A simple SPA routing and state management library for everyday use
Demo
For an interactive demo, visit ReplIt
npm install suuntaSuunta doesn't pack any dependencies, and therefore doesn't bring it's own rendering library either.
The easiest way to get started is to install lit and create a renderer with that as shown below.
import { FooView } from "./foo";
import { html, render } from "lit";
import { Suunta } from "suunta";
const routes = [
{
path: "/",
view: html`<p>Hello world!</p>`
},
{
path: "/foo",
view: FooView,
title: "Example - Foo View"
}
] as const;
// This part can be written however you want. Suunta provides you with the
// necessary data, you handle the rendering.
const renderer = (view, route, renderTarget) => {
render(html`${view}`, renderTarget);
};
const routerOptions = {
routes,
renderer,
target: document.body
};
const router = new Suunta(routerOptions);
router.start();Suunta supports dynamic routes with the {keyword}-notation.
If you want the matching to only match certain types of data, you can supply a regex for the matcher.
You can access properties of your dynamic routes with router.getCurrentView()?.route.params?.id
const routes: Route[] = [
{
path: "/user/{id}(\\d+)",
name: "User profile",
view: () => html`<p>User page for id ${router?.getCurrentView()?.params.id}</p>`
},
{
path: "/search/{matchAll}",
name: "Search",
view: html`<p>Search page for ${router?.getCurrentView()?.params.matchAll}</p>`
},
{
path: "/user/{id}(\\d+)/search/{matchAll}",
name: "User profile with search",
view: () => html`
<p>User page for id ${router?.getCurrentView()?.params.id}</p>
<p>Search page for ${router?.getCurrentView()?.params.matchAll || "Nothing"}</p>
`
},
{
path: "/{notFoundPath}(.*)",
name: "404",
view: html`<p>Page not found</p>`
},
];A lot of views have state. And that state can change, and so should the page content with it.
For state management, Suunta provides a createState hook, which will take the initial state of your view as a parameter.
When any of the values of that state object is directly manipulated, the view will update accordingly.
import { html } from 'lit';
import { createState } from 'suunta/state';
export const View = () => {
const state = createState({
count: 0,
});
const addCount = () => {
state.count += 1;
};
return () => html`
<p>Foo View</p>
<p>Count: ${state.count}</p>
<button @click=${addCount}>Count++</button>
`;
};For some use cases you might want to have state that is shared between multiple views, and is also reactive.
For these cases, the use of the createGlobalState hook is recommended.
This hook should not be used to replace the createState hook, but to implement those features, where a shared reactive state is useful for the
productivity and efficiency of the application.
When values of globalState objects are updated, all of the views managed by the current Suunta instance will be updated.
For most applications only using a single view at a time, this won't affect performance, but for views with subviews through the Child Routes, this will cause an performance hit.
// ../index.js
import { createGlobalState } from "suunta";
export const globalState = createGlobalState({
count: 0
})
// FooView.js
import { html } from 'lit';
import { createState } from 'suunta/state';
import { globalState } from "../index.js";
export const View = () => {
const addCount = () => {
globalState.count += 1;
};
return () => html`
<p>Foo View</p>
<p>Count: ${globalState.count}</p>
<button @click=${addCount}>Count++</button>
`;
};Most of modern web applications tend to handle some kind of API calls to an external service.
When managing async connections to external services, you need to manage multiple states. There's loading, errors, data etc.
Suunta comes packed with an utility class inside the suunta/fetch sub-package, which provides request
state management that works with the Suunta state system.
import { html } from "lit";
import { fetchPending, pendingApiResponse } from "suunta/fetch";
export function View() {
const request = pendingApiResponse(
fetchPending<GetAllCustomerInfoResponse>("http://localhost:8080/customers"),
);
return () => html`
<h2>Users</h2>
${request.loading
? html`<p>Loading...</p>`
: html`
<ul>
${request.result.customers.map(
(c) => html` <li>${c.firstName} ${c.lastName}</li> `,
)}
</ul>
`}
`;
}The pendingApiResponse function works out of the box with Hey API generated SDK's.
import { getAllCustomerInfo } from "../hey-api/sdk.gen";
const request = pendingApiResponse(getAllCustomerInfo);There is also a out-of-the-box implementation with Suunta named fetchPending, which only wraps the fetch API
and provides some simple utilities to it.
Some people however might want some more granular control over their process and want to write their own fetch wrappers. That is also supported and encouraged by Suunta! A good starting point would be something along the lines of:
import { RequestResult } from "suunta/fetch/core";
export function fetchPending<T>(input: RequestInfo | URL, init?: RequestInit): () => Promise<RequestResult<T>> {
return async function () {
const request = new Request(input, init);
const response = await fetch(request);
if (!response.ok) {
const error = await response.text();
return {
response,
request,
error,
data: undefined,
};
}
const data = await response.json() as T;
return {
response,
request,
error: undefined,
data,
};
};
}With Suunta, you don't have to go through the hassle of going through your whole codebase with CTRL - F after changing a route.
You can define your routes using the resolve function and generate routes dynamically by the name of said route.
const routes = [
{
name: "Home",
path: "/",
view: HomeView
},
{
name: "UserView",
path: "/users/{userId}",
view: UserView
children: [
{
name: "UserAttendances",
path: "/attendances/{attendanceId}",
view: UserAttendanceView
}
]
},
]
const homeView = router.resolve("Home");
// > homeView => /
const userView = router.resolve("UserView", 123);
// > userView => /users/123
const attendanceView = router.resolve("UserAttendances", 123, "suunta-course");
// > attendanceView => /users/123/attendances/suunta-course
html`<a href="${router.resolve("UserView", 123)}">To user view</a>`If you define your routes as a constant, you will also get Typescript type hints for your routes.
const routes = [
{
name: "Home",
path: "/",
view: HomeView
},
{
name: "UserView",
path: "/users/{userId}",
view: UserView
children: [
{
name: "UserAttendances",
path: "/attendances/{attendanceId}",
view: UserAttendanceView
}
]
},
] as const;
// _________________
// |Home |
// |UserView |
// |UserAttendances |
// |________________|
router.resolve("")Supplying redirects is as easy as adding a redirect property onto your route, and targetting another view by name with it.
const routes: Route[] = [
{
path: "/",
name: "Home",
view: html`<p id="needle">Hello world!</p>`
},
{
path: "/redirect",
name: "Redirect",
redirect: "Home"
}
]Providing a 404 page for you application is done by creating a all-matching wildcard route, and placing it at the bottom of your route list.
const routes: Route[] = [
{
path: "/",
name: "Home",
view: html`<p id="needle">Hello world!</p>`
},
{
path: "/{notFoundPath}(.*)",
name: "404",
view: html`<p>Page not found</p>`
},
]You can also make your 404 pages a redirect
const routes: Route[] = [
{
path: "/",
name: "Home",
view: html`<p id="needle">Hello world!</p>`
},
{
path: "/{notFoundPath}(.*)",
name: "404",
redirect: "Home"
},
]For cases where you have a bunch of views and want to squeeze out some extra performance from your packages, you can package split your code by dynamically importing your routes.
Suunta will handle the rest.
// ./views/foo.js
import { html } from "lit";
export const FooView = () => html`<p id="needle">
Foo bar
</p>`;
// router.js
import { BarView } from "./views/bar.js";
const FooView = () => import("./views/foo.js");
const routes: Route[] = [
{
path: "/",
name: "Home",
view: html`<p id="needle">Hello world!</p>`
},
{
path: "/foo",
name: "Foo",
view: FooView
},
{
path: "/bar",
name: "Bar",
view: BarView
},
];
const routerOptions: SuuntaInitOptions = {
routes,
target: "#outlet"
};
router = new Suunta(routerOptions);By using a <suunta-view> pseudoelement, you can tell Suunta to render the wanted content to a said location on page.
By default Suunta will render into the document.body
<body>
<suunta-view></suunta-view>
</body>The <suunta-view> outlet can be especially useful for rendering sub-views. If you want your view to have a navigatable sub-view, meaning that you want the view to render, without it un-rendering the previous view,
you can do that utilizing the suunta-view element and child routes
const routes: Route[] = [
{
path: '/',
name: 'Home',
view: HelloView
},
{
path: '/sub',
view: SubView,
children: [
{
path: '/sub',
view: SubView,
children: [
{
path: '/sub',
view: SubView,
children: [
{
path: '/sub',
view: SubViewFloor,
},
],
},
],
},
],
},
}
export function SubView() {
return () => html`
<p>
This is a view. By adding a child view to this view, and appending a
<code><suunta-view></code> container into it, we can render subviews
</p>
<a href="${window.location.href}/sub">Deeper</a>
<suunta-view></suunta-view>
`;
}By navigating to /sub/sub/sub/sub, we get a DOM looking like this:
<body>
<p>This is a view...</p>
<a href="/sub/sub">Deeper</a>
<suunta-view>
<p>This is a view...</p>
<a href="/sub/sub/sub">Deeper</a>
<suunta-view>
<p>This is a view...</p>
<a href="/sub/sub/sub/sub">Deeper</a>
<suunta-view>
<p>This is a subview floor</p>
</suunta-view>
</suunta-view>
</suunta-view>
</body>And when navigating backwards, only the subviews are un-rendered. The whole page does not require a refresh.
Suunta provides lifecycle hooks to plug into the navigation phases from within your own views.
import { html } from "lit-html";
import { onNavigated, onUpdated } from "suunta/triggers";
import { createState } from "suunta/state";
export function HomeView() {
const state = createState({
count: 0
});
console.log("HomeView loaded");
// Triggers whenever a navigation has occured
onNavigated(() => {
console.log("HomeView navigated to");
});
// Triggers whenever the current view's state object's value is updated
// e.g. when state.count is incremented
onUpdated(updatedProperties => {
console.log('Update', updatedProperties);
});
return () => html`
<button @click=${() => state.count += 1}>Clicked ${state.count} times</button>
`;
}