/**
* Return the number of visitors that visited every site in the given list for the
* given date range. Includes the number of visitors that visited at least one site
* and the number that visited every site.
*
* This data is calculated on demand, and for very large tables can take a long time
* to run.
*
* See {@link Model\DistinctMetricsAggregator} for more information.
*
* @param string $idSite comma separated list of site IDs, ie, `"1,2,3"`
* @param string $period
* @param string $date
* @return array Metrics **nb_total_visitors** and **nb_shared_visitors**.
* @throws Exception if $idSite references zero sites or just one site.
*/
public function getCommonVisitors($idSite, $period, $date, $segment = false)
{
if (empty($idSite)) {
throw new Exception("No sites to get common visitors for.");
}
$idSites = Site::getIdSitesFromIdSitesString($idSite);
Piwik::checkUserHasViewAccess($idSites);
$segment = new Segment($segment, $idSites);
$period = PeriodFactory::build($period, $date);
return $this->distinctMetricsAggregator->getCommonVisitorCount($idSites, $period->getDateStart(), $period->getDateEnd(), $segment);
}
/**
* @expectedException \Exception
*/
public function test_getCommonVisitorCount_Throws_WhenOneSiteSupplied()
{
$this->instance->getCommonVisitorCount(array(1), Date::factory("2012-01-01"), Date::factory("2012-02-01"), new Segment("", array(1)));
}
