lithium\net\http\Route

Extends lithium\core\Object

class

The Route class represents a single URL pattern which is matched against incoming requests, in order to determine the correct controller and action that an HTTP request should be dispatched to.

Typically, Route objects are created and handled through the Router class, as follows. When connecting a route, a Route object is instantiated behind the scenes, and added to the Router's collection.

Router::connect("/{:controller}/{:action}");

This following matches a set of parameters against all Route objects contained in Router, and if a match is found, returns a string URL with parameters inserted into the URL pattern.

Router::match(array("controller" => "users", "action" => "login")); // returns "/users/login"

For more advanced routing, however, you can directly instantiate a Route object, a subclass, or any class that implements parse() and match() (see the documentation for each individual method) and configure it manually -- if, for example, you want the route to match different incoming URLs than it generates.

$route = new Route(array(
       'template' => '/users/{:user}',
       'pattern' => '@^/u(?:sers)?(?:/(?P<user>[^\/]+))$@',
       'params' => array('controller' => 'users', 'action' => 'index'),
       'match' => array('controller' => 'users', 'action' => 'index'),
       'defaults' => array('controller' => 'users'),
       'keys' => array('user' => 'user'),
       'options' => array('compile' => false, 'wrap' => false)
));

Router::connect($route); // this will match '/users/<username>' or '/u/<username>'.

Source

class Route extends \lithium\core\Object {

	/**
	 * The URL template string that the route matches, i.e.
	 * `'/admin/{:controller}/{:id:\d+}/{:args}'`.
	 *
	 * This string can contain any combination of...
	 *
	 * 1. fixed elements, i.e. `'/admin'`
	 * 2. plain capture elements, i.e. `'/{:controller}'`
	 * 3. capture elements paired with regular expressions, i.e. `'/{:id:\d+}'`
	 * 4. capture elements paired with named regular expression patterns, `'/{:id:ID}'`
	 * 5. the speciall wildcard capture element `'{:args}'`
	 *
	 * @var string
	 */
	protected $_template = '';

	/**
	 * The regular expression used to match URLs.
	 *
	 * This regular expression is typically _compiled_ down from the higher-level syntax used in
	 * `$_template`, but can be set manually with compilation turned off in the constructor for
	 * extra control or if you are using pre-compiled `Route` objects.
	 *
	 * @var string
	 * @see lithium\net\http\Route::$_template
	 * @see lithium\net\http\Route::__construct()
	 */
	protected $_pattern = '';

	/**
	 * An array of route parameter names (i.e. `{:foo}`) that appear in the URL template.
	 *
	 * @var array
	 * @see lithium\net\http\Route::$_template
	 */
	protected $_keys = array();

	/**
	 * An array of key/value pairs representing the parameters of the route. For keys which match
	 * parameters present in the route template, the corresponding values match the default values
	 * of those parameters. Specifying a default value for a template parameter makes that
	 * parameter optional. Any other pairs specified must match exactly when doing a reverse lookup
	 * in order for the route to match.
	 *
	 * @var array
	 */
	protected $_params = array();

	/**
	 * The array of values that appear in the second parameter of `Router::connect()`, which are
	 * **not** present in the URL template. When matching a route, these parameters must appear
	 * **exactly** as specified here.
	 *
	 * @var array
	 */
	protected $_match = array();

	/**
	 * An array of metadata parameters which must be present in the request in order for the route
	 * to match.
	 *
	 * @var array
	 */
	protected $_meta = array();

	/**
	 * The default values for the keys present in the URL template.
	 *
	 * @var array
	 * @see lithium\net\http\Route::$_template
	 * @see lithium\net\http\Route::$_keys
	 */
	protected $_defaults = array();

	/**
	 * An array of regular expression patterns used in route matching.
	 *
	 * @var array
	 */
	protected $_subPatterns = array();

	/**
	 * An array of parameter names which will persist by default when generating URLs. By default,
	 * the `'controller'` parameter is set to persist, which means that the controller name matched
	 * for a given request will be used to generate all URLs for that request, unless the
	 * `'controller'` parameter is specified in that URL with another value.
	 *
	 * @var array
	 */
	protected $_persist = array();

	/**
	 * Contains a function which will be executed if this route is matched. The function takes the
	 * instance of the associated `Request` object, and the array of matched route parameters, and
	 * must return either the parameters array (which may be modified by the handler) or a
	 * `Response` object, in which case the response will be returned directly. This may be used to
	 * handle redirects, or simple API services.
	 *
	 * ```
	 * new Route(array(
	 *     'template' => '/photos/{:id:[0-9]+}.jpg',
	 *     'handler' => function($request) {
	 *         return new Response(array(
	 *             'headers' => array('Content-type' => 'image/jpeg'),
	 *             'body' => Photos::first($request->id)->bytes()
	 *         ));
	 *     }
	 * });
	 * ```
	 *
	 * @see lithium\net\http\Route::parse()
	 * @see lithium\net\http\Response
	 * @var callable
	 */
	protected $_handler = null;

	/**
	 * Array of closures used to format route parameters when compiling URLs.
	 *
	 * @see lithium\net\http\Router::formatters()
	 * @var array
	 */
	protected $_formatters = array();

	/**
	 * Auto configuration properties. Also used as the list of properties to return when exporting
	 * this `Route` object to an array.
	 *
	 * @see lithium\net\http\Route::export()
	 * @var array
	 */
	protected $_autoConfig = array(
		'template', 'pattern', 'params', 'match', 'meta',
		'keys', 'defaults', 'subPatterns', 'persist', 'handler'
	);

	/**
	 * Constructor.
	 *
	 * @param array $config Available configuration options are:
	 *         - `'params'` _array_
	 *         - `'template'` _string_
	 *         - `'pattern'` _string_
	 *         - `'match'` _array_
	 *         - `'meta'` _array_
	 *         - `'defaults'` _array_
	 *         - `'keys'` _array_
	 *         - `'persist'` _array_
	 *         - `'handler'` _callable_
	 *         - `'continue'` _boolean_
	 *         - `'modifiers'` _array_
	 *         - `'formatters'` _array_
	 *         - `'unicode'` _boolean_
	 * @return void
	 */
	public function __construct(array $config = array()) {
		$defaults = array(
			'params'   => array(),
			'template' => '/',
			'pattern'  => '',
			'match'    => array(),
			'meta'     => array(),
			'defaults' => array(),
			'keys'     => array(),
			'persist'  => array(),
			'handler'  => null,
			'continue' => false,
			'modifiers' => array(),
			'formatters' => array(),
			'unicode'  => true
		);
		parent::__construct($config + $defaults);
	}

	protected function _init() {
		parent::_init();

		if (!$this->_config['continue'] && !preg_match('@{:action:.*?}@', $this->_template)) {
			$this->_params += array('action' => 'index');
		}
		if (!$this->_pattern) {
			$this->compile();
		}
		if (isset($this->_keys['controller']) || isset($this->_params['controller'])) {
			$this->_persist = $this->_persist ?: array('controller');
		}
	}

	/**
	 * Attempts to parse a request object and determine its execution details.
	 *
	 * @see lithium\net\http\Request
	 * @see lithium\net\http\Request::$params
	 * @see lithium\net\http\Route::$_handler
	 * @param \lithium\net\http\Request $request A request object containing the details of
	 *        the request to be routed.
	 * @param array $options Used to determine the operation of the method, and override certain
	 *              values in the `Request` object:
	 *              - `'url'` _string_: If present, will be used to match in place of the `$url`
	 *                 property of `$request`.
	 * @return object|boolean If this route matches `$request`, returns the request with
	 *         execution details attached to it (inside `Request::$params`). Alternatively when
	 *         a route handler function was used, returns the result of its invocation. Returns
	 *         `false` if the route never matched.
	 */
	public function parse($request, array $options = array()) {
		$defaults = array('url' => $request->url);
		$options += $defaults;
		$url = '/' . trim($options['url'], '/');
		$pattern = $this->_pattern;

		if (!preg_match($pattern, $url, $match)) {
			return false;
		}
		foreach ($this->_meta as $key => $compare) {
			$value = $request->get($key);

			if (!($compare == $value || (is_array($compare) && in_array($value, $compare)))) {
				return false;
			}
		}
		foreach ($this->_config['modifiers'] as $key => $modifier) {
			if (isset($match[$key])) {
				$match[$key] = $modifier($match[$key]);
			}
		}

		$result = array_intersect_key($match + array('args' => array()), $this->_keys);
		foreach ($result as $key => $value) {
			if ($value === '') {
				unset($result[$key]);
			}
		}
		$result += $this->_params + $this->_defaults;
		$request->params = $result + (array) $request->params;
		$request->persist = array_unique(array_merge($request->persist, $this->_persist));

		if ($this->_handler) {
			$handler = $this->_handler;
			return $handler($request);
		}
		return $request;
	}

	/**
	 * Matches a set of parameters against the route, and returns a URL string
	 * if the route matches the parameters.
	 *
	 * @param array $options An array of parameters.
	 * @return string|boolean URL string on success, else `false` if the route didn't match.
	 */
	public function match(array $options = array()) {
		$defaults = array('action' => 'index', 'http:method' => 'GET');
		$query = null;

		if (!$this->_config['continue']) {
			$options += $defaults;

			if (isset($options['?'])) {
				$query = $options['?'];
				$query = '?' . (is_array($query) ? http_build_query($query) : $query);
				unset($options['?']);
			}
		}
		if (!$options = $this->_matchMethod($options)) {
			return false;
		}
		if (!$options = $this->_matchKeys($options)) {
			return false;
		}
		foreach ($options as $key => $value) {
			if (isset($this->_config['formatters'][$key])) {
				$options[$key] = $this->_config['formatters'][$key]($value);
			}
		}
		foreach ($this->_subPatterns as $key => $pattern) {
			if (isset($options[$key]) && !preg_match("/^{$pattern}$/", $options[$key])) {
				return false;
			}
		}
		$defaults = $this->_defaults + $defaults;

		if ($this->_config['continue']) {
			return $this->_write(array('args' => '{:args}') + $options, $this->_defaults);
		}
		return $this->_write($options, $defaults + array('args' => '')) . $query;
	}

	/**
	 * Returns a boolean value indicating whether this is a continuation route. If `true`, this
	 * route will allow incoming requests to "fall through" to other routes, aggregating parameters
	 * for both this route and any subsequent routes.
	 *
	 * @return boolean Returns the value of `$_config['continue']`.
	 */
	public function canContinue() {
		return $this->_config['continue'];
	}

	/**
	 * Helper used by `Route::match()` which check if the required http method is compatible
	 * with the route.
	 *
	 * @see lithium\net\http\Route::match()
	 * @param array $options An array of URL parameters.
	 * @return mixed On success, returns an updated array of options, On failure, returns `false`.
	 */
	protected function _matchMethod($options) {
		$isMatch = (
			!isset($this->_meta['http:method']) ||
			$options['http:method'] === $this->_meta['http:method']
		);
		if (!$isMatch) {
			return false;
		}
		unset($options['http:method']);
		return $options;
	}

	/**
	 * A helper method used by `match()` to verify that options required to match this route are
	 * present in a URL array.
	 *
	 * @see lithium\net\http\Route::match()
	 * @param array $options An array of URL parameters.
	 * @return mixed On success, returns an updated array of options, merged with defaults. On
	 *         failure, returns `false`.
	 */
	protected function _matchKeys($options) {
		$args = array('args' => 'args');

		$scope = array();
		if (!empty($options['scope'])) {
			$scope = (array) $options['scope'] + array('params' => array());
			$scope = array_flip($scope['params']);
		}
		unset($options['scope']);

		if (array_intersect_key($options, $this->_match) != $this->_match) {
			return false;
		}
		if ($this->_config['continue']) {
			if (array_intersect_key($this->_keys, $options + $args) != $this->_keys) {
				return false;
			}
		} else {
			if (array_diff_key($options, $this->_match + $this->_keys + $scope)) {
				return false;
			}
		}
		$options += $this->_defaults;
		$base = $this->_keys + $args;
		$match = array_intersect_key($this->_keys, $options) + $args;
		sort($base);
		sort($match);

		if ($base !== $match) {
			return false;
		}
		return $options;
	}

	/**
	 * Writes a set of URL options to this route's template string.
	 *
	 * @param array $options The options to write to this route, with defaults pre-merged.
	 * @param array $defaults The default template options for this route (contains hard-coded
	 *        default values).
	 * @return string Returns the route template string with option values inserted.
	 */
	protected function _write($options, $defaults) {
		$template = $this->_template;
		$trimmed = true;
		$options += array('args' => '');

		foreach (array_reverse($this->_keys, true) as $key) {
			$value =& $options[$key];
			$pattern = isset($this->_subPatterns[$key]) ? ":{$this->_subPatterns[$key]}" : '';
			$rpl = "{:{$key}{$pattern}}";
			$len = strlen($rpl) * -1;

			if ($trimmed && isset($defaults[$key]) && $value == $defaults[$key]) {
				if (substr($template, $len) == $rpl) {
					$template = rtrim(substr($template, 0, $len), '/');
					continue;
				}
			}
			if ($value === null) {
				$template = str_replace("/{$rpl}", '', $template);
				continue;
			}
			if ($key !== 'args') {
				$trimmed = false;
			}
			$template = str_replace($rpl, $value, $template);
		}
		return $template ?: '/';
	}

	/**
	 * Exports the properties that make up the route to an array, for debugging, caching or
	 * introspection purposes.
	 *
	 * @return array An array containing the properties of the route object, such as URL templates
	 *         and parameter lists.
	 */
	public function export() {
		$result = array();

		foreach ($this->_autoConfig as $key) {
			if ($key === 'formatters') {
				continue;
			}
			$result[$key] = $this->{'_' . $key};
		}
		return $result;
	}

	/**
	 * Compiles URL templates into regular expression patterns for matching against request URLs,
	 * and extracts template parameters into match-parameter arrays.
	 *
	 * @return void
	 */
	public function compile() {
		foreach ($this->_params as $key => $value) {
			if (!strpos($key, ':')) {
				continue;
			}
			unset($this->_params[$key]);
			$this->_meta[$key] = $value;
		}

		$this->_match = $this->_params;

		if ($this->_template === '/' || $this->_template === '') {
			$this->_pattern = '@^/*$@';
			return;
		}
		$this->_pattern = "@^{$this->_template}\$@";
		$match = '@([/.])?\{:([^:}]+):?((?:[^{]+?(?:\{[0-9,]+\})?)*?)\}@S';

		if ($this->_config['unicode']) {
			$this->_pattern .= 'u';
		}
		preg_match_all($match, $this->_pattern, $m);

		if (!$tokens = $m[0]) {
			return;
		}
		$slashes = $m[1];
		$params = $m[2];
		$regexs = $m[3];
		unset($m);
		$this->_keys = array();

		foreach ($params as $i => $param) {
			$this->_keys[$param] = $param;
			$this->_pattern = $this->_regex($regexs[$i], $param, $tokens[$i], $slashes[$i]);
		}
		$this->_defaults += array_intersect_key($this->_params, $this->_keys);
		$this->_match = array_diff_key($this->_params, $this->_defaults);
	}

	/**
	 * Generates a sub-expression capture group for a route regex, using an optional user-supplied
	 * matching pattern.
	 *
	 * @param string $regex An optional user-supplied match pattern. If a route is defined like
	 *               `"/{:id:\d+}"`, then the value will be `"\d+"`.
	 * @param string $param The parameter name which the capture group is assigned to, i.e.
	 *               `'controller'`, `'id'` or `'args'`.
	 * @param string $token The full token representing a matched element in a route template, i.e.
	 *               `'/{:action}'`, `'/{:path:js|css}'`, or `'.{:type}'`.
	 * @param string $prefix The prefix character that separates the parameter from the other
	 *               elements of the route. Usually `'.'` or `'/'`.
	 * @return string Returns the full route template, with the value of `$token` replaced with a
	 *         generated regex capture group.
	 */
	protected function _regex($regex, $param, $token, $prefix) {
		if ($regex) {
			$this->_subPatterns[$param] = $regex;
		} elseif ($param == 'args') {
			$regex = '.*';
		} else {
			$regex = '[^\/]+';
		}

		$req = $param === 'args' || array_key_exists($param, $this->_params) ? '?' : '';

		if ($prefix === '/') {
			$pattern = "(?:/(?P<{$param}>{$regex}){$req}){$req}";
		} elseif ($prefix === '.') {
			$pattern = "\\.(?P<{$param}>{$regex}){$req}";
		} else {
			$pattern = "(?P<{$param}>{$regex}){$req}";
		}
		return str_replace($token, $pattern, $this->_pattern);
	}
}

lithium\net\http\Route

Related

Source