/**
* Evaluates the GRPAH clause if there is one. Checks if
* the GRAPH clause contains an IRI, variable or nothing.
* Returns an array which contains the graphs that has to be matched.
*
* @param GraphPattern $pattern
* @param Array $graphlist
* @return Array
*/
protected function _checkGraphs(&$pattern, $graphlist)
{
$gr = $pattern->getGraphname();
if ($gr instanceof Resource) {
if ($graphlist[0] == null || in_array($gr, $graphlist)) {
$newGraphList['list'][] = $gr;
$newGraphList['var'][] = null;
} else {
return false;
}
} elseif (is_string($gr)) {
$newGraphList['list'] = $graphlist;
$newGraphList['var'][] = $gr;
} else {
$newGraphList['list'] = $graphlist;
$newGraphList['var'][] = null;
}
return $newGraphList;
}
