Route using either a prefix or a domain

I am working on a platform that allows users to run their own site in either a sub folder of the main website domain, or map a custom domain for their site.

When using a custom domain the URL structure for each route is slightly different in that it is prefixed with the username, but when using a custom domain then this prefix is not used.

Is there a clever way to achieve this in my Route::group to handle both request types in one route and successfully use reverse routing to produce the appropriate URL based on the parameters passed to it.

Below is an example of using the prefix

Route::group(array( 'prefix' => 'sites/{username}'), function() {
    Route::get('/photos/{album_id}.html', array('uses' => 'Media\PhotosController@album_view', 'as' => 'photo_album'));
});

And here is an example of using a custom domain

Route::group(array('domain' => '{users_domain}'), function() {
    Route::get('/photos/{album_id}.html', array('uses' => 'Media\PhotosController@album_view', 'as' => 'photo_album'));
});

Ideally I would like to be in a position where I could use either

route('photo_album', ['username' => 'johnboy', 'album_id' => 123] )

and be returned

http://www.mainwebsitedomain.com/sites/johnboy/photos/123.html

or call the same route with different parameters

route('photo_album', ['users_domain' => 'www.johnboy.com', 'album_id' => 123] )

and be returned

http://www.johnboy.com/photos/123.html

This is a pretty tricky question so expect a few not so perfect workarounds in my answer...

I recommend you read everything first and try it out afterwards. This answer includes several simplification steps but I wrote down whole process to help with understanding

The first problem here is that you can't have multiple routes with the same name if you want to call them by name.

Let's fix that by adding a "route name prefix":

Route::group(array( 'prefix' => 'sites/{username}'), function() {
    Route::get('/photos/{album_id}.html', array('uses' => 'Media\PhotosController@album_view',
                                                'as' => 'photo_album'));
});

Route::group(array('domain' => '{users_domain}'), function() {
    Route::get('/photos/{album_id}.html', array('uses' => 'Media\PhotosController@album_view',
                                                'as' => 'domain.photo_album'));
});

So now we can use this to generate urls:

route('photo_album', ['username' => 'johnboy', 'album_id' => 123] )
route('domain.photo_album', ['users_domain' => 'www.johnboy.com', 'album_id' => 123])

(No worries we will get rid of domain. in the URL generation later...)

The next problem is that Laravel doesn't allow a full wildcard domain like 'domain' => '{users_domain}'. It works fine for generating URLs but if you try to actually access it you get a 404. What's the solution for this you ask? You have to create an additional group that listens to the domain you're currently on. But only if it isn't the root domain of your site.

For simplicity reasons let's first add the application domain to your config. I suggest this in config/app.php:

'domain' => env('APP_DOMAIN', 'www.mainwebsitedomain.com')

This way it is also configurable via the environment file for development.

After that we can add this conditional route group:

$currentDomain = Request::server('HTTP_HOST');
if($currentDomain != config('app.domain')){
    Route::group(array('domain' => $currentDomain), function() {
        Route::get('/photos/{album_id}.html', array('uses' => 'Media\PhotosController@album_view',
                                                    'as' => 'current_domain.photo_album'));
    });
}

Soooo... we got our routes. However this is pretty messy, even with just one single route. To reduce the code duplication your can move the actual routes to one (or more) external files. Like this:

app/Http/routes/photos.php:

if(!empty($routeNamePrefix)){
    $routeNamePrefix = $routeNamePrefix . '.';
}
else {
    $routeNamePrefix = '';
}

Route::get('/photos/{album_id}.html', ['uses' => 'Media\PhotosController@album_view',
                                            'as' => $routeNamePrefix.'photo_album']);

And then the new routes.php:

// routes for application domain routes
Route::group(['domain' => config('app.domain'), 'prefix' => 'sites/{username}'], function($group){
    include __DIR__.'/routes/photos.php';
});

// routes to LISTEN to custom domain requests
$currentDomain = Request::server('HTTP_HOST');
if($currentDomain != config('app.domain')){
    Route::group(['domain' => $currentDomain], function(){
        $routeNamePrefix = 'current_domain';
        include __DIR__.'/routes/photos.php';
    });
}

// routes to GENERATE custom domain URLs
Route::group(['domain' => '{users_domain}'], function(){
    $routeNamePrefix = 'domain';
    include __DIR__.'/routes/photos.php';
});

Now the only thing missing is a custom URL generation function. Unfortunately Laravel's route() won't be able to handle this logic so you have to override it. Create a file with custom helper functions, for example app/helpers.php and require it in bootstrap/autoload.php before vendor/autoload.php is loaded:

require __DIR__.'/../app/helpers.php';

require __DIR__.'/../vendor/autoload.php';

Then add this function to the helpers.php:

function route($name, $parameters = array(), $absolute = true, $route = null){
    $currentDomain = Request::server('HTTP_HOST');
    $usersDomain = array_get($parameters, 'users_domain');
    if($usersDomain){
        if($currentDomain == $usersDomain){
            $name = 'current_domain.'.$name;
            array_forget($parameters, 'users_domain');
        }
        else {
            $name = 'domain.'.$name;
        }
    }
    return app('url')->route($name, $parameters, $absolute, $route);
}

You can call this function exactly like you asked for and it will behave like the normal route() in terms of options and passing parameters.