php - Dynamically build a class member variable -

i trying setup php (zend framework) project through injection dependence. far when instanciated model, pass table , view (database view) model that:

$table = new my_table(); $view = new my_view(); $model = new my_model($table, $view); 

all models extends same class take care of construction, message handling , getters forms interact model.

now have inject model model , looking passive static way of doing this. in model's parent class have added static method inject called in application bootstrap. pass 2 string in form of key => value key name of variable have created in model , value string represents class instanciated.

my_model::inject('dependentmodel', 'my_other_model') 

the issue arise when try use key new member variable through following code :

protected function _initdependency() {     $this->_table = null;      foreach (self::$_staticdependency $key => $dependency) {         $varname = '_' . $key;         $this->{$$varname} = new $dependency();     } } 

i following message

notice: undefined variable: _dependentmodel 

what best way achieve that, knowing want create models ignorants of dependencies?

use arrays

class foo {   private $_data = array();     protected function _initdependency()   {     $this->_table = null;      foreach (self::$_staticdependency $key => $dependency) {       $varname = '_' . $key;       $this->_data[$varname] = new $dependency();     }   } } 

(as side effect removes variable-variables)

you can use __get(), __set(), __isset() , __unset() simulate property-behaviour.