DK2/src/util/router.php

92 lines
2.8 KiB
PHP

<?php
class Router
{
private array $routes = [];
/**
* Add a route to the route tree. The route must be a URI path, and contain dynamic segments
* using a colon prefix. (:id, :slug, etc)
*
* Example:
* `$r->add($routes, 'GET', '/posts/:id', function($id) { echo "Viewing post $id"; });`
*/
public function add(string $method, string $route, callable $handler): Router
{
// Expand the route into segments and make dynamic segments into a common placeholder
$segments = array_map(function($segment) {
return str_starts_with($segment, ':') ? ':x' : $segment;
}, explode('/', trim($route, '/')));
// Push each segment into the routes array as a node, except if this is the root node
$node = &$this->routes;
foreach ($segments as $segment) {
// skip an empty segment, which allows us to register handlers for the root node
if ($segment === '') continue;
$node = &$node[$segment]; // build the node tree as we go
}
// Add the handler to the last node
$node[$method] = $handler;
return $this;
}
/**
* Perform a lookup in the route tree for a given method and URI. Returns an array with a result code,
* a handler if found, and any dynamic parameters. Codes are 200 for success, 404 for not found, and
* 405 for method not allowed.
*
* @return array ['code', 'handler', 'params']
*/
public function lookup(string $method, string $uri): array
{
// node is a reference to our current location in the node tree
$node = $this->routes;
// params will hold any dynamic segments we find
$params = [];
// if the URI is just a slash, we can return the handler for the root node
if ($uri === '/') {
return isset($node[$method])
? ['code' => 200, 'handler' => $node[$method], 'params' => null]
: ['code' => 405, 'handler' => null, 'params' => null];
}
// We'll split up the URI into segments and traverse the node tree
foreach (explode('/', trim($uri, '/')) as $segment) {
// if there is a node for this segment, move to it
if (isset($node[$segment])) {
$node = $node[$segment];
continue;
}
// if there is a dynamic segment, move to it and store the value
if (isset($node[':x'])) {
$params[] = $segment;
$node = $node[':x'];
continue;
}
// if we can't find a node for this segment, return 404
return ['code' => 404, 'handler' => null, 'params' => []];
}
// if we found a handler for the method, return it and any params. if not, return a 405
return isset($node[$method])
? ['code' => 200, 'handler' => $node[$method], 'params' => $params ?? []]
: ['code' => 405, 'handler' => null, 'params' => []];
}
public function get(string $route, callable $handler): Router
{
return $this->add('GET', $route, $handler);
}
public function post(string $route, callable $handler): Router
{
return $this->add('POST', $route, $handler);
}
}