Add TreeDropdownField from React to Entwine

src/Forms/TreeDropdownField.php

@@ -605,6 +605,26 @@ class TreeDropdownField extends FormField
         $callback = $this->getDisableFunction();
         return $callback && call_user_func($callback, $node);
     }
+    
+    /**
+     * Attributes to be given for this field type
+     * @return array
+     */
+    public function getAttributes()
+    {
+        $attributes = array(
+            'class' => $this->extraClass(),
+            'id' => $this->ID(),
+            'data-schema' => json_encode($this->getSchemaData()),
+            'data-state' => json_encode($this->getSchemaState()),
+        );
+        
+        $attributes = array_merge($attributes, $this->attributes);
+        
+        $this->extend('updateAttributes', $attributes);
+        
+        return $attributes;
+    }
 
     /**
      * @param string $field

templates/SilverStripe/Forms/TreeDropdownField.ss

@@ -1,8 +1,7 @@
-<div class="TreeDropdownField <% if $extraClass %> $extraClass<% end_if %><% if $ShowSearch %> searchable<% end_if %>"
-     data-url-tree="$Link('tree')"
-     data-title="$Title.ATT"
-     data-empty-title="$EmptyTitle.ATT"
-     <% if $Description %>title="$Description.ATT"<% end_if %>
-     <% if $Metadata %>data-metadata="$Metadata.ATT"<% end_if %> tabindex="0">
+<div
+	class="TreeDropdownField<% if $extraClass %> $extraClass<% end_if %><% if $ShowSearch %> searchable<% end_if %>"
+	$AttributesHTML('class')
+	<% if $Metadata %>data-metadata="$Metadata.ATT"<% end_if %>
+>
 	<input id="$ID" type="hidden" name="$Name.ATT" value="$Value.ATT" />
 </div>