"State machine" for basic purposes.
There're many redux-state-machine implementations. krasimir/stent is pretty good among others (just opinion). But:
Stentdoes not allow to "lock" the execution thread. Therefore impossible to verify thatnextstep strictly follows (corresponds) by theprev.- Has no standard mechanics for state rollback.
If these points are not significant for you, Stent might be your best choice.
- History-like api
- Lock mechanics
- Multi-step transition declarations
- Typescript
typings/index.d.ts - Flowtype libdef
flow-typed/index.flow.jsshould be found by Flow. If not, add[lib]section to.flowconfig
import {Machine} from '@qiwi/cyclone'
const handler1 = () => {}
const handler2 = () => {}
const opts = {
initialState: 'foo',
initialData: {a: 'AAA'},
transitions: {
'foo>bar': true, // NOTE applies static DEFAULT_HANDLER
'bar>baz': handler1,
'baz>foo': handler2,
'foo>bar>baz>foo': handler1
},
historySize: 5, // default = 10
}
const machine = new Machine(opts)Returns machine state digest:
machine.current() // {state: 'foo', data: {a: 'AAA'}, id: '0.2234...', date: 2018-10-07T16:59:23.644Z}Transits the machine to a new state:
machine.next('bar', {optional: 'args'}, 'for', 'handler')
machine.current() // {state: 'bar', data: {...}, ...}Reverts the last transition:
machine.current() // {state: 'bar', data: {...}, ...}
machine.prev() // btw, it returns machine ref
machine.current() // {state: 'foo', data: {...}, ...}Prevents state update.
machine.lock('key')
machine.next('qux', {a: 'a'}) // MachineError: Lock violation
machine.unlock('invalidKey') // MachineError: Invalid unlock key
machine.unlock('key')DEFAULT_HANDLER('foo', 'bar') // 'bar'
DEFAULT_HANDLER('foo', 'bar', 'baz') // 'baz'Imagine, Rematch model:
import txn from '../../../../api/txn'
import Machine from '@qiwi/cyclone'
const machine = new Machine({
initialState: 'init',
initialData: {},
transitions: {
'init>loading': true,
'loading>ok': (state, res) => res,
'loading>err': (state, res) => res,
'ok>loading': true,
'err>loading': true
}
})
export default {
state: machine.current(),
reducers: {
next(prev, next, ...payload) {
return machine.next(next, ...payload).current()
}
},
effects: {
async read (opts) {
this.next('loading')
const res = await txn.readList(opts)
this.next('ok', res)
}
}
}