/**
* Find next and previous articles relative to a provided threshold level
*
* @param int $id The "pivot" article's id; use zero (0) to indicate $thisarticle
* @param scalar $threshold The value to compare against if $id != 0
* @param string $s string Optional section restriction if $id != 0
* @return array An array populated with article data from the next and previous article
*/
function getNextPrev($id = 0, $threshold = null, $s = '')
{
if ($id !== 0) {
// Pivot is specific article by ID: In lack of further information, revert to default sort order 'Posted desc'
$atts = filterAtts(array('sortby' => 'Posted', 'sortdir' => 'desc'));
} else {
// Pivot is $thisarticle: Use article attributes to find its neighbours
assert_article();
global $thisarticle;
if (!is_array($thisarticle)) {
return array();
}
$atts = filterAtts();
$m = preg_split('/\\s+/', $atts['sort']);
if (empty($m[0]) || count($m) > 2 || preg_match('/[),]/', $m[0])) {
// Either no explicit sort order or a complex clause, e.g. 'foo asc, bar desc' or 'FUNC(foo,bar) asc'
// Fall back to chronologically descending order
$atts['sortby'] = 'Posted';
$atts['sortdir'] = 'desc';
} else {
// sort is like 'foo asc'
$atts['sortby'] = $m[0];
$atts['sortdir'] = isset($m[1]) && strtolower($m[1]) == 'desc' ? 'desc' : 'asc';
}
// atts w/ special treatment
switch ($atts['sortby']) {
case 'Posted':
$threshold = 'from_unixtime(' . doSlash($thisarticle['posted']) . ')';
$threshold_type = 'cooked';
break;
case 'Expires':
$threshold = 'from_unixtime(' . doSlash($thisarticle['expires']) . ')';
$threshold_type = 'cooked';
break;
case 'LastMod':
$threshold = 'from_unixtime(' . doSlash($thisarticle['modified']) . ')';
$threshold_type = 'cooked';
break;
default:
// retrieve current threshold value per sort column from $thisarticle
$acm = array_flip(article_column_map());
$key = $acm[$atts['sortby']];
$threshold = $thisarticle[$key];
$threshold_type = 'raw';
break;
}
$s = $thisarticle['section'];
}
$thenext = getNeighbour($threshold, $s, '>', $atts, $threshold_type);
$out['next_id'] = $thenext ? $thenext['ID'] : '';
$out['next_title'] = $thenext ? $thenext['Title'] : '';
$out['next_utitle'] = $thenext ? $thenext['url_title'] : '';
$out['next_posted'] = $thenext ? $thenext['uposted'] : '';
$theprev = getNeighbour($threshold, $s, '<', $atts, $threshold_type);
$out['prev_id'] = $theprev ? $theprev['ID'] : '';
$out['prev_title'] = $theprev ? $theprev['Title'] : '';
$out['prev_utitle'] = $theprev ? $theprev['url_title'] : '';
$out['prev_posted'] = $theprev ? $theprev['uposted'] : '';
return $out;
}
/**
* Find next and previous articles relative to a provided threshold level.
*
* @param int $id The "pivot" article's id; use zero (0) to indicate $thisarticle
* @param scalar $threshold The value to compare against if $id != 0
* @param string $s Optional section restriction if $id != 0
* @return array An array populated with article data
*/
function getNextPrev($id = 0, $threshold = null, $s = '')
{
if ($id !== 0) {
// Pivot is specific article by ID: In lack of further information,
// revert to default sort order 'Posted desc'.
$atts = filterAtts(array('sortby' => "Posted", 'sortdir' => "DESC"));
} else {
// Pivot is $thisarticle: Use article attributes to find its neighbours.
assert_article();
global $thisarticle;
if (!is_array($thisarticle)) {
return array();
}
$atts = filterAtts();
$m = preg_split('/\\s+/', $atts['sort']);
// If in doubt, fall back to chronologically descending order.
if (empty($m[0]) || count($m) > 2 || !preg_match('/^(?:[0-9a-zA-Z$_\\x{0080}-\\x{FFFF}]+|`[\\x{0001}-\\x{FFFF}]+`)$/u', $m[0])) {
$atts['sortby'] = "Posted";
$atts['sortdir'] = "DESC";
} else {
// Sort is like 'foo asc'.
$atts['sortby'] = $m[0];
$atts['sortdir'] = isset($m[1]) && strtolower($m[1]) == 'desc' ? "DESC" : "ASC";
}
// Attributes with special treatment.
switch ($atts['sortby']) {
case 'Posted':
$threshold = "FROM_UNIXTIME(" . doSlash($thisarticle['posted']) . ")";
$threshold_type = 'cooked';
break;
case 'Expires':
$threshold = "FROM_UNIXTIME(" . doSlash($thisarticle['expires']) . ")";
$threshold_type = 'cooked';
break;
case 'LastMod':
$threshold = "FROM_UNIXTIME(" . doSlash($thisarticle['modified']) . ")";
$threshold_type = 'cooked';
break;
default:
// Retrieve current threshold value per sort column from $thisarticle.
$acm = array_flip(article_column_map());
$key = $acm[$atts['sortby']];
$threshold = $thisarticle[$key];
$threshold_type = 'raw';
break;
}
$s = $thisarticle['section'];
}
$out['next'] = getNeighbour($threshold, $s, '>', $atts, $threshold_type);
$out['prev'] = getNeighbour($threshold, $s, '<', $atts, $threshold_type);
return $out;
}
