Issue #2943952 by andileco: Enable stacking

includes/charts.pages.inc

@@ -283,6 +283,15 @@ function charts_settings_form($form, $defaults = [], $field_options = [], $paren
     }
   }
 
+  // Enable stacking.
+  $form['grouping'] = [
+    '#type' => 'checkbox',
+    '#title' => t('Stacking'),
+    '#description' => t('Enable stacking'),
+    '#default_value' => $options['grouping'],
+    '#weight' => '-19',
+  ];
+
   if ($field_options) {
     $first_field = key($field_options);
 

modules/charts_blocks/src/Plugin/Block/ChartsBlock.php

@@ -110,6 +110,7 @@ class ChartsBlock extends BlockBase {
       '#weight' => '-16',
     ];
     // Enable stacking.
+    unset($form['grouping']['#parents']);
     $form['grouping'] = [
       '#type' => 'checkbox',
       '#title' => $this->t('Stacking'),

modules/charts_c3/src/Plugin/chart/C3.php

@@ -136,10 +136,20 @@ class C3 extends AbstractChart {
     }
     $chartData->types = $types;
 
+
     if ($options['type'] != 'pie' && $options['type'] != 'donut') {
       $c3->setAxis($chartAxis);
     }
 
+    // Determines if chart is stacked.
+    if (!empty($options['grouping'] && $options['grouping'] == TRUE)) {
+      $seriesNames = [];
+      for ($i = 0; $i < count($seriesData); $i++) {
+        array_push($seriesNames, $seriesData[$i]['name']);
+      }
+      $chartData->setGroups([$seriesNames]);
+    }
+
     $chartColor = new ChartColor();
     $seriesColors = [];
     for ($i = 0; $i < count($seriesData); $i++) {

modules/charts_c3/src/Settings/CThree/ChartData.php

@@ -11,11 +11,12 @@ class ChartData implements \JsonSerializable {
   private $type;
   private $labels = TRUE;
   private $x = 'x';
+  private $groups = '';
 
   /**
    * Get X.
    *
-   * @return array
+   * @return mixed
    *   X.
    */
   public function getX() {
@@ -92,6 +93,26 @@ class ChartData implements \JsonSerializable {
     $this->labels = $labels;
   }
 
+  /**
+   * Get Stacking.
+   *
+   * @return array
+   *   Stacking.
+   */
+  public function getGroups() {
+    return $this->groups;
+  }
+
+  /**
+   * Set Stacking.
+   *
+   * @param array $groups
+   *   Stacking.
+   */
+  public function setGroups($groups) {
+    $this->groups = $groups;
+  }
+
   /**
    * Json Serialize.
    *

src/Form/ChartsConfigForm.php

@@ -269,6 +269,16 @@ class ChartsConfigForm extends ConfigFormBase {
       }
     }
 
+    // Enable stacking.
+    $form['grouping'] = [
+      '#type'          => 'checkbox',
+      '#title'         => $this->t('Stacking'),
+      '#description'   => $this->t('Enable stacking'),
+      '#default_value' => $options['grouping'],
+      '#weight'        => '-15',
+      '#parents'       => array_merge($parents, ['grouping']),
+    ];
+
     $form['display'] = [
       '#title'       => $this->t('Display'),
       '#type'        => 'details',

src/Plugin/views/style/ChartsPluginStyleChart.php

@@ -66,7 +66,7 @@ class ChartsPluginStyleChart extends StylePluginBase {
     // Limit grouping options (we only support one grouping field).
     if (isset($form['grouping'][0])) {
       $form['grouping'][0]['field']['#title'] = t('Grouping field');
-      $form['grouping'][0]['field']['#description'] = t('If grouping by a particular field, that field will be used to determine stacking of the chart. Generally this will be the same field as what you select for the "Label field" below. If you do not have more than one "Provides data" field below, there will be nothing to stack. If you want to have another series displayed, use a "Chart attachment" display, and set it to attach to this display. Stacking is still a work in progress for C3 Charts.');
+      $form['grouping'][0]['field']['#description'] = t('If grouping by a particular field, that field will be used to determine stacking of the chart. Generally this will be the same field as what you select for the "Label field" below. If you do not have more than one "Provides data" field below, there will be nothing to stack. If you want to have another series displayed, use a "Chart attachment" display, and set it to attach to this display.');
       $form['grouping'][0]['field']['#attributes']['class'][] = 'charts-grouping-field';
       // Grouping by rendered version has no effect in charts. Hide the options.
       $form['grouping'][0]['rendered']['#access'] = FALSE;