/**
* Skip to previous/next Item
*
* If several items share the same spot (like same issue datetime) then they'll get all skipped at once.
*
* @param string prev | next (relative to the current sort order)
*/
function &get_prevnext_Item($direction = 'next', $types = '', $featured = NULL, $post_navigation = 'same_blog')
{
global $DB, $ItemCache, $posttypes_specialtypes;
if (!$this->single_post) {
// We are not on a single post:
$r = NULL;
return $r;
}
/**
* @var Item
*/
$current_Item = $this->get_by_idx(0);
if (is_null($current_Item)) {
// This happens if we are on a single post that we do not actually have permission to view
$r = NULL;
return $r;
}
if (in_array($current_Item->ptyp_ID, $posttypes_specialtypes)) {
// We are not on a REGULAR post -- we cannot navigate:
$r = NULL;
return $r;
}
if (!empty($this->prevnext_Item[$direction][$post_navigation])) {
return $this->prevnext_Item[$direction][$post_navigation];
}
$next_Query = new ItemQuery($this->Cache->dbtablename, $this->Cache->dbprefix, $this->Cache->dbIDname);
// GENERATE THE QUERY:
/*
* filtering stuff:
*/
$next_Query->where_chapter2($this->Blog, $this->filters['cat_array'], $this->filters['cat_modifier'], $this->filters['cat_focus']);
$next_Query->where_author($this->filters['authors']);
$next_Query->where_author_logins($this->filters['authors_login']);
$next_Query->where_assignees($this->filters['assignees']);
$next_Query->where_assignees_logins($this->filters['assignees_login']);
$next_Query->where_author_assignee($this->filters['author_assignee']);
$next_Query->where_locale($this->filters['lc']);
$next_Query->where_statuses($this->filters['statuses']);
// types param is kept only for the case when some custom types should be displayed
$next_Query->where_types(!empty($types) ? $types : $this->filters['types']);
$next_Query->where_keywords($this->filters['keywords'], $this->filters['phrase'], $this->filters['exact']);
// $next_Query->where_ID( $this->filters['post_ID'], $this->filters['post_title'] );
$next_Query->where_datestart($this->filters['ymdhms'], $this->filters['week'], $this->filters['ymdhms_min'], $this->filters['ymdhms_max'], $this->filters['ts_min'], $this->filters['ts_max']);
$next_Query->where_visibility($this->filters['visibility_array']);
$next_Query->where_featured($featured);
/*
* ORDER BY stuff:
*/
if ($direction == 'next' && $this->filters['order'] == 'DESC' || $direction == 'prev' && $this->filters['order'] == 'ASC') {
$order = 'DESC';
$operator = ' < ';
} else {
$order = 'ASC';
$operator = ' > ';
}
$orderby = str_replace(' ', ',', $this->filters['orderby']);
$orderby_array = explode(',', $orderby);
// Format each order param with default column names:
$orderbyorder_array = preg_replace('#^(.+)$#', $this->Cache->dbprefix . '$1 ' . $order, $orderby_array);
// Add an ID parameter to make sure there is no ambiguity in ordering on similar items:
$orderbyorder_array[] = $this->Cache->dbIDname . ' ' . $order;
$order_by = implode(', ', $orderbyorder_array);
// Special case for RAND:
$order_by = str_replace($this->Cache->dbprefix . 'RAND ', 'RAND() ', $order_by);
$next_Query->order_by($order_by);
// LIMIT to 1 single result
$next_Query->LIMIT('1');
// fp> TODO: I think some additional limits need to come back here (for timespans)
/*
* Position right after the current element depending on current sorting params
*
* If there are several items on the same issuedatetime for example, we'll then differentiate on post ID
* WARNING: you cannot combine criterias with AND here; you need stuf like a>a0 OR (a=a0 AND b>b0)
*/
switch ($orderby_array[0]) {
case 'datestart':
// special var name:
$next_Query->WHERE_and($this->Cache->dbprefix . $orderby_array[0] . $operator . $DB->quote($current_Item->issue_date) . ' OR ( ' . $this->Cache->dbprefix . $orderby_array[0] . ' = ' . $DB->quote($current_Item->issue_date) . ' AND ' . $this->Cache->dbIDname . $operator . $current_Item->ID . ')');
break;
case 'title':
case 'ptyp_ID':
case 'datecreated':
case 'datemodified':
case 'last_touched_ts':
case 'urltitle':
case 'priority':
$next_Query->WHERE_and($this->Cache->dbprefix . $orderby_array[0] . $operator . $DB->quote($current_Item->{$orderby_array[0]}) . ' OR ( ' . $this->Cache->dbprefix . $orderby_array[0] . ' = ' . $DB->quote($current_Item->{$orderby_array[0]}) . ' AND ' . $this->Cache->dbIDname . $operator . $current_Item->ID . ')');
break;
case 'order':
// We have to integrate a rounding error margin
$comp_order_value = $current_Item->order;
$and_clause = '';
if (is_null($comp_order_value)) {
// current Item has NULL order
if ($operator == ' < ') {
// This is needed when browsing through a descending ordered list and we reach the limit where orders are not set/NULL (ex: b2evo screenshots)
$and_clause .= $this->Cache->dbprefix . $orderby_array[0] . ' IS NULL AND ';
} else {
// This is needed when browsing through a descending ordered list and we want to browse back into the posts that have numbers (pb appears if first NULL posts is the highest ID)
$and_clause .= $this->Cache->dbprefix . $orderby_array[0] . ' IS NOT NULL OR ';
}
$and_clause .= $this->Cache->dbIDname . $operator . $current_Item->ID;
} else {
if ($operator == ' < ') {
// This is needed when browsing through a descending ordered list and we reach the limit where orders are not set/NULL (ex: b2evo screenshots)
$and_clause .= $this->Cache->dbprefix . $orderby_array[0] . ' IS NULL OR ';
}
$and_clause .= $this->Cache->dbprefix . $orderby_array[0] . $operator . ($operator == ' < ' ? $comp_order_value - 1.0E-9 : $comp_order_value + 1.0E-9) . ' OR ( ' . $this->Cache->dbprefix . $orderby_array[0] . ($operator == ' < ' ? ' <= ' . ($comp_order_value + 1.0E-9) : ' >= ' . ($comp_order_value - 1.0E-9)) . ' AND ' . $this->Cache->dbIDname . $operator . $current_Item->ID . ')';
}
$next_Query->WHERE_and($and_clause);
break;
case 'RAND':
// Random order. Don't show current item again.
$next_Query->WHERE_and($this->Cache->dbprefix . 'ID <> ' . $current_Item->ID);
break;
default:
echo 'WARNING: unhandled sorting: ' . htmlspecialchars($orderby_array[0]);
}
// GET DATA ROWS:
// We are going to proceed in two steps (we simulate a subquery)
// 1) we get the IDs we need
// 2) we get all the other fields matching these IDs
// This is more efficient than manipulating all fields at once.
// Step 1:
$step1_sql = 'SELECT DISTINCT ' . $this->Cache->dbIDname . $next_Query->get_from() . $next_Query->get_where() . $next_Query->get_group_by() . $next_Query->get_order_by() . $next_Query->get_limit();
//echo $DB->format_query( $step1_sql );
// Get list of the IDs we need:
$next_ID = $DB->get_var($step1_sql, 0, 0, 'Get ID of next item');
//pre_dump( $next_ID );
// Step 2: get the item (may be NULL):
$this->prevnext_Item[$direction][$post_navigation] =& $ItemCache->get_by_ID($next_ID, true, false);
return $this->prevnext_Item[$direction][$post_navigation];
}
