Why does this block my PHP code?

The query is

$q1 = "SELECT * from `event` ORDER BY `upload_date` DESC";

This is the function

function display_content($r, $dis){

foreach($r as $part) {

$dis .= '<br /><div id="event_box">';
$dis .= '<div id="event_name"><a href = " http://'.$part['link'].'" target="_blank"> '.$part['name'].'</a></div>';
$dis .= '<div id="start_date"><b>From: </b>'.$part['start_date'].' </div>';
$dis .= '<div id="end_date"><b>Until: </b>'.$part['end_date'].' </div>';
$dis .= '<div id="event_link"><b>Link: </b><a href = " http://'.$part['link'].'" target="_blank">Event Website</a></div>';
$dis .= '<div id="event_venue"><b>Venue: </b>'.$part['venue'].' </div>';

$a = array(854, 480);
$b = array(300, 300);
$str = $part['embed_code'];
$partVideo = str_replace($a, $b, $str);

$dis .= '<div id="event_video"> '.$partVideo.' </div>';

$dis .= '<div id="event_image"><a href = " http://'.$part['link'].'" target="_blank"><img src = "data:image;base64, '.$part['image'].'"';
$dis .= 'alt = "'.$part['name'].'"></a></div>';
$dis .= '<div id="details">  '.$part['details'].'<br /><br />';
$dis .= '<button class="share2 btn-primary  s_twitter">Tweet!</button>&nbsp&nbsp';
$dis .= '<button class="share2 btn-primary  s_facebook">Share on Facebook!</button></div>';
$dis .= '</div>';
$dis .= '<br />';

}

echo $dis;

} // close function display content

Later on I call

display_content($r1, $display);

Only the first instance (entry) of an event from the database appears, and it appears fine (name, venue, details etc), but all the other event entries do not appear at all. Like they are 'blocked' maybe.

However, they all appear fine if I remove the line

 $dis .= '<div id="event_video"> '.$partVideo.' </div>';

Entries either have a

$dis .= '<div id="event_image"><a href = " http://'.$part['link'].'" target="_blank"><img src = "data:image;base64, '.$part['image'].'"';
$dis .= 'alt = "'.$part['name'].'"></a></div>';

or a

 $dis .= '<div id="event_video"> '.$partVideo.' </div>';

'$dis' or what '$dis' represents in the function is defined/instantiated ($dis = '';) outside of the function so should be a global variable.

What is going on and how can I fix it?

I know that they don't all have the same image / video information, which probably means I should normalise my database better (these entries are NULL in the database until I fill them), but shouldn't they all appear / print on screen anyhow?

Why is only the first event appearing?

Thanks!

'<div id="event_video"> '.$partVideo.' </div id="event_video">';

That's not how you close an HTML tag...You should be using:

'<div id="event_video"> '.$partVideo.' </div>';

Double check your code, and make sure you have proper HTML markup. You've done this in multiple locations.

Also, you may want to do a var_dump( $partVideo ) to verify whether or not you can actually concatenate that variable with the string, and to ensure that it isn't responsible for "breaking" the rest of your code.