PHP Decode

<?   
function accordion_pages() { 
    global $post; 
    $output_markup = '<div class="panel-group" id="left-menu" role="navigation">'; 
    $ancestors   = get_post_ancestors( $post->ID ); 
    $root = count( $ancestors ) - 1; 
    $oldest_parent = ($ancestors) ? $ancestors[$root]: $post->ID; 
    $mypages = get_pages( array( 'sort_column' => 'menu_order','child_of' => $oldest_parent, 'hierarchical' => 0, 'parent' => $oldest_parent ) ); 
    $counter = 1; 
 
    foreach( $mypages as $page ) { 
        $children = get_pages( array( 'sort_column' => 'menu_order','child_of' => $page->ID ) ); 
 
        $output_markup .= '<div class="panel panel-default">'; 
        if ( $children ) { 
            $output_markup .= '<div class="panel-heading has-children">' .  
			 
                                '<a class="title-link" href="' . get_page_link( $page->ID ) . '">' .  $page->post_title . '</a>' . 
								 
                                '<a class="pull-right" data-toggle="collapse" data-parent="#left-menu"href="#collapse' . $counter . '">' . 
                                    '<span class="glyphicon glyphicon-triangle-bottom" aria-hidden="true"></span>' . 
                                '</a>' . 
                            '</div>' .  
                            '<div id="collapse' . $counter . '" class="panel-collapse collapse">' . 
                                '<div class="panel-body">'; 
 
            foreach( $children as $child ) { 
                $output_markup .= '<a style="color:#660000;" href="' . get_page_link( $child->ID ) . '"><span class="glyphicon glyphicon-minus" aria-hidden="true"></span> ' . $child->post_title . '</a><div class="divider sonDivider"></div>'; 
            } 
            $output_markup .= '</div></div>'; 
 
        } else { 
            $output_markup .= '<div class="panel-heading">' .  
                                '<a class="title-link" href="' . get_page_link( $page->ID ) . '">' . $page->post_title . '</a>'. 
								'</div>'; 
        } 
 
        $output_markup .= '</div>'; 
        $counter++; 
    } 
    $output_markup .= '</div>'; 
    return $output_markup; 
} ?>