/**
* Main entry point for PKP statistics reports.
*
* @see <http://pkp.sfu.ca/wiki/index.php/OJSdeStatisticsConcept#Input_and_Output_Formats_.28Aggregation.2C_Filters.2C_Metrics_Data.29>
* for a full specification of the input and output format of this method.
*
* @param $metricType null|string|array metrics selection
* NB: If you want to use the default metric on journal level then you must
* set $metricType = null and add an explicit filter on a single journal ID.
* Otherwise the default site-level metric will be used.
* @param $columns string|array column (aggregation level) selection
* @param $filters array report-level filter selection
* @param $orderBy array order criteria
* @param $range null|DBResultRange paging specification
*
* @return null|array The selected data as a simple tabular result set or
* null if the given parameter combination is not supported.
*/
function getMetrics($metricType = null, $columns = array(), $filter = array(), $orderBy = array(), $range = null)
{
import('classes.statistics.StatisticsHelper');
$statsHelper = new StatisticsHelper();
// Check the parameter format.
if (!(is_array($filter) && is_array($orderBy))) {
return null;
}
// Check whether which context we are.
$context = $statsHelper->getContext($filter);
// Identify and canonicalize filtered metric types.
$defaultSiteMetricType = $this->getDefaultMetricType();
$siteMetricTypes = $this->getMetricTypes();
$metricType = $statsHelper->canonicalizeMetricTypes($metricType, $context, $defaultSiteMetricType, $siteMetricTypes);
if (!is_array($metricType)) {
return null;
}
$metricTypeCount = count($metricType);
// Canonicalize columns.
if (is_scalar($columns)) {
$columns = array($columns);
}
// The metric type dimension is not additive. This imposes two important
// restrictions on valid report descriptions:
// 1) We need at least one metric Type to be specified.
if ($metricTypeCount === 0) {
return null;
}
// 2) If we have multiple metrics then we have to force inclusion of
// the metric type column to avoid aggregation over several metric types.
if ($metricTypeCount > 1) {
if (!in_array(STATISTICS_DIMENSION_METRIC_TYPE, $columns)) {
array_push($columns, STATISTICS_DIMENSION_METRIC_TYPE);
}
}
// Retrieve report plugins.
if (is_a($context, 'Context')) {
$contextId = $context->getId();
} else {
$contextId = CONTEXT_SITE;
}
$reportPlugins = PluginRegistry::loadCategory('reports', true, $contextId);
if (!is_array($reportPlugins)) {
return null;
}
// Run through all report plugins and try to retrieve the requested metrics.
$report = array();
foreach ($reportPlugins as $reportPlugin) {
// Check whether one (or more) of the selected metrics can be
// provided by this plugin.
$availableMetrics = $reportPlugin->getMetricTypes();
$availableMetrics = array_intersect($availableMetrics, $metricType);
if (count($availableMetrics) == 0) {
continue;
}
// Retrieve a (partial) report.
$partialReport = $reportPlugin->getMetrics($availableMetrics, $columns, $filter, $orderBy, $range);
// Merge the partial report with the main report.
$report = array_merge($report, $partialReport);
// Remove the found metric types from the metric type array.
$metricType = array_diff($metricType, $availableMetrics);
}
// Check whether we found all requested metric types.
if (count($metricType) > 0) {
return null;
}
// Return the report.
return $report;
}