protected function onModelCreated()
    {
        parent::onModelCreated();

        if ($this->incomingRestModel instanceof Model){
            $this->setRestModel($this->incomingRestModel);
        } elseif ($this->incomingRestModel instanceof Collection){
            $this->setRestCollection($this->incomingRestModel);
        }

        $this->model->createSubLeafFromNameEvent->attachHandler(function($leafName){

            if (!$this->hasRestModelOrCollection) {
                return null;
            }

            $restModel = $this->model->restModel;

            if ($restModel) {
                $class = $restModel->getModelName();
                $schema = $restModel->getSchema();
            } else {
                $restCollection = $this->model->restCollection;

                $class = $restCollection->getModelClassName();
                $schema = $restCollection->getModelSchema();
            }

            $leaf = $this->createLeafForLeafName($leafName);

            if ($leaf){
                return $leaf;
            }

            // See if the model has a relationship with this name.
            $relationships = SolutionSchema::getAllOneToOneRelationshipsForModelBySourceColumnName($class);

            $columnRelationships = false;

            if (isset($relationships[$leafName])) {
                $columnRelationships = $relationships[$leafName];
            } else {
                if ($leafName == $schema->uniqueIdentifierColumnName) {
                    if (isset($relationships[""])) {
                        $columnRelationships = $relationships[""];
                    }
                }
            }

            if ($columnRelationships) {
                $relationship = $relationships[$leafName];

                $collection = $relationship->getCollection();

                $dropDown = new DropDown($leafName);
                $dropDown->setSelectionItems(
                    [
                        ["", "Please Select"],
                        $collection
                    ]
                );

                $dropDown->setLabel(StringTools::wordifyStringByUpperCase($relationship->getNavigationPropertyName()));

                return $dropDown;
            }

            $columns = $schema->getColumns();

            if (!isset($columns[$leafName])) {
                return null;
            }

            $column = $columns[$leafName];

            return $this->createLeafFromColumn($column, $leafName);
        });
    }