/**
* Retrieve filters based on the supported input/output type.
*
* @param $inputTypeDescription a type description that has to match the input type
* @param $outputTypeDescription a type description that has to match the output type
* NB: input and output type description can contain wildcards.
* @param $data mixed the data to be matched by the filter. If no data is given then
* all filters will be matched.
* @param $dataIsInput boolean true if the given data object is to be checked as
* input type, false to check against the output type.
* @return array a list of matched filters.
*/
function &getObjectsByTypeDescription($inputTypeDescription, $outputTypeDescription, $data = null, $dataIsInput = true)
{
static $filterCache = array();
static $objectFilterCache = array();
// We do not yet support array data types. Implement when required.
assert(!is_array($data));
// Build the adapter cache.
$filterCacheKey = md5($inputTypeDescription . '=>' . $outputTypeDescription);
if (!isset($filterCache[$filterCacheKey])) {
// Get all adapter filters.
$result =& $this->retrieve('SELECT f.*' . ' FROM filters f' . ' INNER JOIN filter_groups fg ON f.filter_group_id = fg.filter_group_id' . ' WHERE fg.input_type like ?' . ' AND fg.output_type like ?' . ' AND f.parent_filter_id = 0 AND f.is_template = 0', array($inputTypeDescription, $outputTypeDescription));
// Instantiate all filters.
$filterFactory = new DAOResultFactory($result, $this, '_fromRow', array('filter_id'));
$filterCache[$filterCacheKey] =& $filterFactory->toAssociativeArray();
}
// Return all filter candidates if no data is given to check against.
if (is_null($data)) {
return $filterCache[$filterCacheKey];
}
// Build the object-specific adapter cache.
$objectFilterCacheKey = md5($filterCacheKey . (is_object($data) ? get_class($data) : "'{$data}'") . ($dataIsInput ? 'in' : 'out'));
if (!isset($objectFilterCache[$objectFilterCacheKey])) {
$objectFilterCache[$objectFilterCacheKey] = array();
foreach ($filterCache[$filterCacheKey] as $filterCandidateId => $filterCandidate) {
/* @var $filterCandidate PersistableFilter */
// Check whether the given object can be transformed
// with this filter.
if ($dataIsInput) {
$filterDataType =& $filterCandidate->getInputType();
} else {
$filterDataType =& $filterCandidate->getOutputType();
}
if ($filterDataType->checkType($data)) {
$objectFilterCache[$objectFilterCacheKey][$filterCandidateId] =& $filterCandidate;
}
unset($filterCandidate);
}
}
return $objectFilterCache[$objectFilterCacheKey];
}
