Ticket Task count

This commit adds a ticket queue decoration for tasks count as well as option
to export same.

include/class.queue.php

@@ -618,6 +618,7 @@ function getExportableFields() {
                 'thread_count' =>   __('Thread Count'),
                 'reopen_count' =>   __('Reopen Count'),
                 'attachment_count' => __('Attachment Count'),
+                'task_count' => __('Task Count'),
                 ) + $cdata;
 
         return $fields;
@@ -1715,6 +1716,35 @@ function isVisible($row) {
     }
 }
 
+class TicketTasksCount
+extends QueueColumnAnnotation {
+    static $icon = 'list-ol';
+    static $qname = '_task_count';
+    static $desc = /* @trans */ 'Tasks Count';
+
+    function annotate($query, $name=false) {
+        $name = $name ?: static::$qname;
+        return $query->annotate(array(
+            $name => Task::objects()
+            ->filter(array('ticket__ticket_id' => new SqlField('ticket_id', 1)))
+            ->aggregate(array('count' => SqlAggregate::COUNT('id')))
+        ));
+    }
+
+    function getDecoration($row, $text) {
+        $count = $row[static::$qname];
+        if ($count) {
+            return sprintf(
+                '<small class="faded-more"><i class="icon-%s"></i> %s</small>',
+                static::$icon, $count);
+        }
+    }
+
+    function isVisible($row) {
+        return $row[static::$qname];
+    }
+}
+
 class ThreadCollaboratorCount
 extends QueueColumnAnnotation {
     static $icon = 'group';

include/class.search.php

@@ -1783,6 +1783,17 @@ function from_query($row, $name=false) {
     }
 }
 
+class TicketTasksCountField extends NumericField {
+
+    function addToQuery($query, $name=false) {
+        return TicketTasksCount::addToQuery($query, $name);
+    }
+
+    function from_query($row, $name=false) {
+         return TicketTasksCount::from_query($row, $name);
+    }
+}
+
 interface Searchable {
     // Fetch an array of [ orm__path => Field() ] pairs. The field label is
     // used when this list is rendered in a dropdown, and the field search

include/class.ticket.php

@@ -2327,6 +2327,9 @@ static function getSearchableFields() {
             'collaborator_count' => new ThreadCollaboratorCountField(array(
                         'label' => __('Collaborator Count'),
             )),
+            'task_count' => new TicketTasksCountField(array(
+                        'label' => __('Task Count'),
+            )),
             'reopen_count' => new TicketReopenCountField(array(
                         'label' => __('Reopen Count'),
             )),