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Upgrading

This page documents the breaking changes between major versions and how to migrate your application.

Fork history

This package is a fork of ItalyPaleAle/svelte-spa-router. The @bmlt-enabled releases start at 5.x (Svelte 5) and add path-based routing and base-path support. For the full, fork-specific release history see the CHANGELOG.

Upgrading to 5.x​

The 5.x line requires Svelte 5 or later. When upgrading from 4.x to 5.x, note the following breaking changes.

Use router.loc, router.location, and router.querystring instead of the store exports​

The legacy store exports (loc, location, querystring, and params) are removed in favor of properties on the router object.

Update your imports and usages as follows:

<script>
-import {loc, location, querystring, params} from '@bmlt-enabled/svelte-spa-router'
+import {router} from '@bmlt-enabled/svelte-spa-router'

// usage examples
-params.subscribe(p => console.log(p))
+$effect(() => console.log(router.params))

-$: hasQueryString = !!$querystring
+const hasQueryString = $derived(!!router.querystring)
</script>

-Currently at {$location}
+Currently at {router.location}

Use callback props instead of component events​

Pass callback props to the router component rather than listening to custom component events. For example, on:routeLoading becomes onRouteLoading:

 <script>
-    function handleRouteLoading(event) {
-        console.log(event.detail)
+    function handleRouteLoading(detail) {
+        console.log(detail)
     }
 </script>

-<Router {routes} on:routeLoading={handleRouteLoading} />
+<Router {routes} onRouteLoading={handleRouteLoading} />

Likewise, migrate the other route callbacks too:

-<Router
-    {routes}
-    on:routeLoaded={handleRouteLoaded}
-    on:conditionsFailed={handleConditionsFailed}
-/>
+<Router
+    {routes}
+    onRouteLoaded={handleRouteLoaded}
+    onConditionsFailed={handleConditionsFailed}
+/>

Upgrading to 4.x​

When upgrading from 3.x to 4.x, note the following breaking change. (4.x is designed to work with Svelte 3 and 4; for Svelte 5, use 5.x.)

wrap must be imported from svelte-spa-router/wrap​

The deprecated wrap method exported from the package root has been removed and replaced with an import from the /wrap sub-path. See New wrap method below for details.

Upgrading to 3.x​

URL parameters are now automatically decoded​

Params extracted from the URL are now automatically decoded. For example, with a route /book/:name and a user navigating to /book/dante%27s%20inferno:

  • ❌ Old behavior (2.x and older): params.name was dante%27s%20inferno
  • ✅ New behavior (3.x+): params.name is dante's inferno

This is done by invoking decodeURIComponent. If your application was decoding URL parameters itself, remove that when upgrading.

New wrap method​

The old wrap method exported from the package root was deprecated in favor of the wrap method exported from /wrap. The new method's signature accepts a single options object and adds support for many features including dynamically-imported routes.

To upgrade while maintaining the same functionality:

// ❌ Old
import {wrap} from '@bmlt-enabled/svelte-spa-router'

const routes = {
    // wrap(component, userData, ...conditions)
    '/foo': wrap(
        Foo,
        {foo: 'bar'},
        (detail) => { /* ... */ },
    ),
}
// ✅ New
import {wrap} from '@bmlt-enabled/svelte-spa-router/wrap'

const routes = {
    // wrap(options)
    '/foo': wrap({
        component: Foo,
        userData: {foo: 'bar'},
        conditions: [
            (detail) => { /* ... */ },
        ],
    }),
}

See Route wrapping for all the properties wrap supports.

Upgrading to 2.x​

use:active syntax changes​

The use:active action now takes a single argument: a dictionary with path and className (and inactiveClassName). As a shorthand, you can pass just a string, interpreted as path.

<!-- ❌ Version 1.x -->
<a href="/hello/user" use:link use:active={'/hello/*', 'active'}>Say hi!</a>

<!-- ✅ Version 2.x+ -->
<a href="/hello/user" use:link use:active={{path: '/hello/*', className: 'active'}}>Say hi!</a>

See Active links for the current options.