/**
* if the selected resources changed (due to filters or limit or offset)
* we have to change the value query as well (because the resources are mentioned as subjects)
*
* @return OntoWiki_Model_Instances $this
*/
protected function updateValueQuery()
{
if ($this->_valueQueryUptodate) {
return $this;
}
$resources = $this->getShownResources();
foreach ($resources as $key => $resource) {
$resources[$key] = new Erfurt_Sparql_Query2_SameTerm($this->_resourceVar, new Erfurt_Sparql_Query2_IriRef($resource['value']));
}
if ($this->_valueQueryResourceFilter == null) {
$this->_valueQueryResourceFilter = new Erfurt_Sparql_Query2_Filter(new Erfurt_Sparql_Query2_BooleanLiteral(false));
$this->_valueQuery->addElement($this->_valueQueryResourceFilter);
}
$this->_valueQueryResourceFilter->setConstraint(empty($resources) ? new Erfurt_Sparql_Query2_BooleanLiteral(false) : new Erfurt_Sparql_Query2_ConditionalOrExpression($resources));
//fix for a strange issue where a query with only optionals fails
//(but there is a magic/unkown condition, that makes it work for some queries!?)
//if($this->_store->getBackendName() == 'ZendDb'){
$hasTriple = false;
foreach ($this->_valueQuery->getWhere()->getElements() as $element) {
if ($element instanceof Erfurt_Sparql_Query2_IF_TriplesSameSubject) {
$hasTriple = true;
break;
}
}
if (!$hasTriple) {
$this->_valueQuery->getWhere()->addElement(new Erfurt_Sparql_Query2_Triple($this->_resourceVar, new Erfurt_Sparql_Query2_Var('p'), new Erfurt_Sparql_Query2_Var('o')));
}
//}
//remove duplicate triples...
$this->_valueQuery->optimize();
$this->_valueQueryUptodate = true;
return $this;
}
