Zend Framework Form Factory

Factory.php

<?php

// application/forms/Factory.php

class Default_Form_Factory {
    
    /**
     * Acts as a registry for loaded forms
     * @var array
     */
    private static $_forms = array();
    
    /**
     * Instantiate a form based on class name and module
     *
     * Usage:
     * Default_Form_User class: Default_Form_Factory::create('user');
     * Account_Form_User class: Default_Form_Factory::create('user', 'account');
     * 
     * @param string $form
     * @param string $module
     * @param mixed $options
     * @return Zend_Form
     */
    public static function createForm($form, $module = 'Default', $options = null) {
        $formClass = self::_formClassName($form, $module);
        if (array_key_exists($formClass, self::$_forms)) {
            return self::$_forms[$formClass];
        }
        $formInstance = new $formClass($options);        
        if ($formInstance instanceof Zend_Form) {
            self::$_forms[$formClass] = $formInstance;
            return $formInstance;
        }
        return new Zend_Form();
    }
    
    /**
     * Set a custom form instance based on class name and module
     *
     * Usage:
     * Default_Form_User class: Default_Form_Factory::setForm($form, 'user');
     * Account_Form_User class: Default_Form_Factory::setForm($form, 'user', 'account');
     *
     * @param Zend_Form $instance
     * @param string $form
     * @param string $module
     */
    public static function setForm($instance, $form, $module = 'Default') {
        $formClass = self::_formClassName($form, $module);
        self::$_forms[$formClass] = $instance;
    }

    /**
     * Clear all loaded forms
     */
    public static function reset() {
        self::$_forms[$formClass] = array();
    }

    /**
     * Build the form class name from the form name and module
     *
     * @param string $form
     * @param string $module
     * @return string
     */
    private static function _formClassName($form, $module) {
        return ucfirst($module) . '_Form_' . ucfirst($form);
    }
}