Yaf零基础学习总结14-Yaf内建类之Yaf_View_Interface

Yaf给用户提供一个了一个可扩展的、可自定的视图引擎接口，就是Yaf_View_Interface，并且Yaf还内置实现了一个简单的模板引擎Yaf_View_Simple，它只支持只支持PHP脚本。所以我们一般都会用自己的视图引擎（比如Smarty）来代替Yaf内置的Yaf_View_Simple。

下面我们以Smarty试图引擎为例来如何实现Yaf的视图接口，Yaf_View_Interface。实现接口之前我们先看下Yaf_View_Interface需要实现的所有成员方法

Yaf_View_Interface {
/* 方法 */
abstract public bool assign ( string $name [, string $value ] )
abstract public bool display ( string $tpl [, array $tpl_vars ] )
abstract public void getScriptPath ( void )
abstract public string render ( string $tpl [, array $tpl_vars ] )
abstract public void setScriptPath ( string $template_dir )
}

//所以我们一定要实现以上5个方法，以下是代码实例

_smarty = new Smarty;

        if (null !== $tmplPath) {
            $this->setScriptPath($tmplPath);
        }

        foreach ($extraParams as $key => $value) {
            $this->_smarty->$key = $value;
        }
    }

    /**
     * Set the path to the templates
     *
     * @param string $path The directory to set as the path.
     * @return void
     */
    public function setScriptPath($path)
    {
        if (is_readable($path)) {
            $this->_smarty->template_dir = $path;
            return;
        }

        throw new Exception('Invalid path provided');
    }

    /**
     * Assign a variable to the template
     *
     * @param string $key The variable name.
     * @param mixed $val The variable value.
     * @return void
     */
    public function __set($key, $val)
    {
        $this->_smarty->assign($key, $val);
    }

    /**
     * Allows testing with empty() and isset() to work
     *
     * @param string $key
     * @return boolean
     */
    public function __isset($key)
    {
        return (null !== $this->_smarty->get_template_vars($key));
    }

    /**
     * Allows unset() on object properties to work
     *
     * @param string $key
     * @return void
     */
    public function __unset($key)
    {
        $this->_smarty->clear_assign($key);
    }

    /**
     * Assign variables to the template
     *
     * Allows setting a specific key to the specified value, OR passing
     * an array of key => value pairs to set en masse.
     *
     * @see __set()
     * @param string|array $spec The assignment strategy to use (key or
     * array of key => value pairs)
     * @param mixed $value (Optional) If assigning a named variable,
     * use this as the value.
     * @return void
     */
    public function assign($spec, $value = null) {
        if (is_array($spec)) {
            $this->_smarty->assign($spec);
            return;
        }

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

    /**
     * Clear all assigned variables
     *
     * Clears all variables assigned to Yaf_View either via
     * {@link assign()} or property overloading
     * ({@link __get()}/{@link __set()}).
     *
     * @return void
     */
    public function clearVars() {
        $this->_smarty->clear_all_assign();
    }

    /**
     * Processes a template and returns the output.
     *
     * @param string $name The template to process.
     * @return string The output.
     */
    public function render($name, $value = NULL) {
        return $this->_smarty->fetch($name);
    }

    public function display($name, $value = NULL) {
        echo $this->_smarty->fetch($name);
    }

}
?>

//实现之后我们可以在Bootstrap中注册我们的smarty模板引擎了

getConfig();
        Yaf_Registry::set("config", $config);
    }

    public function _initLocalName() {
        /** 将Smarty_Adapter注册为本地类哭 */
        Yaf_Loader::getInstance()->registerLocalNamespace('Smarty');
    }

    public function _initSmarty(Yaf_Dispatcher $dispatcher) {
        $smarty = new Smarty_Adapter(null, Yaf_Registry::get("config")->get("smarty"));
        $dispatcher->setView($smarty);
        /* 设置smarty为我们的模板引擎 */
    }
}
?>