Lit Redux Router

Declarative way of routing for lit powered by pwa-helpers and redux.

A minimal router solution (~1.7 kb Gzipped) that consist in using lit-route elements and connecting them to the store.

The routing approach is based on the PWA Starter Kit.

Install

Install this library and its peer dependencies

npm i lit-redux-router lit pwa-helpers redux

Usage

Firstly ensure that the redux store has been created with the lazyReducerEnhancer, which allows for reducers to be installed lazily after initial store setup.

import { createStore, compose, combineReducers } from 'redux';
import { reducer } from './reducer';
import { lazyReducerEnhancer } from 'pwa-helpers';

export const store = createStore(reducer, compose(lazyReducerEnhancer(combineReducers)));

Then the router needs to connect to a redux store.

import { LitElement, html } from 'lit';
import { connectRouter } from 'lit-redux-router';
import store from './store.js';

connectRouter(store);

lit-route component can render the components when the path attribute matches. The corresponding active lit-route element will reflect the active attribute.

class MyApp extends LitElement {
  render() {
    return html`
      <div class="app-content">
        <lit-route path="/" active><h1>Home</h1></lit-route>
        <lit-route path="/about"><h1>About</h1></lit-route>
      </div>
    `;
  }
}
customElements.define('my-app', MyApp);

Ideally all content would be in a component and can be passed to lit-route through a component attribute.

class AppHome extends LitElement {
  render() {
    return html`<h1>Home</h1>`;
  }
}
customElements.define('app-home', AppHome);

class AppAbout extends LitElement {
  render() {
    return html`<h1>About</h1>`;
  }
}
customElements.define('app-about', AppAbout);

class MyApp extends LitElement {
  render() {
    return html`
      <div class="app-content">
        <lit-route path="/" component="app-home"></lit-route>
        <lit-route path="/about" component="app-about"></lit-route>
      </div>
    `;
  }
}
customElements.define('my-app', MyApp);

lit-route can map path variables and inject them in the provided component.

class AppProduct extends LitElement {
  static get properties() {
    return {
      id: String,
    };
  }

  render() {
    return html`<h1>Product with id: ${this.id}</h1>`;
  }
}
customElements.define('app-product', AppProduct);

class MyApp extends LitElement {
  render() {
    return html`
      <div class="app-content">
        <lit-route path="/products/:id" component="app-product"></lit-route>
      </div>
    `;
  }
}
customElements.define('my-app', MyApp);

When no path attribute is provided to lit-route, it will render when no route matches (404)

class MyApp extends LitElement {
  render() {
    return html`
      <div class="app-content">
        <lit-route path="/"><h1>Home</h1></lit-route>
        <lit-route><h1>404 Not found</h1></lit-route>
      </div>
    `;
  }
}
customElements.define('my-app', MyApp);

To trigger navigation without using a link element, the action navigate can be imported and triggered with the wanted path

import { navigate } from 'lit-redux-router';
import store from './store.js';

class MyApp extends LitElement {
  goTo(path) {
    store.dispatch(navigate(path));
  }

  render() {
    return html`
      <div class="app-content">
        <button @click="${() => this.goTo('/about')}">learn more about us</button>
      </div>
    `;
  }
}
customElements.define('my-app', MyApp);

To lazy load a component on route change and optionally show a loading component while waiting for the import to resolve

import { navigate } from 'lit-redux-router';
import store from './store.js';

class MyApp extends LitElement {
  render() {
    return html`
      <div class="app-content">
        <lit-route
          path="/docs"
          component="my-docs"
          .resolve="${() => import('./docs.js')}"
          loading="my-loading"
        ></lit-route>
      </div>
    `;
  }
}
customElements.define('my-app', MyApp);

class MyLoading extends LitElement {
  render() {
    return html`
      <style>
        h1 {
          margin-top: 0;
          margin-bottom: 16px;
        }
      </style>
      <h1>Loading...</h1>
    `;
  }
}

customElements.define('my-loading', MyLoading);

The window will scroll to top by default, to disable add the attribute scrollDisable

<lit-route path="/whatever" component="my-whatever" scrollDisable></lit-route>

To scroll to the route element on load, you can set the scrollIntoViewOptions object in the attribute .scrollOpt

<lit-route
  path="/whatever"
  component="my-whatever"
  .scrollOpt="${{behavior: 'smooth', block:'end', inline:'nearest'}}"
></lit-route>

Check a more comprehensive example in https://github.com/fernandopasik/lit-redux-router/blob/main/demo/

Development

Start server with example and watch mode for building the library

npm run start

Run lint and test tasks

npm run test
npm run lint

Build the library

npm run build

Check the full size of the library

npm run size

Built with

• regexparam - A tiny utility that converts route patterns into RegExp
• lit - Lit is a simple library for building fast, lightweight web components
• pwa-helpers - Small helper methods or mixins to help you build web apps
• Redux - Predictable state container for JavaScript apps

Contributors ✨

Thanks goes to these wonderful people (emoji key):

This project follows the all-contributors specification. Contributions of any kind welcome!

License

MIT (c) 2018 Fernando Pasik