Using RegEx to match URL routes - regex

Question

I'm building a PHP Framework for conclusion of my course, and I've stuck on a solution for match some custom routes and standard routes.
My framework's route are similar at routes of Zend Framework 1.
It's match standard routes for
/module/controller/action/param/value/param2/value2/paramn/valuen
The part of URI are optional, and the / route leads to application module, index controller and index action without params and values.
I'm stuck in some custom routes, that I define this way:
/blog/:postname/
/admin/logout/
/blog/posts/:year/:category/
/about/
That routes must match this examples URI requests.
/blog/my-first-post/
/blog/my-first-post/referenced/facebook/
/admin/logout/
/admin/logout/session-id/246753/action
/blog/posts/2013/turism/
/blog/posts/2013/turism/page/2/
But not had to match the standard routes. The custom routes must precede the standard routes.
Some examples of standard routes. Examples:
/
/application/
/application/index/
/application/index/index/
/blog/posts/view/id/3/
/admin/login/
/admin/login/logout (that one are the
/admin/blog/posts/edit/id/3/
/admin/blog/posts/edit/id/3/success/false/
The way I find to do this ellegantily is using RegEx for the matches, but I've trying to learn RegEx for more than one month and don't got it all.
PS: After match the current route, I must to bind the :variable with the related position in the REQUEST_URI.
Thank you for help.

Answer 1

While admittedly tempting, I wouldn't go with regex in this particular case. Even though I usually go that way. A simple loop and match would do, unless your course is setting some restrictions you have to follow.
I put together an example that should get the job done and runs in the console, just to show what i mean.
function get_route($uri){
$routes = [
'blog#show' => 'blog/:postname',
'admin#logout' => 'admin/logout',
'blog#category' => 'blog/posts/:year/:category',
'home#about' => 'about'
];
$params = [];
$uri = preg_replace('/#|\?.+/', '', $uri); // remove hash or query strings
$uri = preg_replace('/(^\/)?(\/$)?/', '', $uri); // trim slashes
$uri = explode('/', $uri);
$action = null;
foreach ($routes as $this_action => $this_route) { // loop through possible routes
$fractions = explode('/', $this_route);
if (sizeof($fractions) !== sizeof($uri)) continue; // did not match length of uri
for ($i=0; $i<sizeof($uri); $i++) { // compare each part of uri to each part of route
if (substr($fractions[$i], 0, 1) !== ':' && $fractions[$i] !== $uri[$i]) break; // not a match and not a param
if ($i === sizeof($uri)-1) { // made it to the last fraction!
$ii = 0;
foreach ($fractions as $fraction) {
if (substr($fraction, 0, 1) == ':') { // it's a param, map it!
$params[substr($fraction,1)] = $uri[$ii];
}
$ii++;
}
return ['action'=>$this_action, 'params'=>$params];
}
}
}
return false;
}

Answer 2

I could reach my needs with this code, a lot of tests has passed.
public function matchCustomRoute($uri)
{
if($uri == '')
{
return null;
}
$customRoutes = $this->getRoutes();
$explodeUri = explode('/', $uri);
$arrayUri = array();
foreach($explodeUri as $uriPart)
{
if($uriPart == '')
{
continue;
}
$arrayUri[] = $uriPart;
}
$countUri = count($arrayUri);
foreach($customRoutes as $key => $value)
{
$explodeRoute = explode('/',$value['route']);
$arrayRoute = array();
foreach($explodeRoute as $routePart)
{
if($routePart == '')
{
continue;
}
$arrayRoute[] = $routePart;
}
$countRoute = count($arrayRoute);
if($countRoute > $countUri)
{
continue;
}
$matches = 0;
for($i = 0 ; $i < $countRoute ; $i++)
{
$match = preg_match('/'.$arrayUri[$i].'/', '/'.$arrayRoute[$i].'/');
if($match == 0)
{
if(substr($arrayRoute[$i], 0, 1) == ':')
{
$value['params'][substr($arrayRoute[$i], 1)] = $arrayUri[$i];
}
else
{
continue;
}
}
$matches++;
}
if($matches == $countRoute)
{
return $value;
}
}
return null;
}
Thank you for help.