Router configuration
Learn about configuring the Router.
The router allows you to configure how it interprets and handles routing in your Aurelia applications. The customize method on the RouterConfiguration object can be used to configure router settings.
Complete Configuration Reference
The router accepts the following configuration options through RouterConfiguration.customize() (all map directly to RouterOptions except for basePath):
useUrlFragmentHash
boolean
false
When true, uses hash (#/path) URLs instead of pushState. Leave false for clean URLs.
useHref
boolean
true
Enables the router to intercept standard href links. Set to false if you only want to route via the load attribute.
historyStrategy
'push' | 'replace' | 'none' | (instructions) => HistoryStrategy
'push'
Controls how each navigation interacts with history. Provide a function to choose per navigation.
basePath
string | null
null
Overrides the base segment used to resolve relative routes. Defaults to document.baseURI.
activeClass
string | null
null
CSS class applied by the load attribute when a link is active.
useNavigationModel
boolean
true
Generates the navigation model so you can build menus from IRouteContext.routeConfigContext.navigationModel.
buildTitle
(transition: Transition) => string | null
null
Customises how page titles are produced. Return null to skip title updates.
restorePreviousRouteTreeOnError
boolean
true
Restores the previous route tree if a navigation throws, preventing partial states.
treatQueryAsParameters
boolean
false (deprecated)
Treats query parameters as route parameters. Avoid new usage; scheduled for removal in the next major release.
Pass a partial options object—the router merges your values with the defaults so you only specify what changes. Configure options before the router starts (for example, via
AppTask) so navigations consistently use the same settings.
Choose between hash and pushState routing using useUrlFragmentHash
useUrlFragmentHashIf you do not provide any configuration value, the default is pushState routing. If you prefer hash-based routing to be used, you can enable this like so:
import Aurelia from 'aurelia';
import { RouterConfiguration } from '@aurelia/router';
import { MyApp } from './my-app';
Aurelia
.register(RouterConfiguration.customize({ useUrlFragmentHash: true }))
.app(MyApp)
.start();By calling the customize method, you can supply a configuration object containing the property useUrlFragmentHash and supplying a boolean value. If you supply true this will enable hash mode. The default is false.
If you are working with pushState routing, you will need a <base> element with href attribute (for more information, refer MDN) in the head of your document. The scaffolded application from the CLI includes this in the index.html file, but if you're starting from scratch or building within an existing application you need to be aware of this.
Configuring basePath
basePathConfiguring a base path is useful in many real-life scenarios. One such example is when you are hosting multiple smaller application under a single hosting service. In this case, you probably want the URLs to look like https://example.com/app1/view42 or https://example.com/app2/view21. In such cases, it is useful to specify a different base#href value for every app.
Run the following example to understand how the value defined in base#href is affecting the URLs.
When you open the example in a new browser tab, you can note that the URL in the address bar looks the HOSTING_PREFIX/app/home or HOSTING_PREFIX/app/about. This is also true for the href values in the a tags. This happens because <base href="/app"> is used in the index.ejs (producing the index.html). In this case, the router is picking up the baseURI information and performing the routing accordingly.
This needs bit more work when you are supporting multi-tenancy for your app. In this case, you might want the URLs look like https://example.com/tenant-foo/app1/view42 or https://example.com/tenant-bar/app2/view21. You cannot set the document.baseURI every time you start the app for a different tenant, as that value is static and readonly, read from the base#href value.
With router you can support this by setting the basePath value differently for each tenant, while customizing the router configuration, at bootstrapping phase. Following is an example that implements the aforementioned URL convention. To better understand, open the the example in a new tab and check the URL in address bar when you switch tenants as well as the links in the a tags.
The actual configuration takes place in the main.ts while customizing the router configuration in the following lines of code.
There are also the following links, included in the my-app.html, to simulate tenant switch/selection.
Note the a tags with external attribute. Note that when you switch to a tenant, the links in the a tags also now includes the tenant name; for example when we switch to tenant 'foo' the 'Home' link is changed to /foo/app/home from /app/home.
Provide a custom location manager
If your host does not behave like a normal browser history stack (for example, a native WebView, an Electron shell, or a sandbox that proxies URLs), override the router’s location manager. The router always resolves ILocationManager from DI and ships with a browser-based implementation. Register your own class that implements the same public surface (startListening, stopListening, handleEvent, pushState, replaceState, getPath, addBaseHref, removeBaseHref) before the router starts:
Because RouterConfiguration registers BrowserLocationManager as a singleton, registering your custom implementation afterward replaces it everywhere. Match the method contracts from the linked file so the router keeps receiving normalized URLs and can keep raising au:router:location-change.
Swap the URL parser
RouterOptions stores an _urlParser instance that is derived from useUrlFragmentHash. Advanced apps can replace that parser before any navigation happens. The _urlParser field is marked readonly, so use Writable<T> from @aurelia/kernel when mutating:
Every call to ViewportInstruction.toUrl, router.load, or router.generatePath now runs through your parser while still using the same API surface as the built-in implementation.
Customizing title
A buildTitle function can be used to customize the default behavior of building the title. For this example, we assume that we have the configured the routes as follows:
With this route configuration in place, when we navigate to /home, the default-built title will be Home | Aurelia. We can use the following buildTitle function that will cause the title to be Aurelia - Home when users navigate to / or /home route.
Check out the following live example. You might need to open the demo in a new tab to observe the title changes.
Translating the title
When localizing your app, you would also like to translate the title. Note that the router does not facilitate the translation by itself. However, there are enough hooks that can be leveraged to translate the title. To this end, we would use the data property in the route configuration to store the i18n key.
As data is an object of type Record<string, unknown>, you are free to chose the property names inside the data object. Here we are using the i18n property to store the i18n key for individual routes.
In the next step we make use of the buildTitle customization as well as a AppTask hook to subscribe to the locale change event.
This customization in conjunction with the previously shown routing configuration will cause the title to be Aurelia - Startseite when user is navigated to / or /home route and the current locale is de. Here we are assuming that the i18n resource for the de locale contains the following.
The following example demonstrate the title translation.
Enable or disable the usage of the href custom attribute using useHref
href custom attribute using useHrefBy default, the router will allow you to use both href as well as load for specifying routes. Where this can get you into trouble is external links, mailto: links and other types of links that do not route. A simple example looks like this:
This seemingly innocent and common scenario by default will trigger the router and will cause an error.
You have two options when it comes to working with external links. You can specify the link as external using the external attribute.
Or, you can set useHref to false (default is true) and only ever use the load attribute for routes.
Configure browser history strategy
Using the historyStrategy configuration option it can be instructed, how the router should interact with the browser history object. This configuration option can take the following values: push, replace, and none.
push
pushThis is the default strategy. In this mode, the router will interact with Browser history to push a new navigation state each time a new navigation is performed. This enables the end users to use the back and forward buttons of the browser to navigate back and forth in an application using the router.
Check out the following example to see this in action.
The main configuration can be found in the main.ts.
To demonstrate the push behavior, there is a small piece of code in the my-app.ts that listens to router events to create informative text (the history property in the class) from the browser history object that is used in the view to display the information.
As you click the Home and About links in the example, you can see that the new states are being pushed to the history, and thereby increasing the length of the history.
replace
replaceThis can be used to replace the current state in the history. Check out the following example to see this in action. Note that the following example is identical with the previous example, with the difference of using the replace-value as the history strategy.
As you interact with this example, you can see that new states are replacing old states, and therefore, unlike the previous example, you don't observe any change in the length of the history.
none
noneUse this if you don't want the router to interact with the history at all. Check out the following example to see this in action. Note that the following example is identical with the previous example, with the difference of using the none-value as the history strategy.
As you interact with this example, you can see that there is absolutely no change in the history information, indicating non-interaction with the history object.
Override configured history strategy
You can use the navigation options to override the configured history strategy for individual routing instructions.
Return a dynamic history strategy
RouterOptions.historyStrategy is declared as ValueOrFunc<HistoryStrategy>, so you can supply a function whenever you call RouterConfiguration.customize. That callback receives the ViewportInstructionTree for the pending transition, allowing you to branch on route metadata:
The router invokes your function right before it pushes or replaces browser history inside router.load, so every navigation—declarative or programmatic—follows the same rule.
Configure active class
Using the activeClass option you can add a class name to the router configuration. This class name is used by the load custom attribute when the associated instruction is active. The default value for this option is null, which also means that the load custom attribute won't add any class proactively. Note that the router does not define any CSS class out-of-the-box. If you want to use this feature, make sure that you defines the class as well in your stylesheet.
Disable navigation model generation
If you're not using the navigation model feature for building menus, you can disable it to improve performance:
This prevents the router from generating navigation model data, which can be useful in applications with many routes where you don't need the navigation model functionality.
Error recovery configuration
The restorePreviousRouteTreeOnError option controls what happens when navigation fails:
With the default true setting, if navigation fails (due to guards returning false, component loading errors, etc.), the router will restore the previous working route. Setting this to false provides stricter error handling but requires your application to handle error states properly.
Observing navigation state while configuring the router
Beyond setting up routes, hash/push mode, or titles, you can optionally observe the active route and track query parameters. One way is to inject ICurrentRoute in any of your components. Another is to watch router events:
This can help debug or log your router's runtime state. See the ICurrentRoute docs for an example usage.
Treat query parameters as path parameters
When the treatQueryAsParameters property in the router configuration is set to true, the router will treat query parameters as path parameters. The default value is false.
treatQueryAsParameters is deprecated and will be removed in the next major version.
Advanced Configuration Scenarios
Combining Multiple Options
Most real-world applications will need to combine multiple configuration options:
Environment-Specific Configuration
You might want different configurations for different environments:
Micro-frontend Configuration
When building micro-frontends, you might need specific base path configurations:
Single-Page Application Embedded in Existing Site
When your Aurelia app is embedded within a larger traditional website:
Common Configuration Patterns
Mobile-Optimized Configuration
Debug-Friendly Development Configuration
Router lifecycle (advanced)
The router exposes start(performInitialNavigation: boolean) and stop(), but when you register RouterConfiguration the router is started and stopped automatically via AppTask.
Use
router.stop()if you temporarily need to suspend routing (for example, while showing a modal flow that should ignore browser back/forward).If you call
router.stop(), callrouter.start(false)to resume listening without triggering another initial navigation.Delaying the very first navigation requires a custom router configuration, because
RouterConfigurationalways starts the router during app activation.
Troubleshooting Configuration Issues
Common Problems and Solutions
Problem: Routes not working with useUrlFragmentHash: false
Problem: External links being processed by router
Problem: Navigation not updating browser history
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