php微框架 flight源码阅读——框架初始化、Loader、Dispatcher

在自动加载实现完成后，接着new flightEngine()实例化了下框架的核心类Engine，这个类翻译过来名字就是引擎发动机的意思，是flight的引擎发动机，很有想象力吧。public static function app() { static $initialized = false; if (!$initialized) { require_once DIR.’/autoload.php’; self::$engine = new \flight\Engine(); $initialized = true; } return self::$engine;}在实例化Engine这个类的时候，当前类的构造方法进行了对框架的初始化工作。public function __construct() { $this->vars = array(); $this->loader = new Loader(); $this->dispatcher = new Dispatcher(); $this->init();}接着来看init方法都做了什么，将初始化状态标记为静态变量static $initialized，判断如果为true，将$this->vars以及$this->loader、$this->dispatcher中保存的属性重置为默认状态。static $initialized = false;$self = $this;if ($initialized) { $this->vars = array(); $this->loader->reset(); $this->dispatcher->reset();} 接下来将框架的Request、Response、Router、View类的命定空间地址register（设置）到Loader类的classes属性中。// Register default components$this->loader->register(‘request’, ‘\flight\net\Request’);$this->loader->register(‘response’, ‘\flight\net\Response’);$this->loader->register(‘router’, ‘\flight\net\Router’);$this->loader->register(‘view’, ‘\flight\template\View’, array(), function($view) use ($self) { $view->path = $self->get(‘flight.views.path’); $view->extension = $self->get(‘flight.views.extension’);}); flight/core/Loader.phppublic function register($name, $class, array $params = array(), $callback = null) { unset($this->instances[$name]); $this->classes[$name] = array($class, $params, $callback);}再接下来就是将框架给用户提供的调用方法，设置到调度器Dispatcher类的events属性中。// Register framework methods$methods = array( ‘start’,‘stop’,‘route’,‘halt’,’error’,’notFound’, ‘render’,‘redirect’,’etag’,’lastModified’,‘json’,‘jsonp’);foreach ($methods as $name) { $this->dispatcher->set($name, array($this, ‘_’.$name));}flight/core/Dispatcher.php/** * Assigns a callback to an event. * * @param string $name Event name * @param callback $callback Callback function /public function set($name, $callback) { $this->events[$name] = $callback;}接下来呢，就是设置框架的一些配置，将这些配置保存在Engine类的vars属性中。// Default configuration settings$this->set(‘flight.base_url’, null);$this->set(‘flight.case_sensitive’, false);$this->set(‘flight.handle_errors’, true);$this->set(‘flight.log_errors’, false);$this->set(‘flight.views.path’, ‘./views’);$this->set(‘flight.views.extension’, ‘.php’);flight/Engine.php/* * Sets a variable. * * @param mixed $key Key * @param string $value Value /public function set($key, $value = null) { if (is_array($key) || is_object($key)) { foreach ($key as $k => $v) { $this->vars[$k] = $v; } } else { $this->vars[$key] = $value; }}最后一步的操作，当调用框架的start方法时，给其设置一些前置操作，通过set_error_handler()和set_exception_handler()设置用户自定义的错误和异常处理函数，如何使用自定义的错误和异常函数，可以看这两个范例:https://segmentfault.com/n/13…https://segmentfault.com/n/13…。// Startup configuration$this->before(‘start’, function() use ($self) { // Enable error handling if ($self->get(‘flight.handle_errors’)) { set_error_handler(array($self, ‘handleError’)); set_exception_handler(array($self, ‘handleException’)); } // Set case-sensitivity $self->router()->case_sensitive = $self->get(‘flight.case_sensitive’);});$initialized = true;/* * Custom error handler. Converts errors into exceptions. * * @param int $errno Error number * @param int $errstr Error string * @param int $errfile Error file name * @param int $errline Error file line number * @throws \ErrorException /public function handleError($errno, $errstr, $errfile, $errline) { if ($errno & error_reporting()) { throw new \ErrorException($errstr, $errno, 0, $errfile, $errline); }}/* * Custom exception handler. Logs exceptions. * * @param \Exception $e Thrown exception /public function handleException($e) { if ($this->get(‘flight.log_errors’)) { error_log($e->getMessage()); } $this->error($e);}在$this->before()操作中，会将前置操作设置到Dispatcher类的filters属性中。这些操作完成后，将$initialized = true。/* * Adds a pre-filter to a method. * * @param string $name Method name * @param callback $callback Callback function /public function before($name, $callback) { $this->dispatcher->hook($name, ‘before’, $callback);}flight/core/Dispatcher.php/* * Hooks a callback to an event. * * @param string $name Event name * @param string $type Filter type * @param callback $callback Callback function */public function hook($name, $type, $callback) { $this->filters[$name][$type][] = $callback;}