Question

i’m having some problem with jquery scrollextend plugin. the objective was to to get some html elements from load_messages.php and insert it into an html page. The problem is that when i reload the html page (i.e call the load_messages.php more than once) i get the error:

Notice:Undefined variable: data in functions.php.

I couldn’t figure out exactly what is causing this problem as the php variable $data is previously defined. anyone can please help?

the jquery code is shown below:

//scroll
$('.scroll_container').scrollExtend(
        {
            'target': '#wall_container',
            'url': 'load_messages.php',


        }
    );

the load_messages.php contains the following code(i omitted the unnecessary code blocks) :

<?php
include_once 'functions.php';

$user_id=$_SESSION['user_id'];
$Wall = new Wall_Updates();
$table="friends".$user_id;
$updatesarray=$Wall->Updates($table,$user_id,$upper_limit,$lower_limit);
?>

The update function in function.php is the following:

  public function Updates($table,$user_id,$upper_limit,$lower_limit) 
{

    $query = mysql_query("SELECT user.user_id, first_name, post_content,post_id,UNIX_TIMESTAMP( created ) AS time
                          FROM user, posts
                          WHERE (
                          user.user_id
                          IN (

                          SELECT friends_id
                          FROM $table)
                          OR user.user_id =$user_id)
                          AND user.user_id = posts.user_id
                          order by post_id desc
                          LIMIT $lower_limit , $upper_limit") or die(mysql_error());
     while($row=mysql_fetch_array($query))
     {
    $data[]=$row;
      }
    return $data;

}

Answer 1

You’re initializing $data inside your while loop, which means that it’s not available to anything outside of the loop. If you want to store values from a loop, initialize the variable outside of the loop.

public function Updates($table,$user_id,$upper_limit,$lower_limit) 
{

    $query = mysql_query("SELECT user.user_id, first_name, post_content,post_id,UNIX_TIMESTAMP( created ) AS time
                          FROM user, posts
                          WHERE (
                          user.user_id
                          IN (

                          SELECT friends_id
                          FROM $table)
                          OR user.user_id =$user_id)
                          AND user.user_id = posts.user_id
                          order by post_id desc
                          LIMIT $lower_limit , $upper_limit") or die(mysql_error());

     $data = array();
     while($row=mysql_fetch_array($query))
     {
         $data[]=$row;
     }
     return $data;

}