Simple Svelte Router for Single Page Applications (SPA), inspired by Vue Router. Features include:

• Nested route/view mapping.
• Modular, component-based router configuration.
• Route params, query, wildcards (powered by path-to-regexp).
• Navigation guards for navigation control.
• Links with automatic active CSS classes.
• HTML5 history mode or hash mode (powered by history).

To see the details code documentation, please read the Code Documentation.

This project is not being actively maintained by the author of package. Any community contribution would be more than welcomed keep this project alive.

Quick Links

• Webpack Setup
• Webpack Boilerplate Project Template
• Rollup Setup

Table of Content

• Svelte Router
  • Installation via NPM or Yarn
  • Webpack Setup
  • Webpack Boilerplate Project Template
  • Rollup Setup
  • Essentials
    • Setup the Router
    • Route Configuration
    • Dynamic Route Configuration
    • Route Redirection
    • Passing Props to Route Components
      • Automatically Pass Route Params as Component Props
      • Pass Custom Object as Component Props
      • Use a Function to Resolve the Component Props
      • Auto Passed Route Prop
    • Nested Routes
    • Router Link Component
      • Router Link Events
    • Router View Component
  • Advanced
    • Programmatic Navigation
    • Navigation Guard
      • Create a Navigation Guard
      • Navigation Guard Next Action
        • Continue
        • Abort
        • Redirect
        • Error
    • Lazy Loaded Component
  • API
    • Create Router
      • Router Options
      • Access Router Instance
    • Router Methods
      • start
      • push
      • replace
      • back
      • forward
      • go
      • routeURL
      • navigationGuard
      • onBeforeNavigation
      • onNavigationChanged
      • onError
    • Location Object
    • Route Object
    • Route Record Object
  • Changes
  • About
  • Contributing
    • Pull Request Process
  • License

npm install -D @spaceavocado/svelte-router

yarn add @spaceavocado/svelte-router -D

Please see the Svelte Webpack Template. Important setup in the webpack.config.js:

resolve: {
  // This alias is important to prevent svelte mismatch
  // between your code, and the 3rd party components.
  alias: {
    svelte: path.resolve('node_modules', 'svelte')
  },
  extensions: ['.mjs', '.js', '.svelte'],
  mainFields: ['svelte', 'browser', 'module', 'main']
},

module: {
  rules: [
    {
      test: /\.svelte$/,
      // Do not exclude: /(node_modules)/ since the router 
      // components are located in the node_modules
      use: {
        loader: 'svelte-loader',
        options: {
          emitCss: true,
          hotReload: true
        }
      }
    }
  ]
}

For a quick start, you can use svelte-router-template - Webpack boilerplate template project for spaceavocado/svelte-router.

Live Preview.

rollup.config.js:

import babel from 'rollup-plugin-babel';
import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import svelte from 'rollup-plugin-svelte';

export default {
  input: './src/index.js',
  output: {
    file: './dist/bundle.js',
    format: 'iife'
  },
  plugins: [
    resolve(),
    commonjs({
      include: 'node_modules/**',
    }),
    svelte(),
    babel({
      exclude: 'node_modules/**',
    }),
  ]
}

Note: All code below uses ES2015+.

All we need to do is map our components to the routes and add root RouterView component, here's a basic example of app component uses as the main Svelte component.

index.js:

// The base component
import App from './app.svelte';

// Turn on the engine
new App({
  target: document.body,
});

app.svelve:

<script>
import createRouter from '@spaceavocado/svelte-router';
import RouterView from '@spaceavocado/svelte-router/component/view';

// View components
import ViewHome from './views/home.svelte';
import View404 from './views/404.svelte';

createRouter({
  routes: [
    { 
      path: '/',
      name: 'HOME',
      component: ViewHome,
    },
    {
      path: '*',
      component: View404,
    },
  ],
});
</script>

<RouterView />

This is an example of the minimalist plug & play setup of the Svelte Router. For more details:

• Create Router
• Route Configuration
• Route View Component

A route can be configure with these properties:

createRouter({
  routes: [
    { 
      path: '/',
      name: 'HOME',
      component: ViewHome,
      meta: {
        static: 5,
        dynamic: () => {return 5;},
      }
    },
    { 
      path: '/services',
      name: 'SERVICES',
      children: [
        { 
          path: '/',
          name: 'SERVICES_HOME',
          component: ViewServices,
        },
        { 
          path: '/design',
          name: 'SERVICES_DESIGN',
          component: ViewServicesDesign,
          props: {
            title: 'Services / Design',
          }
        }
      ]
    },
    { 
      path: '/users/:id(\\d+)',
      name: 'USER_PROFILE',
      component: ViewUserProfile,
      props: (route) => {
        return {
          userId: route.params.id,
        };
      },
    }
  ],
});

• The route path could contain dynamic parameters, e.g. path: '/users/:id'. Please see path-to-regexp for more information how to configure the name, optional, etc,. parameters.
• Special case is path: '*' which means any URL, this route should be the last route in your routes definition.
• All resolved dynamic parameters are accessible on the resolved route object.

To redirect a route, you can configure it like so:

// Redirect from /a to /b
{ 
  path: '/a',
  redirect: '/b',
}

// External site redirect
// Must start with 'http' or 'https'
{ 
  path: '/a',
  redirect: 'https://github.com/spaceavocado/svelte-router',
}

// Redirect to named route
{ 
  path: '/a',
  redirect: {
    name: 'ROUTE_NAME',
  },
}

// Dynamic redirecting
// "to" is Route Object
// Return value must be URL or a Route.
{ 
  path: '/a',
  redirect: (to) => {
    return {
      name: 'ROUTE_NAME',
    }
  },
}

Please see Route Object for more details.

By default, props are not automatically passed to the route component, this could be change to:

All route dynamic props are auto-passed to the component.

// app.svelte
{ 
  path: '/users/:id(\\d+)',
  name: 'USER_PROFILE',
  component: ViewUserProfile,
  props: true,
}

// ViewUserProfile.svelte
export let id;

// app.svelte
{ 
  path: '/',
  name: 'HOME',
  component: ViewHome,
  props: {
    title: 'Hello World',
  },
}

// ViewHome.svelte
export let title;

Please see Route Object for more details.

// app.svelte
{ 
  path: '/users/:id(\\d+)',
  name: 'USER_PROFILE',
  component: ViewUserProfile,
  props: (route) => {
    return {
      title: 'User Profile',
      id: route.params.id,
    }
  },
}

// ViewUserProfile.svelte
export let title;
export let id;

Route property of type Route Object is auto-passed to the route component.

component.svelte:

<script>
export let route;
</script>

• Please see Route Configuration for the base information about the routes configuration.
• Nested route has access to its own parameters and all parent's route parameters:

  { 
    path: '/users/:id(\\d+)',
    children: [
      {
        path: '/',
        name: 'USER_DETAIL',
        component: ViewUserDetail,
      },
      {
        path: '/message/:msgId(\\d+)',
        name: 'USER_MESSAGE',
        component: ViewUserMessageDetail,
      }
    ],
  },
  {
    path: '/services',
    component: ViewServices,
    children: [
      path: '/design',
      component: ViewServicesDesign,
    ]
  }
  
  // Resolved USER_MESSAGE route will have access to 
  // id, and msgId params.

• The component could be omitted if the route has nested routes (please see the example above), it this case ViewRouter component will be used to pass through the components, please see Router View for more details.
• If the route has nested routes, and it has defined component, than the component must internally use Router View component to pass though the routed view components on it's own nested routes.
• All routes should start with trailing slash.

<script>
import RouterLink from '@spaceavocado/svelte-router/component/link';

<!-- URL -->
<RouterLink to='/services/design'>Navigate by URL</RouterLink>

<!-- Location Object -->
<RouterLink to={{name: 'USER_DETAIL', params:{id: 5}}>Navigate by Location</RouterLink>

The route link is the base component for routing action. The route link renders a < a > DOM element with click action triggering route change. The active class is auto-resolved. Component parameters:

<script>
import RouterLink from '@spaceavocado/svelte-router/component/link';

// Navigation has been completed
function handleOnCompleted() {}

// Navigation has been aborted
function handleOnAborted() {}
</script>

<RouterLink to='/services/design' on:completed={handleOnCompleted} on:aborted={handleOnAborted}>Navigate by URL</RouterLink>

<script>
import RouterView from '@spaceavocado/svelte-router/component/view';
</script>

<RouterView />

• The route view acts as SLOT for resolved route component, i.e. it will be replaced run-time with the component defined on the given route.
• For nested routes, if the parent route (the one having nested routes) has defined it's own component, the component must use internally ViewRouter component to pass through the nested route components. If the component is not defined on the parent route, it auto pass through.

Besides the Router Link Component, the route could be changed like so:

import {router} from '@spaceavocado/svelte-router';

// URL
$router.push('/services/design');

// Location Object
$router.push({
  name: 'USER_DETAIL',
  params: {
    id: 5,
  },
  query: {
    code: 'system_code',
  },
  hash: 'sidebar',
});

Note: the router can be accessed after the createRouter function is executed, and it must be accessed as $router since it is Svelte read-able store object.

More information:

• Location Object
• Router Methods

The navigation guards are primarily used to guard navigations either by redirecting it or canceling it.

import {router} from '@spaceavocado/svelte-router';

// The guard callback is called when a navigation occurs,
// the next function must be called to continue the navigation.
$router.navigationGuard((from, to, next) => {
  next();
});

Note: the router can be accessed after the createRouter function is executed, and it must be accessed as $router since it is Svelte read-able store object.

"from, to" are Route Object.

next();

Move on to the next hook in the pipeline. If no hooks are left, the navigation is confirmed.

next(false);

Abort the current navigation.

// URL
next('/services/design');

// Location Object
next({
  name: 'USER_DETAIL',
  params: {
    id: 5,
  },
  query: {
    code: 'system_code',
  },
  hash: 'sidebar',
});

Abort the current navigation and redirect to new navigation.

More information:

• Location Object

next(new Error('internal error'));

Abort the current navigation, and trigger onError event on the router.

More information:

• onError

View components could be loaded asynchronously, i.e. lazy loading, e.g:

app.svelve

<script>
import createRouter from '@spaceavocado/svelte-router';
import RouterView from '@spaceavocado/svelte-router/component/view';

// View components
import ViewHome from './views/home.svelte';
import View404 from './views/404.svelte';

// Webpack dynamic import
const asyncView = (view) => {
  return new Promise((resolve) => {
    const component = import(/* webpackChunkName: "view-[request]" */ `./view/${view}.svelte`);
    resolve(component);
  });
};

createRouter({
  routes: [
    { 
      path: '/',
      name: 'HOME',
      component: ViewHome,
    },
    {
      path: 'some-page',
      component: asyncView('some-page'),
    }
    {
      path: '*',
      component: View404,
    },
  ],
});
</script>

<RouterView />

Note: To load async component, the load function must return a Promise, and resolve must return a module object:

{
  // The default (default module export function) must the Svelte Component function
  // Please see the webpack example above.
  default: function(){}
}.

To see the details code documentation, please read the Code Documentation

import createRouter from '@spaceavocado/svelte-router';

// Please see the opts below.
const routerOpts = {};

// Router is Svelte read-able store, therefore it must be
// accessed with $ prefix, e.g. $router.
// To access the router instance in other files, please see "Access Router Instance".
const router = createRouter(routerOpts);

Throws when the route options are invalid.

Note: History modes could be accessed like so:

import {ROUTER_MODE} from '@spaceavocado/svelte-router';

Note: Hash types could be accessed like so:

import {HASH_TYPE} from '@spaceavocado/svelte-router';

More information:

• Route Configuration

import {router} from '@spaceavocado/svelte-router';

Note: It must be accessed as $router since it is the Svelte read-able store object, to resolved auto subscribe/unsubscribe.

All route methods are accessible on the router, please see Access Router Instance.

$router.start();

This method is auto-called by the root Router View Component; it handles the on page load route resolution.

Push to navigation.

$router.push(rawLocation, onComplete, onAbort);

Throws when the rawLocation is invalid or when the path is invalid.

Parameters:

Replace in navigation.

$router.replace(rawLocation, onComplete, onAbort);

Throws when the rawLocation is invalid or when the path is invalid.

Parameters:

Go one step back in the navigation history.

$router.back();

Go one step forward in the navigation history.

$router.forward();

Go to a specific history position in the navigation history.

$router.go(n);

Parameters:

Generate route URL from the the raw location.

const url = $router.routeURL(rawLocation);

Parameters:

Register a navigation guard which will be called whenever a navigation is triggered. All registered navigation guards are resolved in sequence. Navigation guard must call the next() function to continue the execution of navigation change. Please see Navigation Guard

const unregister = $router.navigationGuard(guard);

// To unregister the navigation guard:
unregister();
unregister = null;

Parameters:

"from, to" are Route Object.

Register a callback which will be called before execution of navigation guards.

const unregister = $router.onBeforeNavigation(callback);

// To unregister the event:
unregister();
unregister = null;

Parameters:

"from, to" are Route Object.

Register a callback which will be called when all navigation guards are resolved, and the final navigation change is resolved.

const unregister = $router.onNavigationChanged(callback);

// To unregister the event:
unregister();
unregister = null;

Parameters:

"from, to" are Route Object.

Register a callback which will be called when an error is caught during a route navigation.

const unregister = $router.onError(callback);

// To unregister the event:
unregister();
unregister = null;

Parameters:

// Location object example
{
  name: 'USER_DETAIL',
  params: {
    id: 5,
  },
  query: {
    code: 'system_code',
  },
  hash: 'sidebar',
}

// Considering that USER_DETAIL is /user/:id(\\d+)
// the resolved URL will be:
// /user/5?code=system_code#sidebar

To see the changes that were made in a given release, please lookup the tag on the releases page. The full changelog could be seen here changelog.md

This project was inspired by Vue Router, designed mainly to explore and test Svelte in SPA realm. Any feedback, contribution to this project is welcomed.

The project is in a beta phase, therefore there might be major changes in near future, the annotation should stay the same, though.

When contributing to this repository, please first discuss the change you wish to make via issue, email, or any other method with the owners of this repository before making a change.

1. Fork it
2. Create your feature branch (git checkout -b ft/new-feature-name)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin ft/new-feature-name)
5. Create new Pull Request

Please make an issue first if the change is likely to increase.

Svelte Router is released under the MIT license. See LICENSE.txt.