Add an example to demonstrate the table grouping preprocessor.

modules/d3_sankey_examples/d3_sankey_examples.module

@@ -36,6 +36,21 @@ function d3_sankey_examples_menu() {
     'weight' => -1,
   ) + $items['d3/examples/sankey'];
 
+  // Uses d3_sankey_table_group_pp to create a Sankey chart.
+  if (module_exists('d3_sankey_table_group_pp')) {
+    $items['d3/examples/sankey/table_group_preprocess'] = array(
+      'title' => 'Table grouping preprocessor',
+      'description' => 'Creates a Sankey chart using a preprocessor that links values in the same row, grouping duplicates.',
+      // For consistency with d3_examples, this has no access restriction (i.e.:
+      // an open page callback). Note that in this module's implementation of
+      // hook_requirements() (in d3_sankey_examples.install), we remind users to
+      // disable this module on the live site.
+      'access callback' => TRUE,
+      'page callback' => '_d3_sankey_examples_table_group_pp',
+      'type' => MENU_LOCAL_TASK,
+    );
+  }
+
   return $items;
 }
 
@@ -174,3 +189,51 @@ function _d3_sankey_examples_sankey() {
 
   return d3_draw($chart);
 }
+
+/**
+ * Menu callback: Uses d3_sankey_table_group_pp to create a Sankey chart.
+ */
+function _d3_sankey_examples_table_group_pp() {
+  $chart = array(
+    'type' => 'sankey',
+
+    // See _d3_sankey_examples_sankey() for an explanation of these properties.
+    'id' => 'visualization',
+    'sankeyType' => D3_SANKEY_SANKEYTYPE_PATH,
+    'width' => '700',
+    'height' => '400',
+    'nodeWidth' => 24,
+    'nodePadding' => 8,
+    'spread' => TRUE,
+    'iterations' => 1,
+    'alignLabel' => D3_SANKEY_ALIGNLABEL_AUTO,
+  );
+
+  // Create some sample data.
+  $unprocessed_data = array(
+    array('1970s', 'Drama', 'The Godfather'),
+    array('1970s', 'Sci-fi/Fantasy', 'Star Wars'),
+    array('1980s', 'Sci-fi/Fantasy', 'The Empire Strikes Back'),
+    array('1990s', 'Drama', 'The Shawshank Redemption'),
+    array('1990s', 'Biography', "Schindler's List"),
+    array('2000s', 'Action', 'The Dark Knight'),
+    array('2000s', 'Sci-fi/Fantasy', 'LotR: Return of the King'),
+  );
+
+  // Initialize a GroupingPreprocessor.
+  $preprocessor = new \Drupal\d3_sankey_table_group_pp\TableGroupingPreprocessor();
+
+  // Feed the preprocessor the sample data.
+  foreach ($unprocessed_data as $row) {
+    $preprocessor->ingestRow($row);
+  }
+
+  // Get an object containing the raw chart data out of the preprocessor.
+  $raw_data = $preprocessor->getRawData();
+
+  // Add the nodes and links to the chart.
+  $chart['nodes'] = $raw_data->getAssocArrayNodes();
+  $chart['links'] = $raw_data->getAssocArrayLinks();
+
+  return d3_draw($chart);
+}