@fabienjuif/myrtille
v0.6.0
Published
An immutable (but feeling mutable) one-way state manager without reducers
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@fabienjuif/myrtille
An immutable (but feeling mutable) one-way state manager without reducers
Features
- 🔄 One-way state manager: your store is the single source of truth
- 💎 Immutable but feels mutable
- ⛏️ Hackable
- 💡 Based on events (actions)
- 📖 Compatible with redux-devtools
Inspirations
- https://github.com/rakunteam/k-ramel
- https://github.com/jamiebuilds/bey
The goal
The goal is to have a simple state manager, without being strictely related to single view library (like React or Vue). The Redux pattern, having a one-way state management, is a good pattern but Redux suffers from boilerplate, and once you add middleware you don't have clear separation of concerns. Myrtille tries to fix these drawbacks by using immer under the hood and by merging "reducers" and "reactions" into one place: listeners.
We also want to make sure your UI component tree is optimized and only refreshes when needed, that's why you can give a path
to subscribers, you can make sure your component tree will be refreshed only when this path updates.
One of the last goals that Myrtille aims at is to let the developper doing whatever he wants with this library, that's why the store is always given and usable inside your callbacks, hack-it!
Installation
npm install --save @fabienjuif/myrtille
yarn add @fabienjuif/myrtille
pnpm install --save @fabienjuif/myrtille
API
createStore(initialState: Object) -> Store
- create a store with the given initial state
- eg:
const store = createStore({ todos: [] })
Store.setState(newState: Object) -> void
- set state to the given one and triggers listeners
Store.getState() -> State
- get the current state
Store.mutate((state: State) -> void): void
Store.dispatch(action: String | Object) -> void
- dispatch an action that listeners can register on. If the action is a string, the
action
is created by myrtille to follow the standard rule:{ type: $yourString }
- eg:
store.dispatch('FETCH_TODOS')
- eg:
store.dispatch({ type: 'ADD_TODO', payload: { id: 2, label: 'new' }})
- dispatch an action that listeners can register on. If the action is a string, the
Store.addListener(action: String | Action | Function, callback: Function((store: Store, action: Action) -> void) | void) -> Function
- add a listener to the store, a listener listen to an action, when this
action
is dispatched, the registeredcallback
is called. - you can set your
callback
at first argument, in which it will be called for every actions dispatched. - you can play with the store in the given callback (dispatch new action, register mutations, etc.)
- calling the returned function will remove your callback
- eg: take a look at listeners examples
- add a listener to the store, a listener listen to an action, when this
Store.subscribe(path: String | Function, callback: Function(store: Store, oldState: State, action: Action) | void) -> Function
- subcribe to state mutations at given
path
. The registeredcallback
is called whenever the store was mutated at givenpath
. - you can set your
callback
at first argument, in which it will be called for every dispatch (even if there is no mutation) - if you set path to
''
(empty string), the callback will be called only for root mutations - you can play with the store in the given callback (dispatch new action, register mutations, etc.) but prefer using listeners and dispatching actions.
- calling the returned function will unsubscribe your callback
- subcribe to state mutations at given
Store.contexts: Object
- used to retrieve some informations from your callbacks given to
addListener
andsubscribe
- eg:
store.contexts.firebase = require('firebase/app')
- used to retrieve some informations from your callbacks given to
Listeners examples
Async and mutation
- Listen to an action that looks like
{ type: 'FETCH_TODOS' }
- Fetch todos
- Set todos in store
const store = createStore({ todos: [] })
store.subscribe((store) => { console.log('new state!', store.getState()) })
// the listener to focus on
store.addListener('FETCH_TODOS', async (store) => {
const todos = await (await fetch('https://my-api/todos')).json()
store.mutate(state => {
state.todos = todos
})
})
// dispatch the listened action
store.dispatch('FETCH_TODOS')
retrieve action informations
- Listen to
ADD_TODO
action (that can be dispatched by a click from the UI) - Add a new todo with information given in the action's payload
const store = createStore({ todos: [] })
store.subscribe((store) => { console.log('new state!', store.getState()) })
// the listener to focus on
store.addListener('ADD_TODO', (store, action) => {
store.mutate(state => {
state.todos.push(action.payload)
})
})
// dispatch the listened action
store.dispatch({ type: 'ADD_TODO', payload: { id: 2, label: 'new' } })
dispatch in a listener
- Listen to
@@ui/CLEAR_TODOS
(that can be dispatched by a click from the UI) - React by calling
CLEAR_TODOS
if todos are not already empty
const store = createStore({ todos: [{ id: 1, label: 'finish the documentation' }] })
store.addListener((store, oldState, action) => { console.log('new action is dispatched!', action) })
store.addListener('CLEAR_TODOS', store => { store.mutate(state => { state.todos = [] }) })
// the listener to focus on
store.addListener({ type: '@@ui/CLEAR_TODOS' }, store => {
if (store.getState().todos && store.getState().todos.length > 0) {
store.dispatch('CLEAR_TODOS')
}
})
// dispatch the listened action
store.dispatch('@@ui/CLEAR_TODOS')
Bindings
React
import {} from "@fabienjuif/myrtille/react"
API
createStore(initialState: Object) -> Store
- Please look at API.
provider(store: Store) -> Function(React.Component) -> React.Component
Provider({ store: Store, children }) -> React.Element
useDispatch() -> Function
useListeners(listeners: [][(String | Action), Function]) -> void
useStateAt(path: String | void) -> Any
useStore -> Store
Context: React.Context