1: <?php namespace Laravel\Database\Eloquent\Relationships;
  2: 
  3: class Belongs_To extends Relationship {
  4: 
  5:     /**
  6:      * Get the properly hydrated results for the relationship.
  7:      *
  8:      * @return Model
  9:      */
 10:     public function results()
 11:     {
 12:         return parent::first();
 13:     }
 14: 
 15:     /**
 16:      * Update the parent model of the relationship.
 17:      *
 18:      * @param  Model|array  $attributes
 19:      * @return int
 20:      */
 21:     public function update($attributes)
 22:     {
 23:         $attributes = ($attributes instanceof Model) ? $attributes->get_dirty() : $attributes;
 24: 
 25:         return $this->model->update($this->foreign_value(), $attributes);
 26:     }
 27: 
 28:     /**
 29:      * Set the proper constraints on the relationship table.
 30:      *
 31:      * @return void
 32:      */
 33:     protected function constrain()
 34:     {
 35:         $this->table->where($this->model->key(), '=', $this->foreign_value());
 36:     }
 37: 
 38:     /**
 39:      * Initialize a relationship on an array of parent models.
 40:      *
 41:      * @param  array   $parents
 42:      * @param  string  $relationship
 43:      * @return void
 44:      */
 45:     public function initialize(&$parents, $relationship)
 46:     {
 47:         foreach ($parents as &$parent)
 48:         {
 49:             $parent->relationships[$relationship] = null;
 50:         }
 51:     }
 52: 
 53:     /**
 54:      * Set the proper constraints on the relationship table for an eager load.
 55:      *
 56:      * @param  array  $results
 57:      * @return void
 58:      */
 59:     public function eagerly_constrain($results)
 60:     {
 61:         $keys = array();
 62: 
 63:         // Inverse one-to-many relationships require us to gather the keys from the
 64:         // parent models and use those keys when setting the constraint since we
 65:         // are looking for the parent of a child model in this relationship.
 66:         foreach ($results as $result)
 67:         {
 68:             if ( ! is_null($key = $result->{$this->foreign_key()}))
 69:             {
 70:                 $keys[] = $key;
 71:             }
 72:         }
 73: 
 74:         if (count($keys) == 0) $keys = array(0);
 75: 
 76:         $this->table->where_in($this->model->key(), array_unique($keys));
 77:     }
 78: 
 79:     /**
 80:      * Match eagerly loaded child models to their parent models.
 81:      *
 82:      * @param  array  $children
 83:      * @param  array  $parents
 84:      * @return void
 85:      */
 86:     public function match($relationship, &$children, $parents)
 87:     {
 88:         $foreign = $this->foreign_key();
 89: 
 90:         $dictionary = array();
 91: 
 92:         foreach ($parents as $parent)
 93:         {
 94:             $dictionary[$parent->get_key()] = $parent;
 95:         }
 96: 
 97:         foreach ($children as $child)
 98:         {
 99:             if (array_key_exists($child->$foreign, $dictionary))
100:             {
101:                 $child->relationships[$relationship] = $dictionary[$child->$foreign];
102:             }
103:         }
104:     }
105: 
106:     /**
107:      * Get the value of the foreign key from the base model.
108:      *
109:      * @return mixed
110:      */
111:     public function foreign_value()
112:     {
113:         return $this->base->{$this->foreign};
114:     }
115:     
116:     /**
117:     * Bind an object over a belongs-to relation using its id.
118:     *
119:     * @return Eloquent
120:     */
121:     
122:     public function bind($id)
123:     {
124:         $this->base->fill(array($this->foreign => $id))->save();
125: 
126:         return $this->base;
127:     }
128: 
129: }
130: