i'm still relavtivly new to OOP php, my suspision is that i don't know the proper syntax for what i'm trying to do.

method from messages_model class

      function message_inbox_get_messages($db,$user_id) {
          $sql="SELECT
              ue_messages_delivery.message_id AS message_id,
              ue_messages_delivery.sender_id AS sender_id,
              ue_messages.subject AS subject,
              ue_messages_delivery.date_sent AS date_sent
              FROM ue_messages
              INNER JOIN ue_messages_delivery
              ON ue_messages.message_id = ue_messages_delivery.message_id
              WHERE ue_messages_delivery.recipient_id = '$user_id'
              AND ue_messages_delivery.parent_id = 0 ";
          $result=$db->dbQuery($sql);
          while ( $row=$db->dbFetchArray($result) ) {
              $sent_by=$row['sender_id'];
              $message_id=$row['message_id'];
              $subject=$row['subject'];
              $from_user=$this->messages_get_sender_name($sent_by,$db);
               echo "<tr>\n";
               echo "<td>" .$from_user."</td>\n";
               echo "<td>link for selecting a message to view</td>\n";
               echo "<td>" .$row['date_sent']."</td>\n";
               echo "</tr>\n";
              $message['message_id']=$row['message_id'];              
              $message['date_sent']=$row['date_sent'];
          }
      } 

Method from messages_view class

      function display_inbox($db) {
          $user_id=4;
          echo "<h1>View Inbox</h1>";
          echo "<table class='all_messages'>\n";
          echo "<tr>";
          echo "    <th>";
          echo '        From';
          echo "    </th>\n";
          echo "    <th>";
          echo '        Subject';
          echo "    </th>\n";          
          echo "    <th>";
          echo '        Time';
          echo "    </th>\n";
          echo "</tr>";
          $num_messages=$this->messages_model->messages_count($db);
          if ( $num_messages < 1 ) {
              echo "<tr>";
              echo "<td colspan='4'>";
              echo "<div class='no_news'>No messages in your inbox</div>";
              echo "</td>";
              echo "</tr>";
          } else {
              $this->messages_model->message_inbox_get_messages($db,$user_id);
          }
          echo "</table>\n";
          echo "<div class='button'><p><a href='main_page.php?view=messages&amp;subview=write_message'>Write New Message</a></p></div>\n";
      } 

[AnthonySterling]

Ideally, your model shouldn't output HTML, if fact, it shouldn't output anything.

If for example you wanted to use the 'inbox' model to provide the user an XML feed of their messages, you cannot do this now as it outputs HTML.

Hopefully, the following should clarify a little.

<?php
class Messages
{
    public function view()
    {
        $oView = new MessagesHTMLView();
        $oModel = new MessagesModel();
        $oView->bind('messages', $oModel->getInbox(76));
        echo $oView->render();
    }
    
    public function rss()
    {
        $oView = new MessagesRSSView();
        $oModel = new MessagesModel();
        $oView->bind('messages', $oModel->getInbox(76));
        echo $oView->render();
    }
}
?>

Notice that we used the same model to display the same data 2 different ways, which is as it should be, as we only changed the view.

Your model provides the data to the view, the view can iterate the data as it's related to the view.

I hope that makes sense.

[SpacePhoenix]

SilverBulletUK, you understand only part of the problem. The array is created fine in the model but when it is returned to the view (or whatever class has happened to call it), only one row of the array is returned.

Experimenting with foreach loops and while loops + print_r and var_dump has shown that the view will only ever receive one row of the array. Once i can get the whole array and not just one row to the view then i can remove all the display output from the model.

I suspect that there is a special syntax that I need so that:

$an_arry=$another_object->model_method_to_get_data_array($database_connection,$search_value);

will return the whole array and not just like the first row of the array.

[AnthonySterling]

No, there is no special syntax for obtaining a full array rather than a partial one. They problem lies in your model, I don't see any code in the example posted that returns the data, are you?

[SirAdrian]

Do you have something like this?

$messages = array();
while ($row = $this->db->fetchRow($sql))
{
    $messages[] = $row;
}

return $messages; 

[SpacePhoenix]

I did have it in the while loop like this:

$message['subject']=$row['subject']; 

with one for each column of the array.

I tried SirAdrian's suggestion:

$messages = array();
while ($row = $this->db->fetchRow($sql))
{
    $messages[] = $row;
}

return $messages; 

And that worked a treat, thanks

On the view side of things i changed it to (after a bit more experimenting):

              foreach ($message as $user_message) {
                  extract($user_message);
                  $from_user=$this->messages_model->messages_get_sender_name($sender_id,$db);
                  echo "<td>" .$from_user."</td>\n";
                  echo "<td><a href='link for selecting a message to view'>$subject</a></td>\n";
                  echo "<td>" .$date_sent."</td>\n";
                  echo "</tr>\n";
              } 

The foreach gives me one row at a time, the extract grabs the individual variables from the from then i display them, repeated until there are no more messages to list.

Result, all data display removed from the model, thanks for the help SirAdrian. SilverBulletUK, at the time i was experimenting with another view and model where i had exactly the same problem, now i can migrate the data viewing and processing to the view or controller as appropraite.