update Piwik to version 2.16 (fixes #91)

www/analytics/plugins/Actions/Columns/Metrics/ExitRate.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+namespace Piwik\Plugins\Actions\Columns\Metrics;
+
+use Piwik\DataTable\Row;
+use Piwik\Metrics\Formatter;
+use Piwik\Piwik;
+use Piwik\Plugin\ProcessedMetric;
+
+/**
+ * Percent of visits that finished on this page. Calculated as:
+ *
+ *     exit_nb_visits / nb_visits
+ *
+ * exit_nb_visits & nb_visits are calculated by the Actions archiver.
+ */
+class ExitRate extends ProcessedMetric
+{
+    public function getName()
+    {
+        return 'exit_rate';
+    }
+
+    public function getTranslatedName()
+    {
+        return Piwik::translate('General_ColumnExitRate');
+    }
+
+    public function compute(Row $row)
+    {
+        $exitVisits = $this->getMetric($row, 'exit_nb_visits');
+        $visits = $this->getMetric($row, 'nb_visits');
+
+        return Piwik::getQuotientSafe($exitVisits, $visits, $precision = 2);
+    }
+
+    public function format($value, Formatter $formatter)
+    {
+        return $formatter->getPrettyPercentFromQuotient($value);
+    }
+
+    public function getDependentMetrics()
+    {
+        return array('exit_nb_visits', 'nb_visits');
+    }
+}