Statecharts as components. No classes. Pure declarative state transitions.
MIT License
Use XState Machines as components.
npm install ember-statechart-component
In app/app.js / app/app.ts, a one time setup function will need to be called so that the ComponentManager is registered.
import Application from '@ember/application';
import config from 'ember-app/config/environment';
import loadInitializers from 'ember-load-initializers';
import Resolver from 'ember-resolver';
import { setupComponentMachines } from 'ember-statechart-component';
export default class App extends Application {
modulePrefix = config.modulePrefix;
podModulePrefix = config.podModulePrefix;
Resolver = Resolver;
}
loadInitializers(App, config.modulePrefix);
setupComponentMachines();
See: https://stately.ai/docs/migration
Example with Ember Octane
// app/components/toggle.js
import { createMachine } from 'xstate';
export default createMachine({
initial: 'inactive',
states: {
inactive: { on: { TOGGLE: 'active' } },
active: { on: { TOGGLE: 'inactive' } },
},
});
Usage:
<Toggle as |state send|>
{{state.value}}
<button {{on 'click' (fn send 'TOGGLE')}}>
Toggle
</button>
</Toggle>
The default template for every createMachine(..)
is
{{yield this.state this.send}}
but that can be overriden to suit your needs by defining your own template.
The this
is an instance of the XState Interpreter
// app/components/authenticated-toggle.js
import { getService } from 'ember-statechart-component';
import { createMachine } from 'xstate';
export default createMachine({
initial: 'inactive',
states: {
inactive: {
on: {
TOGGLE: [
{
target: 'active',
cond: 'isAuthenticated',
},
{ actions: ['notify'] },
],
},
},
active: { on: { TOGGLE: 'inactive' } },
},
}, {
actions: {
notify: (ctx) => {
getService(ctx, 'toasts').notify('You must be logged in');
},
},
guards: {
isAuthenticated: (ctx) => getService(ctx, 'session').isAuthenticated,
},
});
Usage:
<AuthenticatedToggle as |state send|>
{{state.value}}
<button {{on 'click' (fn send 'TOGGLE')}}>
Toggle
</button>
</AuthenticatedToggle>
<Toggle as |state send|>
{{#if (state.matches 'inactive')}}
The inactive state
{{else if (state.matches 'active')}}
The active state
{{else}}
Unknown state
{{/if}}
<button {{on 'click' (fn send 'TOGGLE')}}>
Toggle
</button>
</Toggle>
Having type checking with these state machines can be done automatically
after importing the /glint
file in your types/<app-name>/glint-registry.d.ts
.
import "@glint/environment-ember-loose";
import "@glint/environment-ember-loose/native-integration";
import "ember-page-title/glint";
// This import extends the type of `StateMachine` to be glint-compatible
import 'ember-statechart-component/glint';
declare module "@glint/environment-ember-loose/registry" {
export default interface Registry {
// How to define globals from external addons
}
}
@config
This argument allows you to pass a MachineOptions for actions, services, guards, etc.
Usage:
// app/components/toggle.js
import { createMachine, assign } from 'xstate';
export default createMachine({
initial: 'inactive',
states: {
inactive: { on: { TOGGLE: 'active' } },
active: {
on: {
TOGGLE: {
target: 'inactive',
actions: ['toggleIsOn']
}
}
},
},
});
<Toggle
@config={{hash
actions=(hash
toggleIsOn=@onRoomIlluminated
)
}}
as |state send|>
<button {{on 'click' (fn send 'TOGGLE')}}>
Toggle
</button>
</Toggle>
@context
Sets the initial context. The current value of the context can then be accessed via state.context
.
Usage:
// app/components/toggle.js
import { createMachine, assign } from 'xstate';
export default createMachine({
initial: 'inactive',
states: {
inactive: {
on: {
TOGGLE: {
target: 'active',
actions: ['increaseCounter']
}
}
},
active: {
on: {
TOGGLE: {
target: 'inactive',
actions: ['increaseCounter']
}
}
},
},
}, {
actions: {
increaseCounter: assign({
counter: (context) => context.counter + 1
})
}
});
<Toggle @context=(hash counter=0) as |state send|>
<button {{on 'click' (fn send 'TOGGLE')}}>
Toggle
</button>
<p>
Toggled: {{state.context.counter}} times.
</p>
</Toggle>
@state
The machine will use @state
as the initial state.
Any changes to this argument
are not automatically propagated to the machine.
An ARGS_UPDATE
event (see details below) is sent instead.
An event will be sent to the machine for you, ARGS_UPDATE
, along
with all named arguments used to invoke the component.
See the Contributing guide for details.
This project is licensed under the MIT License.