do not allow to overwrite constructor

core/ViewDataTable/Visualization.php

@@ -36,7 +36,7 @@ abstract class Visualization extends View
      */
     protected $viewDataTable;
 
-    public function __construct($view)
+    final public function __construct($view)
     {
         $templateFile = static::TEMPLATE_FILE;
 

plugins/CoreVisualizations/Visualizations/JqplotGraph/Bar.php

@@ -13,6 +13,7 @@ namespace Piwik\Plugins\CoreVisualizations\Visualizations\JqplotGraph;
 
 use Piwik\Plugins\CoreVisualizations\JqplotDataGenerator;
 use Piwik\Plugins\CoreVisualizations\Visualizations\JqplotGraph;
+use Piwik\Visualization\Config;
 
 /**
  * Visualization that renders HTML for a Bar graph using jqPlot.
@@ -21,10 +22,11 @@ class Bar extends JqplotGraph
 {
     const ID = 'graphVerticalBar';
 
-    public function __construct($view)
+    public function configureVisualization(Config $properties)
     {
-        parent::__construct($view);
-        $view->datatable_js_type = 'JqplotBarGraphDataTable';
+        parent::configureVisualization($properties);
+
+        $properties->datatable_js_type = 'JqplotBarGraphDataTable';
     }
 
     public static function getDefaultPropertyValues()

plugins/CoreVisualizations/Visualizations/JqplotGraph/Evolution.php

@@ -45,9 +45,7 @@ class Evolution extends JqplotGraph
     {
         parent::init();
 
-        $view = $this->viewDataTable;
-
-        $this->calculateEvolutionDateRange($view);
+        $this->calculateEvolutionDateRange($this->viewDataTable);
     }
 
     public function beforeLoadDataTable(Request $request, Config $properties)

plugins/CoreVisualizations/Visualizations/JqplotGraph/Pie.php

@@ -13,6 +13,8 @@ namespace Piwik\Plugins\CoreVisualizations\Visualizations\JqplotGraph;
 
 use Piwik\Plugins\CoreVisualizations\JqplotDataGenerator;
 use Piwik\Plugins\CoreVisualizations\Visualizations\JqplotGraph;
+use Piwik\Visualization\Config;
+use Piwik\Visualization\Request;
 
 /**
  * Visualization that renders HTML for a Pie graph using jqPlot.
@@ -21,9 +23,10 @@ class Pie extends JqplotGraph
 {
     const ID = 'graphPie';
 
-    public function __construct($view)
+    public function init()
     {
-        parent::__construct($view);
+        parent::init();
+
         $view->visualization_properties->show_all_ticks = true;
         $view->datatable_js_type = 'JqplotPieGraphDataTable';
 
@@ -37,6 +40,28 @@ class Pie extends JqplotGraph
         };
     }
 
+    public function configureVisualization(Config $properties)
+    {
+        parent::configureVisualization($properties);
+
+        $properties->visualization_properties->show_all_ticks = true;
+        $properties->datatable_js_type = 'JqplotPieGraphDataTable';
+    }
+
+    public function afterAllFilteresAreApplied($dataTable, Config $properties, Request $request)
+    {
+        parent::afterAllFilteresAreApplied($dataTable, $properties, $request);
+
+        $metricColumn = reset($properties->columns_to_display);
+
+        if ($metricColumn == 'label') {
+            $metricColumn = next($properties->columns_to_display);
+        }
+
+        $properties->columns_to_display = array($metricColumn ? : 'nb_visits');
+    }
+
+
     public static function getDefaultPropertyValues()
     {
         $result = parent::getDefaultPropertyValues();