Allow passing in a model instance to relationship insert / update methods.

laravel/database/eloquent/relationships/belongs_to.php

@@ -15,11 +15,13 @@ class Belongs_To extends Relationship {
 	/**
 	 * Update the parent model of the relationship.
 	 *
-	 * @param  array  $attributes
+	 * @param  Model|array  $attributes
 	 * @return int
 	 */
 	public function update($attributes)
 	{
+		$attributes = ($attributes instanceof Model) ? $attributes->get_dirty() : $attributes;
+
 		return $this->model->update($this->foreign_value(), $attributes);
 	}
 

laravel/database/eloquent/relationships/has_many_and_belongs_to.php

@@ -79,7 +79,7 @@ class Has_Many_And_Belongs_To extends Relationship {
 	 * @param  array  $joining
 	 * @return bool
 	 */
-	public function add($id, $attributes = array())
+	public function attach($id, $attributes = array())
 	{
 		$joining = array_merge($this->join_record($id), $attributes);
 
@@ -89,12 +89,20 @@ class Has_Many_And_Belongs_To extends Relationship {
 	/**
 	 * Insert a new record for the association.
 	 *
-	 * @param  array  $attributes
-	 * @param  array  $joining
+	 * @param  Model|array  $attributes
+	 * @param  array        $joining
 	 * @return bool
 	 */
 	public function insert($attributes, $joining = array())
 	{
+		// If the attributes are actually an instance of a model, we'll just grab the
+		// array of attributes off of the model for saving, allowing the developer
+		// to easily validate the joining models before inserting them.
+		if ($attributes instanceof Model)
+		{
+			$attributes = $attributes->attributes;
+		}
+
 		$model = $this->model->create($attributes);
 
 		// If the insert was successful, we'll insert a record into the joining table
@@ -139,9 +147,6 @@ class Has_Many_And_Belongs_To extends Relationship {
 	 */
 	protected function insert_joining($attributes)
 	{
-		// All joining tables get creation and update timestamps automatically even though
-		// some developers may not need them. This just provides them if necessary since
-		// it would be a pain for the developer to maintain them each manually.
 		$attributes['created_at'] = $this->model->get_timestamp();
 
 		$attributes['updated_at'] = $attributes['created_at'];

laravel/database/eloquent/relationships/has_one_or_many.php

@@ -7,11 +7,13 @@ class Has_One_Or_Many extends Relationship {
 	/**
 	 * Insert a new record for the association.
 	 *
-	 * @param  array  $attributes
+	 * @param  Model|array  $attributes
 	 * @return bool
 	 */
 	public function insert($attributes)
 	{
+		$attributes = ($attributes instanceof Model) ? $attributes->attributes : $attributes;
+
 		$attributes[$this->foreign_key()] = $this->base->get_key();
 
 		return $this->model->create($attributes);