Svelte Routing
A declarative Svelte routing library with SSR support.
Getting started
Look at the example folder for an example project setup.
Install
npm install --save svelte-routingUsage
<!-- App.svelte -->
<script>
import { Router, Link, Route } from "svelte-routing";
import Home from "./routes/Home.svelte";
import About from "./routes/About.svelte";
import Blog from "./routes/Blog.svelte";
export let url = "";
</script>
<Router url="{url}">
<nav>
<Link to="/">Home</Link>
<Link to="about">About</Link>
<Link to="blog">Blog</Link>
</nav>
<div>
<Route path="blog/:id" component="{BlogPost}" />
<Route path="blog" component="{Blog}" />
<Route path="about" component="{About}" />
<Route path="/"><Home /></Route>
</div>
</Router>// main.js
import App from "./App.svelte";
const app = new App({
target: document.getElementById("app"),
hydrate: true
});// server.js
const { createServer } = require("http");
const app = require("./dist/App.js");
createServer((req, res) => {
const { html } = app.render({ url: req.url });
res.write(`
<!DOCTYPE html>
<div id="app">${html}</div>
<script src="/dist/bundle.js"></script>
`);
res.end();
}).listen(3000);API
Router
The Router component supplies the Link and Route descendant components with routing information through context, so you need at least one Router at the top of your application. It assigns a score to all its Route descendants and picks the best match to render.
Router components can also be nested to allow for seamless merging of many smaller apps.
Properties
| Property | Required | Default Value | Description |
|---|---|---|---|
basepath |
'/' |
The basepath property will be added to all the to properties of Link descendants and to all path properties of Route descendants. This property can be ignored in most cases, but if you host your application on e.g. https://example.com/my-site, the basepath should be set to /my-site. |
|
url |
'' |
The url property is used in SSR to force the current URL of the application and will be used by all Link and Route descendants. A falsy value will be ignored by the Router, so it's enough to declare export let url = ''; for your topmost component and only give it a value in SSR. |
Link
A component used to navigate around the application.
Properties
| Property | Required | Default Value | Description |
|---|---|---|---|
to |
✔ ️ | '#' |
URL the component should link to. |
replace |
false |
When true, clicking the Link will replace the current entry in the history stack instead of adding a new one. |
|
state |
{} |
An object that will be pushed to the history stack when the Link is clicked. |
|
getProps |
() => ({}) |
A function that returns an object that will be spread on the underlying anchor element's attributes. The first argument given to the function is an object with the properties location, href, isPartiallyCurrent, isCurrent. Look at the NavLink component in the example project setup to see how you can build your own link components with this. |
Route
A component that will render its component property or children when its ancestor Router component decides it is the best match.
All properties other than path and component given to the Route will be passed to the rendered component.
Potential path parameters will be passed to the rendered component as properties. A wildcard * can be given a name with *wildcardName to pass the wildcard string as the wildcardName property instead of as the * property.
Potential path parameters are passed back to the parent using props, so they can be exposed to the slot template using let:params.
<Route path="blog/:id" let:params>
<BlogPost id="{params.id}" />
</Route>Properties
| Property | Required | Default Value | Description |
|---|---|---|---|
path |
'' |
The path for when this component should be rendered. If no path is given the Route will act as the default that matches if no other Route in the Router matches. |
|
component |
null |
The component constructor that will be used for rendering when the Route matches. If component is not set, the children of Route will be rendered instead. |
navigate
A function that allows you to imperatively navigate around the application for those use cases where a Link component is not suitable, e.g. after submitting a form.
The first argument is a string denoting where to navigate to, and the second argument is an object with a replace and state property equivalent to those in the Link component.
<script>
import { navigate } from "svelte-routing";
function onSubmit() {
login().then(() => {
navigate("/success", { replace: true });
});
}
</script>link
An action used on anchor tags to navigate around the application. You can add an attribute replace to replace the current entry in the history stack instead of adding a new one.
<script>
import { link } from "svelte-routing";
</script>
<Router>
<a href="/" use:link>Home</a>
<a href="/replace" use:link replace>Replace this URL</a>
<!-- ... -->
</Router>links
An action used on a root element to make all relative anchor elements navigate around the application. You can add an attribute replace on any anchor to replace the current entry in the history stack instead of adding a new one. You can add an attribute noroute for this action to skip over the anchor and allow it to use the native browser action.
<!-- App.svelte -->
<script>
import { links } from "svelte-routing";
</script>
<div use:links>
<Router>
<a href="/">Home</a>
<a href="/replace" replace>Replace this URL</a>
<a href="/native" noroute>Use the native action</a>
<!-- ... -->
</Router>
</div>SSR Caveat
In the browser we wait until all child Route components have registered with their ancestor Router component before we let the Router pick the best match. This approach is not possible on the server, because when all Route components have registered and it is time to pick a match the SSR has already completed, and a document with no matching route will be returned.
We therefore resort to picking the first matching Route that is registered on the server, so it is of utmost importance that you sort your Route components from the most specific to the least specific if you are using SSR.