Provide a way to map views fields to a certain meaning

Don't we need ta mechanism to add some kind of filtering on the fields?
For example I know we only use real date fields in fullcalendar when we search for a date field.

Yeah i have seen a lot of similar plugins, like many slideshow/image related ones, so i would vote to introduce such a feature.

+++ b/lib/Drupal/views/Plugin/views/style/Mapping.phpundefined
@@ -0,0 +1,108 @@
+class Mapping extends StylePluginBase {

Can you explain how to use that without an actual subclass? So it seems to make sense to remove the @Plugin() and make the class abstract

+++ b/lib/Drupal/views/Plugin/views/style/Mapping.phpundefined
@@ -0,0 +1,108 @@
+      if ($optional = !empty($mapping[$key]['optional'])) {
+        $field_options = array('' => t('- None -'));

It seems to be that you want to have the default as optional, so what about using a 'required' here instead?

+++ b/lib/Drupal/views/Plugin/views/style/Mapping.phpundefined
@@ -0,0 +1,108 @@
+      $form['views_field_mappings'][$key] = array(

What about removing the views_ prefix here, this seems kind of redundant.

Looks good but the indentation for yaml file changed. 2 spaces it is now :)

The 2 spaces aren't really a big issue, but yeah it should be better corrected but hey if you don't want to do it, this is a good novice issue.

+++ b/lib/Drupal/views/Tests/Plugin/StyleTestBase.phpundefined
@@ -0,0 +1,43 @@
+   * Stores a view output in the elements.
+   */
+  function storeViewPreview($output) {

Let's clean up things like that later.

+++ b/lib/Drupal/views/Tests/Plugin/StyleUnformattedTest.phpundefined
@@ -29,25 +20,6 @@ public static function getInfo() {
-  protected function setUp() {
-    parent::setUp();
-
-    $this->enableViewsTestModule();
-  }
-
-  /**
-   * Stores a view output in the elements.
-   */
-  function storeViewPreview($output) {
-    $htmlDom = new DOMDocument();
-    @$htmlDom->loadHTML($output);
-    if ($htmlDom) {
-      // It's much easier to work with simplexml than DOM, luckily enough
-      // we can just simply import our DOM tree.
-      $this->elements = simplexml_import_dom($htmlDom);
-    }

Good redunction of the code.

+++ b/tests/views_test_data/lib/Drupal/views_test_data/Plugin/views/style/MappingTest.phpundefined
@@ -0,0 +1,70 @@
+  protected function allowNumericFields(&$fields) {

Maybe filterNumericFields could be better name

+++ b/plugins/views_plugin_style_mapping.incundefined
@@ -0,0 +1,127 @@
+  protected function define_mapping() {

I'm wondering whether it would make sense to mark this as abstract so it is required to implement.

Committed to 7.x-3.x

Perfect! Let's see what the tests tells us on d7.

hehe, it's green and go!