SyncRule: do not allow to sync unless some...

...properties have been defined.

fixes #383

application/views/scripts/syncrule/index.phtml

@@ -4,6 +4,16 @@
 </div>
 
 <div class="content">
+<?php if (! $rule->hasSyncProperties()): ?>
+<p class="warning">
+<?= sprintf(
+    $this->translate('You need must define some %s before you can run this Sync rule'),
+    $this->qlink('Sync Properties', 'director/syncrule/property', array('rule_id' => $rule->id))
+)
+?>
+</p>
+</div>
+<?php return; endif ?>
 <?php if (! $this->run): ?>
 <p class="warning">
 <?= $this->translate('This Sync Rule has never been run before.') ?>

library/Director/Objects/SyncRule.php

@@ -345,6 +345,12 @@ class SyncRule extends DbObject
         return $this->hasCombinedKey;
     }
 
+    public function hasSyncProperties()
+    {
+        $properties = $this->getSyncProperties();
+        return ! empty($properties);
+    }
+
     public function getSyncProperties()
     {
         if (! $this->hasBeenLoadedFromDb()) {