Routing

The router is responsible for everything about URLs so that you no longer have to think about them. We will show:

  • how to set up the router so that the URLs look like you want
  • a few notes about SEO redirection
  • and we'll show you how to write your own router

More human URLs (or cool or pretty URLs) are more usable, more memorable, and contribute positively to SEO. Nette Framework keeps this in mind and fully meets developers' desires.

Let's start a little technically. A router is an object that implements the Nette\Routing\Router interface, which can decompose a URL into an array of parameters (method match) and, conversely, build a URL from an array of parameters (method constructUrl). Therefore, it is also said that the router is bidirectional. Nette brings a very elegant way to define how the URLs of your application look like.

The router plays an important role in Nette Application. Thanks to router, it will find out which presenter and action to run. And it also uses the router to generate URLs in the template, for example:

<a n:href="Product:detail $productId">detail produktu</a>

The router compiles the resulting URL from these parameters. Read more in the chapter creating links.

However, the router is not limited to this use, you can use it in the same way in completely different cases, for the REST API, for applications where presenters are not used at all, etc. More in the section separated usage.

Thus, routing is a separate and sophisticated layer of the application, thanks to which the look of URL addresses can be easily designed or changed when the entire application is ready, because it can be done without modification of the code or templates. Which gives developers huge freedom.

Route Collection

The most pleasant way to define the URL addresses in the application is via the class Nette\Routing\RouteList, resp. her descendant Nette\Application\Routers\RouteList, which, in addition to the parent, adds support for presenters, which suits us. The big advantage is that the whole router is defined in one place and is not so scattered in the form of annotations in all presenters.

The definition consists of a list of so-called routes, ie masks of URL addresses and their associated presenters and actions using a simple API. We do not have to name the routes.

$router = new Nette\Application\Routers\RouteList;
$router->addRoute('rss.xml', 'Feed:rss');
$router->addRoute('article/<id>', 'Article:view');
...

The example says that if we open https://any-domain.com/rss.xml in the browser, the presenter Feed with the action rss will be displayed, etc. If no suitable route is found, Nette Application responds by throwing an exception BadRequestException, which appears to the user as a 404 Not Found error page.

In Nette 2.x, $router[] = new Route(...) was used instead of $router->addRoute(...).

Order of routes is important because they are tried sequentially from the first one to the last one. Basic rule is to declare routes from the most specific to the most general.

In order to connect the our router into the application, we must tell the DI container about it. The easiest way is to prepare the factory that will build the router object and tell the container configuration file to use it. So let's say we write a method for this purpose App\Router\RouterFactory::createRouter():

namespace App\Router;

use Nette\Application\Routers\RouteList;

class RouterFactory
{
	public static function createRouter(): RouteList
	{
		$router = new RouteList;
		$router->addRoute(...);
		return $router;
	}
}

Then we write in configuration file:

services:
	router: App\Router\RouterFactory::createRouter

Any dependencies, such as a database connection etc., are passed to the factory method as its parameters using autowiring:

public static function createRouter(Nette\Database\Connection $db): RouteList
{
	...
}

Mask and Parameters

The mask describes the relative path based on the site root. The simplest mask is a static URL:

$router->addRoute('products', 'Products:default');

Often masks contain so-called parameters. They are enclosed in angle brackets (e.g. <year>) and are passed to the target presenter, for example to the renderShow(int $year) method or to persistent parameter $year:

$router->addRoute('chronicle/<year>', 'History:show');

The example says that if we open https://any-domain.com/chronicle/2020 in the browser, the presenter History and the action show with parameter year => 2020 will be displayed.

We can specify a default value for the parameters directly in the mask and thus it becomes optional:

$router->addRoute('chronicle/<year=2020>', 'History:show');

The route will now accept the URL https://any-domain.com/chronicle/, which will again display History:show with parameter year => 2020.

Of course, the name of the presenter and the action can also be a parameter. For example:

$router->addRoute('<presenter>/<action>', 'Homepage:default');

This route accepts, for example, a URL in the form /article/edit resp. /catalog/list and translates them to presenters and actions Article:edit resp. Catalog:list.

It also gives to parameters presenter and action default values ​​Homepage and default and therefore they are optional. So the route also accepts a URL /article and translates it as Article:default. Or vice versa, a link to Product:default generates a path /product, a link to the default Homepage:default generates a path /.

The mask can describe not only the relative path based on the site root, but also the absolute path when it begins with a slash, or even the entire absolute URL when it begins with two slashes:

// relative path to application document root
$router->addRoute('<presenter>/<action>', ...);

// absolute path, relative to server hostname
$router->addRoute('/<presenter>/<action>', ...);

// absolute URL including hostname (but scheme-relative)
$router->addRoute('//<lang>.example.com/<presenter>/<action>', ...);

// absolute URL including schema
$router->addRoute('https://<lang>.example.com/<presenter>/<action>', ...);

Validation Expressions

A validation condition can be specified for each parameter using regular expression. For example, let's set id to be only numerical, using \d+ regexp:

$router->addRoute('<presenter>/<action>[/<id \d+>]', 'Homepage:default');

The default regular expression for all parameters is [^/]+, ie everything except the slash. If a parameter is supposed to match a slash as well, we set the regular expression to .+.

// accepts https://example.com/a/b/c, path is 'a/b/c'
$router->addRoute('<path .+>', '...');

Optional Sequences

Square brackets denote optional parts of mask. Any part of mask may be set as optional, including those containing parameters:

$router->addRoute('[<lang [a-z]{2}>/]<name>', 'Article:show');

// Accepted URLs:      Parameters:
//   /en/download        action => view, lang => en, name => download
//   /download           action => view, lang => null, name => download

Of course, when a parameter is part of an optional sequence, it also becomes optional. If it does not have a default value, it will be null.

Optional sections can also be in the domain:

$router->addRoute('//[<lang=en>.]example.com/<presenter>/<action>', ...);

Sequences may be freely nested and combined:

$router->addRoute(
	'[<lang [a-z]{2}>[-<sublang>]/]<name>[/page-<page=0>]',
	'Homepage:default'
);

// Accepted URLs:
//   /cs/hello
//   /en-us/hello
//   /hello
//   /hello/page-12

URL generator tries to keep the URL as short as possible, so what can be omitted is omitted. Therefore, for example, a route index[.html] generates a path /index. You can reverse this behavior by writing an exclamation mark after the left square bracket:

// accepts both /hello and /hello.html, generates /hello
$router->addRoute('<name>[.html]');

// accepts both /hello and /hello.html, generates /hello.html
$router->addRoute('<name>[!.html]');

Optional parameters (ie. parameters having default value) without square brackets do behave as if wrapped like this:

$router->addRoute('<presenter=Homepage>/<action=default>/<id=>');

// equals to:
$router->addRoute('[<presenter=Homepage>/[<action=default>/[<id>]]]');

To change how the rightmost slash is generated, i.e. instead of /homepage/ get a /homepage, adjust the route this way:

$router->addRoute('[<presenter=Homepage>[/<action=default>[/<id>]]]');

Wildcards

In the absolute path mask, we can use the following wildcards to avoid, for example, the need to write a domain to the mask, which may differ in the development and production environment:

  • %tld% = top level domain, e.g. com or org
  • %sld% = second level domain, e.g. example
  • %domain% = domain without subdomains, e.g. example.com
  • %host% = whole host, e.g. www.example.com
  • %basePath% = path to the root directory
$router->addRoute('//www.%domain%/%basePath%/<presenter>/<action>', ...);
$router->addRoute('//www.%sld%.%tld%/%basePath%/<presenter>/<action', ...);

Advanced notation

The second parameter of the route, which we often write in the format Presenter:action, is an abbreviation, which we can also write in the form of a field, where we directly state the (default) values ​​of individual parameters:

$router->addRoute('<presenter>/<action>[/<id \d+>]', [
	'presenter' => 'Homepage',
	'action' => 'default',
]);

Or we can use this form, notice the rewriting of the validation regular expression:

use Nette\Routing\Route;

$router->addRoute('<presenter>/<action>[/<id>]', [
	'presenter' => [
		Route::VALUE => 'Homepage',
	],
	'action' => [
		Route::VALUE => 'default',
	],
	'id' => [
		Route::PATTERN => '\d+',
	],
]);

These more talkative formats are useful for adding other metadata.

Filters and Translations

It's a good practice to write source code in English, but what if you need your website to have translated URL to different language? Simple routes such as:

$router->addRoute('<presenter>/<action>', 'Homepage:default');

will generate English URLs, such as /product/123 or /cart. If we want to have presenters and actions in the URL translated to Deutsch (e.g. /produkt/123 or /einkaufswagen), we can use a translation dictionary. To add it, we already need a “more talkative” variant of the second parameter:

use Nette\Routing\Route;

$router->addRoute('<presenter>/<action>', [
	'presenter' => [
		Route::VALUE => 'Homepage',
		Route::FILTER_TABLE => [
			// string in URL => presenter
			'produkt' => 'Product',
			'einkaufswagen' => 'Cart',
			'katalog' => 'Catalog',
		],
	],
	'action' => [
		Route::VALUE => 'default',
		Route::FILTER_TABLE => [
			'liste' => 'list',
		],
	],
]);

Multiple dictionary keys can by used for the same presenter. They will create various aliases for it. The last key is considered to be the canonical variant (i.e. the one that will be in the generated URL).

The translation table can be applied to any parameter in this way. However, if the translation does not exist, the original value is taken. We can change this behavior by adding Router::FILTER_STRICT => true and the route will then reject the URL if the value is not in the dictionary.

In addition to the translation dictionary in the form of an array, it is possible to set own translation functions:

use Nette\Routing\Route;

$router->addRoute('<presenter>/<action>/<id>', [
	'presenter' => [
		Route::VALUE => 'Homepage',
		Route::FILTER_IN => function (string $s): string { ... },
		Route::FILTER_OUT => function (string $s): string { ... },
	],
	'action' => 'default',
	'id' => null,
]);

The function Route::FILTER_IN converts between the parameter in the URL and the string, which is then passed to the presenter, the function FILTER_OUT ensures the conversion in the opposite direction.

The parameters presenter, action and module already have predefined filters that convert between the PascalCase resp. camelCase style and kebab-case used in the URL. The default value of the parameters is already written in the transformed form, so, for example, in the case of a presenter, we write <presenter=ProductEdit> instead of <presenter=product-edit>.

Global Filters

Besides filters for specific parameters, you can also define global filters that receive an associative array of all parameters that they can modify in any way and then return. Global filters are defined under null key.

use Nette\Routing\Route;

$router->addRoute('<presenter>/<action>', [
	'presenter' => 'Homepage',
	'action' => 'default',
	null => [
		Route::FILTER_IN => function (array $params): array { ... },
		Route::FILTER_OUT => function (array $params): array { ... },
	],
]);

Global filters give you the ability to adjust the behavior of the route in absolutely any way. We can use them, for example, to modify parameters based on other parameters. For example, translation <presenter> and <action> based on the current value of parameter <lang>.

If a parameter has a custom filter defined and a global filter exists at the same time, custom FILTER_IN is executed before the global and vice versa global FILTER_OUT is executed before the custom. Thus, inside the global filter are the values of the parameters presenter resp. action written in PascalCase resp. camelCase style.

ONE_WAY flag

One-way routes are used to preserve the functionality of old URLs that the application no longer generates but still accepts. We flag them with ONE_WAY:

// old URL /product-info?id=123
$router->addRoute('product-info', 'Product:detail', $router::ONE_WAY);
// new URL /product/123
$router->addRoute('product/<id>', 'Product:detail');

When accessing the old URL, the presenter automatically redirects to the new URL so that search engines do not index these pages twice (see SEO and canonization).

Modules

If we have more routes that belong to one module, we can use withModule() to group them:

$router = new RouteList;
$router->withModule('Forum') // the following routers are part of the Forum module
	->addRoute('rss', 'Feed:rss') // presenter is Forum:Feed
	->addRoute('<presenter>/<action>')

	->withModule('Admin') // the following routers are part of the Forum:Admin module
		->addRoute('sign:in', 'Sign:in');

An alternative is to use the module parameter:

// URL manage/dashboard/default maps to presenter Admin:Dashboard
$router->addRoute('manage/<presenter>/<action>', [
	'module' => 'Admin'
]);

Subdomains

Route collections can be grouped by subdomains:

$router = new RouteList;
$router->withDomain('example.com')
	->addRoute('rss', 'Feed:rss')
	->addRoute('<presenter>/<action>');

You can also use wildcards in your domain name:

$router = new RouteList;
$router->withDomain('example.%tld%')
	...

Path Prefix

Route collections can be grouped by path in URL:

$router = new RouteList;
$router->withPath('/eshop')
	->addRoute('rss', 'Feed:rss') // matches URL /eshop/rss
	->addRoute('<presenter>/<action>'); // matches URL /eshop/<presenter>/<action>

Combinations

The above usage can be combined:

$router = (new RouteList)
	->withDomain('admin.example.com')
		->withModule('Admin')
			->addRoute(...)
			->addRoute(...)
		->end()
		->withModule('Images')
			->addRoute(...)
		->end()
	->end()
	->withDomain('example.com')
		->withPath('export')
			->addRoute(...)
			...

Query Parameters

Masks can also contain query parameters (parameters after the question mark in the URL). They cannot define a validation expression, but they can change the name under which they are passed to the presenter:

// use query parameter 'cat' as a 'categoryId' in application
$router->addRoute('product ? id=<productId> & cat=<categoryId>', ...);

Foo Parameters

We're going deeper now. Foo parameters are basically unnamed parameters which allow to match a regular expression. The following route matches /index, /index.html, /index.htm and /index.php:

$router->addRoute('index<? \.html?|\.php|>', 'Homepage:default');

It's also possible to explicitly define a string which will be used for URL generation. The string must be placed directly after the question mark. The following route is similar to the previous one, but generates /index.html instead of /index because the string .html is set as a “generated value”.

$router->addRoute('index<?.html \.html?|\.php|>', 'Homepage:default');

SimpleRouter

A much simpler router than the Route Collection is SimpleRouter. It can be used when there's no need for a specific URL format, when mod_rewrite (or alternatives) is not available or when we simply do not want to bother with user-friendly URLs yet.

Generates addresses in roughly this form:

http://example.com/?presenter=Product&action=detail&id=123

The parameter of the SimpleRouter constructor is a default presenter & action, ie. action to be executed if we open e.g. http://example.com/ without additional parameters.

// defaults to presenter 'Homepage' and action 'default'
$router = new Nette\Application\Routers\SimpleRouter('Homepage:default');

We recommend defining SimpleRouter directly in configuration file:

services:
	router: Nette\Application\Routers\SimpleRouter('Homepage:default')

SEO and Canonization

The framework increases SEO (search engine optimization) by preventing duplication of content at different URLs. If multiple addresses link to a same destination, eg /index and /index.html, the framework determines the first one as primary (canonical) and redirects the others to it using HTTP code 301. Thanks to this, search engines will not index pages twice and do not break their page rank. .

This process is called canonization. The canonical URL is the one generated by the router, i.e. by the first matching route in the collection without the ONE_WAY flag. Therefore, in the collection, we list primary routes first.

Canonization is performed by the presenter, more in the chapter canonization.

HTTPS

In order to use the HTTPS protocol, it is necessary to activate it on hosting and to configure the server.

Redirection of the entire site to HTTPS must be performed at the server level, for example using the .htaccess file in the root directory of our application, with HTTP code 301. The settings may differ depending on the hosting and looks something like this:

<IfModule mod_rewrite.c>
	RewriteEngine On
	...
	RewriteCond %{HTTPS} off
	RewriteRule .* https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
	...
</IfModule>

The router generates a URL with the same protocol as the page was loaded, so there is no need to set anything else.

However, if we exceptionally need different routes to run under different protocols, we will put it in the route mask:

// Will generate an HTTP address
$router->addRoute('http://%host%/<presenter>/<action>','Homepage:default');

// Will generate an HTTPS address
$router->addRoute('https://%host%/<presenter>/<action>','Admin:default');

Routing Debugger

We will not hide from you that routing may seem a bit magical at first, and before you get into it, Routing Debugger will be a good helper. This is a panel displayed in the Tracy Bar, which provides a clear list of routes as well as parameters that the router obtained from the URL.

The green bar represents the route that matched the current URL, the blue bar indicates the routes that would also match the URL if green did not overtake them. We see the current presenter & action further.

Route Caching

If the router has no dependencies, such as a database, and its factory does not accept any arguments, we can serialize its built-in form directly into the DI container and thus slightly speed up the application.

routing:
	cache: true

Custom Router

You can create your own router and naturally add it into your route collection. The router is an implementation of the Router interface with two methods:

use Nette\Http\IRequest as HttpRequest;
use Nette\Http\UrlScript;

class MyRouter implements Nette\Routing\Router
{
	public function match(HttpRequest $httpRequest): ?array
	{
		// ...
	}

	public function constructUrl(array $params, UrlScript $refUrl): ?string
	{
		// ...
	}
}

Method match processes the current request in the parameter $httpRequest (which offers more than just URL) into the an array containing the name of the presenter and its parameters. If it cannot process the request, it returns null.

Method constructUrl, on the other hand, generates an absolute URL from the array of parameters. It can use the information from parameter $refUrl, which is the current URL.

To add custom routert to the route collection, use add():

$router = new Nette\Application\Routers\RouteList;
$router->add(new MyRouter);
$router->addRoute(...);
...

Separated Usage

By separated usage, we mean the use of the router's capabilities in an application that does not use Nette Application and presenters. Almost everything we have shown in this chapter applies to it, with the following differences:

So again we will create a method that will build a router, for example:

namespace App\Router;

use Nette\Routing\RouteList;

class RouterFactory
{
	public static function createRouter(): RouteList
	{
		$router = new RouteList;
		$router->addRoute('rss.xml', [
			'controller' => 'RssFeedController',
		]);
		$router->addRoute('article/<id \d+>', [
			'controller' => 'ArticleController',
		]);
		...
		return $router;
	}
}

If you use a DI container, which we recommend, add the method to the configuration file again and then get the router together with the HTTP request from the container:

$router = $container->getByType(Nette\Routing\Router::class);
$httpRequest = $container->getByType(Nette\Http\IRequest::class);

Or we will create objects directly:

$router = App\Router\RouterFactory::createRouter();
$httpRequest = (new Nette\Http\RequestFactory)->fromGlobals();

Now we have to let the router to work:

$params = $router->match($httpRequest);
if ($params === null) {
	// no matching route found, we will send a 404 error
	exit;
}

// we process the received parameters
$controller = $params['controller'];
...

And vice versa, we will use the router to create the link:

$params = ['controller' => 'ArticleController', 'id' => 123];
$url = $router->constructUrl($params, $httpRequest->getUrl());

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