PHP框架之简单的路由器

小云云原创: 2017-11-13 13:41:294836浏览

路由的功能就是分发请求到不同的控制器，基于的原理就是正则匹配。接下来呢，我们实现一个简单的路由器，实现的能力是对于静态的路由（没占位符的），正确调用callback。

对于有占位符的路由，正确调用callback时传入占位符参数，譬如对于路由：/user/{id}，当请求为/user/23时，传入参数$args结构为

[    &#39;id&#39; => &#39;23&#39;
]

大致思路

我们需要把每个路由的信息管理起来：http方法（$method），路由字符串（$route），回调（$callback），因此需要一个addRoute方法，另外提供短方法get，post（就是把$method写好）

对于/user/{id}这样的有占位符的路由字符串，把占位符要提取出来，然后占位符部分变成正则字符串

实现

Route.php类

<?phpnamespace SalamanderRoute;class Route {    /** @var string */
    public $httpMethod;    /** @var string */
    public $regex;    /** @var array */
    public $variables;    /** @var mixed */
    public $handler;    /**
     * Constructs a route (value object).
     *
     * @param string $httpMethod
     * @param mixed  $handler
     * @param string $regex
     * @param array  $variables
     */
    public function __construct($httpMethod, $handler, $regex, $variables) {        $this->httpMethod = $httpMethod;        $this->handler = $handler;      
      $this->regex = $regex;        $this->variables = $variables;
    }    /**
     * Tests whether this route matches the given string.
     *
     * @param string $str
     *
     * @return bool
     */
    public function matches($str) {
        $regex = &#39;~^&#39; . $this->regex . &#39;$~&#39;;        return (bool) preg_match($regex, $str);
    }
}

Dispatcher.php

<?php/**
 * User: salamander
 * Date: 2017/11/12
 * Time: 13:43
 */namespace SalamanderRoute;class Dispatcher {    /** @var mixed[][] */
    protected $staticRoutes = [];    /** @var Route[][] */
    private $methodToRegexToRoutesMap = [];    const NOT_FOUND = 0;    const FOUND = 1;    const METHOD_NOT_ALLOWED = 2;    /**
     * 提取占位符
     * @param $route
     * @return array
     */
    private function parse($route) {
        $regex = &#39;~^(?:/[a-zA-Z0-9_]*|/\{([a-zA-Z0-9_]+?)\})+/?$~&#39;;        if(preg_match($regex, $route, $matches)) {            // 去掉full match
            array_shift($matches);            return [
                preg_replace(&#39;~{[a-zA-Z0-9_]+?}~&#39;, &#39;([a-zA-Z0-9_]+)&#39;, $route),
                $matches,
            ];
        }        throw new \LogicException(&#39;register route failed, pattern is illegal&#39;);
    }    /**
     * 注册路由
     * @param $httpMethod string | string[]
     * @param $route
     * @param $handler
     */
    public function addRoute($httpMethod, $route, $handler) {
        $routeData = $this->parse($route);        foreach ((array) $httpMethod as $method) {            if ($this->isStaticRoute($routeData)) {                $this->addStaticRoute($httpMethod, $routeData, $handler);
            } else {                $this->addVariableRoute($httpMethod, $routeData, $handler);
            }
        }
    }    private function isStaticRoute($routeData) {        return count($routeData[1]) === 0;
    }    private function addStaticRoute($httpMethod, $routeData, $handler) {
        $routeStr = $routeData[0];        if (isset($this->staticRoutes[$httpMethod][$routeStr])) {            throw new \LogicException(sprintf(                &#39;Cannot register two routes matching "%s" for method "%s"&#39;,
                $routeStr, $httpMethod
            ));
        }        if (isset($this->methodToRegexToRoutesMap[$httpMethod])) {            foreach ($this->methodToRegexToRoutesMap[$httpMethod] as $route) {                if ($route->matches($routeStr)) {                    throw new \LogicException(sprintf(                        &#39;Static route "%s" is shadowed by previously defined variable route "%s" for method "%s"&#39;,
                        $routeStr, $route->regex, $httpMethod
                    ));
                }
            }
        }        $this->staticRoutes[$httpMethod][$routeStr] = $handler;
    }    private function addVariableRoute($httpMethod, $routeData, $handler) {        list($regex, $variables) = $routeData;        if (isset($this->methodToRegexToRoutesMap[$httpMethod][$regex])) {            throw new \LogicException(sprintf(                &#39;Cannot register two routes matching "%s" for method "%s"&#39;,
                $regex, $httpMethod
            ));
        }        $this->methodToRegexToRoutesMap[$httpMethod][$regex] = new Route(
            $httpMethod, $handler, $regex, $variables
        );
    }    public function get($route, $handler) {        $this->addRoute(&#39;GET&#39;, $route, $handler);
    }    public function post($route, $handler) {        $this->addRoute(&#39;POST&#39;, $route, $handler);
    }    public function put($route, $handler) {        $this->addRoute(&#39;PUT&#39;, $route, $handler);
    }    public function delete($route, $handler) {        $this->addRoute(&#39;DELETE&#39;, $route, $handler);
    }    public function patch($route, $handler) {        $this->addRoute(&#39;PATCH&#39;, $route, $handler);
    }    public function head($route, $handler) {        $this->addRoute(&#39;HEAD&#39;, $route, $handler);
    }    /**
     * 分发
     * @param $httpMethod
     * @param $uri
     */
    public function dispatch($httpMethod, $uri) {
        $staticRoutes = array_keys($this->staticRoutes[$httpMethod]);        foreach ($staticRoutes as $staticRoute) {            if($staticRoute === $uri) {                return [self::FOUND, $this->staticRoutes[$httpMethod][$staticRoute], []];
            }
        }

        $routeLookup = [];
        $index = 1;
        $regexes = array_keys($this->methodToRegexToRoutesMap[$httpMethod]);        foreach ($regexes as $regex) {
            $routeLookup[$index] = [                $this->methodToRegexToRoutesMap[$httpMethod][$regex]->handler,                $this->methodToRegexToRoutesMap[$httpMethod][$regex]->variables,
            ];
            $index += count($this->methodToRegexToRoutesMap[$httpMethod][$regex]->variables);
        }
        $regexCombined = &#39;~^(?:&#39; . implode(&#39;|&#39;, $regexes) . &#39;)$~&#39;;        if(!preg_match($regexCombined, $uri, $matches)) {            return [self::NOT_FOUND];
        }        for ($i = 1; &#39;&#39; === $matches[$i]; ++$i);        list($handler, $varNames) = $routeLookup[$i];
        $vars = [];        foreach ($varNames as $varName) {
            $vars[$varName] = $matches[$i++];
        }        return [self::FOUND, $handler, $vars];
    }
}

配置

nginx.conf重写到index.php

location / {        try_files $uri $uri/ /index.php$is_args$args;        # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000 
       #        location ~ \.php$ {            fastcgi_pass   127.0.0.1:9000;            fastcgi_index  index.php;        
           fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;            include        fastcgi_params;        }    }
composer.json自动载入
{    "name": "salmander/route",    "require": {},    "autoload": {      "psr-4": 
{        "SalamanderRoute\\": "SalamanderRoute/"      } 
 }}

composer.json自动载入

{    "name": "salmander/route",    "require": {},    "autoload": {      "psr-4": 
{        "SalamanderRoute\\": "SalamanderRoute/"      }  }

最终使用

index.php

<?phpinclude_once &#39;vendor/autoload.php&#39;;use SalamanderRoute\Dispatcher;
$dispatcher = new Dispatcher();
$dispatcher->get(&#39;/&#39;, function () {    echo &#39;hello world&#39;;
});
$dispatcher->get(&#39;/user/{id}&#39;, function ($args) {    echo "user {$args[&#39;id&#39;]} visit";
});// Fetch method and URI from somewhere$httpMethod = $_SERVER[&#39;REQUEST_METHOD&#39;];
$uri = $_SERVER[&#39;REQUEST_URI&#39;];// 去掉查询字符串if (false !== $pos = strpos($uri, &#39;?&#39;)) {
    $uri = substr($uri, 0, $pos);
}
$routeInfo = $dispatcher->dispatch($httpMethod, $uri);switch ($routeInfo[0]) {    case Dispatcher::NOT_FOUND:        echo &#39;404 not found&#39;;        break;    case Dispatcher::FOUND:
        $handler = $routeInfo[1];
        $vars = $routeInfo[2];
        $handler($vars);        break;
}

看了上面的这个案例大家应该对PHP实现简单路由器，有更清楚的认识吧，后期我们还会继续推出相关文章，大家有任何问题都可以踊跃发言，