XState Router. Add routes to your XState machine.
npm install xstate-routerXState Router. Add routes to your XState machine and maintain it in sync with the actual route.
If you want to use this solution with hooks use-router-machine.
Install the library with npm i xstate-router.
If you don't have XState installed, install it: npm i xstate
Try the live example here: https://codesandbox.io/s/rllly3pyxp.
The routerMachine function returns an interpreter:
``javascript
import { routerMachine } from 'xstate-router'
const machineConfig = {
initial: 'main',
context: { myValue: 0 },
states: {
main: { meta: { path: '/' } },
blog: { meta: { path: '/blog' } },
},
}
const service = routerMachine({
config: machineConfig,
options,
initialContext,
})
// The state changes on a route change and the route changes on a state change.
service.onTransition(state => console.log(state.value))
// The context is enhanced with router properties.
service.onChange(ctx => console.log(ctx))
/* Context
{
myValue: 0,
// Router properties:
match,
location,
history,
}
*/
`$3
1. match:
Tells you whether the route in the location matches the current state's path. If it matches it contains an object holding properties for each route parameter's value if the path was parameterized. Examples: null (not matching), {} (no parameters), { param1: 4711 }history.location
1. location:
The current value of routerMachine(...)
1. history: accepts a history object as fourth parameter. If it is missing it defaults to createBrowserHistory() (from package 'history') and is published in the context.
if you translate to a state having a parameterized route then you have to ensure that context.match contains the values of those parameters. Otherwise the placeholder is shown in the route. Example:
`javascript`
states: {
list: { meta: { path: '/items' },
on: {
ShowDetails: {
target: 'details',
actions: assign((ctx, event) => ({
...ctx,
match: { id: event.item }
}))
}
}
}
details: { meta: { path: '/items/:id:/details'} }
}`
where the event trigger could look like this:html`
Paths could have parameters such as /items/:id:/details and regular expressions, for more information please read this: https://github.com/pillarjs/path-to-regexp.
If a route changes then a parameterized event 'route-changed' is fired: e.g. { dueToStateTransition: "true", route: "/blog", service: / the xstate interpreter / }. dueToStateTransition
1. If the route changes because a state is entered which has a route configured, then is true. If the route changes because the location was changed (either by the user in the browsers location bar or by a script changing history.location), then dueToStateTransition is false.route
1. gives you the current route which causes the eventservice
1. provides the xstate interpreter which can be used to send another event.
Placing an on: 'router-changed' event at a state can be used to avoid leaving the current state if the route changes. Think of a state which might show unsaved data and you want to ask the user 'Leave and loose unsaved data?'. If you decide to accept the new route anyway you have to resend the event:`javascript``
on: {
'route-changed': {
cond: (context, event) => event.dueToStateTransition === false
&& !event.processed, // interfere only new events
actions: (context, event) => {
if (context.unsavedData) return; // suppress current route change
event.processed = true; // mark event as processed
event.service.send(event); // resend the event to establish the origin route change
}
}
},