Call to a member function on a non-object

Question

I'm working through Practical Web 2.0 Appications currently and have hit a bit of a roadblock. I'm trying to get PHP, MySQL, Apache, Smarty and the Zend Framework all working correctly so I can begin to build the application. I have gotten the bootstrap file for Zend working, shown here:

<?php
    require_once('Zend/Loader.php');
    Zend_Loader::registerAutoload();

    // load the application configuration
    $config = new Zend_Config_Ini('../settings.ini', 'development');
    Zend_Registry::set('config', $config);


    // create the application logger
    $logger = new Zend_Log(new Zend_Log_Writer_Stream($config->logging->file));
    Zend_Registry::set('logger', $logger);


    // connect to the database
    $params = array('host'     => $config->database->hostname,
                    'username' => $config->database->username,
                    'password' => $config->database->password,
                    'dbname'   => $config->database->database);

    $db = Zend_Db::factory($config->database->type, $params);
    Zend_Registry::set('db', $db);


    // handle the user request
    $controller = Zend_Controller_Front::getInstance();
    $controller->setControllerDirectory($config->paths->base .
                                        '/include/Controllers');

    // setup the view renderer
    $vr = new Zend_Controller_Action_Helper_ViewRenderer();
    $vr->setView(new Templater());
    $vr->setViewSuffix('tpl');
    Zend_Controller_Action_HelperBroker::addHelper($vr);

    $controller->dispatch();
?>

This calls the IndexController. The error comes with the use of this Templater.php to implement Smarty with Zend:

<?php
    class Templater extends Zend_View_Abstract
    {
        protected $_path;
        protected $_engine;

        public function __construct()
        {
            $config = Zend_Registry::get('config');

            require_once('Smarty/Smarty.class.php');

            $this->_engine = new Smarty();
            $this->_engine->template_dir = $config->paths->templates;
            $this->_engine->compile_dir = sprintf('%s/tmp/templates_c',
                                                  $config->paths->data);

            $this->_engine->plugins_dir = array($config->paths->base .
                                                '/include/Templater/plugins',
                                                'plugins');
        }

        public function getEngine()
        {
            return $this->_engine;
        }

        public function __set($key, $val)
        {
            $this->_engine->assign($key, $val);
        }

        public function __get($key)
        {
            return $this->_engine->get_template_vars($key);
        }

        public function __isset($key)
        {
            return $this->_engine->get_template_vars($key) !== null;
        }

        public function __unset($key)
        {
            $this->_engine->clear_assign($key);
        }

        public function assign($spec, $value = null)
        {
            if (is_array($spec)) {
                $this->_engine->assign($spec);
                return;
            }

            $this->_engine->assign($spec, $value);
        }

        public function clearVars()
        {
            $this->_engine->clear_all_assign();
        }

        public function render($name)
        {
            return $this->_engine->fetch(strtolower($name));
        }

        public function _run()
        { }
    }
?>

The error I am getting when I load the page is this:

Fatal error: Call to a member function fetch() on a non-object in /var/www/phpweb20/include/Templater.php on line 60

I understand it doesn't see $name as an object, but I don't know how to go about fixing this. Isn't the controller supposed to refer to the index.tpl? I haven't been able to discover what the $name variable represents and how to fix this to get the foundation working.

Any help you have is much appreciated!

Answer 1

The problem isn't with the $name variable but rather with the $_engine variable. It's currently empty. You need to verify that the path specification to Smarty.class.php is correct.

You might try this to begin your debugging:

$this->_engine = new Smarty();
print_r($this->_engine);

If it turns out that $_engine is correct at that stage then verify that it is still correctly populated within the render() function.

Answer 2

Zend has an example of creating a templating system which implements the Zend_View_Interface here: http://framework.zend.com/manual/en/zend.view.scripts.html#zend.view.scripts.templates.interface

That might save you some time from trying to debug a custom solution.

Answer 3

removing the __construct method, from the class, solved the similar issue I was facing.

Answer 4

Renaming __construct() to Tempater() worked for me.