Patch for Drupal module 8 fullcalendar 2.x to allow configure short title in calendar view.

fullcalendar-short-title.patch

diff --git a/fullcalendar_view.theme.inc b/fullcalendar_view.theme.inc
index fe51c3a..cbc584b 100644
--- a/fullcalendar_view.theme.inc
+++ b/fullcalendar_view.theme.inc
@@ -244,6 +244,17 @@ function template_preprocess_views_view_fullcalendar(array &$variables) {
         else {
           $title = t('Invalid event title');
         }
+
+        // Event short title.
+        if (empty($options['short_title']) || $options['short_title'] == 'title') {
+          $short_title = $translated_entity->getTitle();
+        }
+        elseif ($current_entity->hasField($options['short_title'])) {
+          $short_title = $translated_entity->get($options['short_title'])->value;
+        }
+        else {
+          $short_title = t('Invalid event short title');
+        }
       }
       else {
         // Description for events. For multiple bundle types,
@@ -287,9 +298,21 @@ function template_preprocess_views_view_fullcalendar(array &$variables) {
         else {
           $title = t('Invalid event title');
         }
+
+        // Event short title.
+        if (empty($options['short_title']) || $options['short_title'] == 'title') {
+          $short_title = $fields['title']->advancedRender($row);
+        }
+        elseif (!empty($fields[$options['short_title']])) {
+          $short_title = $fields[$options['short_title']]->advancedRender($row);
+        }
+        else {
+          $short_title = t('Invalid event short title');
+        }
       }
       $entry = [
-        'title' =>  Xss::filterAdmin($title),
+        'title' =>  Xss::filterAdmin($short_title),
+        'regular_title' =>  Xss::filterAdmin($title),
         'description' => $des,
         'id' => $entity_id,
         'url' => $current_entity->toUrl('canonical', ['language' => $language])->toString(),
diff --git a/js/fullcalendar_view.js b/js/fullcalendar_view.js
index 6483df2..8dad064 100644
--- a/js/fullcalendar_view.js
+++ b/js/fullcalendar_view.js
@@ -37,11 +37,18 @@
             dayClick: dayClickCallback,
             eventRender: function(event, $el) {
               // Event title with HTML markup.
-              $el.find(".fc-title, .fc-list-item-title").html(event.title);
+              var calendar_view = $el.closest('.fc-view-container');
+              if (event.source.calendar.view.name == 'month' || event.source.calendar.view.name == 'agendaWeek') {
+                $el.find(".fc-title, .fc-list-item-title").html(event.title);
+              }
+              else {
+                $el.find(".fc-title, .fc-list-item-title").html(event.regular_title);
+              }
+
               // Popup tooltip.
               if (event.description) {
                 if ($el.fullCalendarTooltip !== "undefined") {
-                  $el.fullCalendarTooltip(event.title, event.description);
+                  $el.fullCalendarTooltip(event.regular_title, event.description);
                 }
               }
               // Recurring event.
diff --git a/src/Plugin/views/style/FullCalendarDisplay.php b/src/Plugin/views/style/FullCalendarDisplay.php
index d66691e..5a30dc0 100644
--- a/src/Plugin/views/style/FullCalendarDisplay.php
+++ b/src/Plugin/views/style/FullCalendarDisplay.php
@@ -72,6 +72,7 @@ class FullCalendarDisplay extends StylePluginBase {
     $options['end'] = ['default' => ''];
     $options['des'] = ['default' => ''];
     $options['title'] = ['default' => ''];
+    $options['short_title'] = ['default' => ''];
     $options['use_entity_fields'] = ['default' => TRUE];
     $options['business_start'] = ['default' => ''];
     $options['business_end'] = ['default' => ''];
@@ -160,6 +161,15 @@ class FullCalendarDisplay extends StylePluginBase {
       '#options' => $field_names,
       '#default_value' => (!empty($this->options['title'])) ? $this->options['title'] : '',
     ];
+
+    // Field name of short_title.
+    $form['short_title'] = [
+      '#title' => $this->t('Short Title Field'),
+      '#type' => 'select',
+      '#options' => $field_names,
+      '#default_value' => (!empty($this->options['short_title'])) ? $this->options['short_title'] : '',
+    ];
+
     // Field for description.
     $form['des'] = [
       '#title' => $this->t('Description Field'),