@dimjs/model-react
The react based state management of @dimjs
The usages
$ npm i @dimjs/model-react
Features
The State management library for React
Support Both Class and Hooks Api
Full TypeScript Support
100% test coverage, safe on production
Debug easily on test environment
import { Model } from '@dimjs/model-react';
// define model
const Todo = {
state: {
items: ['Install @dimjs/model-react', 'Read github docs', 'Build App'],
},
actions: {
add: (todo) => {
// s is the readonly version of state
// you can also return partial state here but don't need to keep immutable manually
// state is the mutable state
return (state) => {
state.items.push(todo);
};
},
},
};
// Model Register
const { useStore } = Model(Todo);
const App = () => {
return <TodoList />;
};
const TodoList = () => {
const [state, actions] = useStore();
return (
<div>
<Addon handler={actions.add} />
{state.items.map((item, index) => (
<Todo key={index} item={item} />
))}
</div>
);
};
Table of Contents
Core Concept
Model
Every model has its own state and actions.
const initialState = {
counter: 0,
light: false,
response: {},
};
interface StateType {
counter: number;
light: boolean;
response: {
code?: number;
message?: string;
};
}
interface ActionsParamType {
increment: number;
openLight: undefined;
get: undefined;
} // You only need to tag the type of params here !
const model: ModelType<StateType, ActionsParamType> = {
actions: {
increment: async (payload, { state }) => {
return {
counter: state.counter + (payload || 1),
};
},
openLight: async (_, { state, actions }) => {
await actions.increment(1); // You can use other actions within the model
await actions.get(); // support async functions (block actions)
actions.get();
await actions.increment(1); // + 1
await actions.increment(1); // + 2
await actions.increment(1); // + 3 as expected !
return { light: !state.light };
},
get: async () => {
await new Promise((resolve, reject) =>
setTimeout(() => {
resolve();
}, 3000),
);
return {
response: {
code: 200,
message: `${new Date().toLocaleString()} open light success`,
},
};
},
},
state: initialState,
};
export default Model(model);
// You can use these types when use Class Components.
// type ConsumerActionsType = getConsumerActionsType<typeof Model.actions>
// type ConsumerType = { actions: ConsumerActionsType; state: StateType }
// type ActionType = ConsumerActionsType
// export { ConsumerType, StateType, ActionType }
Model Register
@dimjs/model-react keeps the application state and actions in separate private stores. So you need to register them if you want to use them as the public models.
model/index.ts
import { Model } from '@dimjs/model-react';
import Home from '../model/home';
import Shared from '../model/shared';
const models = { Home, Shared };
export const { getInitialState, useStore, getState, actions, subscribe, unsubscribe } = Model(models);
useStore
The functional component in React ^16.8.0 can use Hooks to connect the global store. The actions returned from useStore can invoke dom changes.
The execution of actions returned by useStore will invoke the rerender of current component first.
It's the only difference between the actions returned by useStore and actions now.
import React from 'react';
import { useStore } from '../index';
// CSR
export default () => {
const [state, actions] = useStore('Home');
const [sharedState, sharedActions] = useStore('Shared');
return (
<div>
Home model value: {JSON.stringify(state)}
Shared model value: {JSON.stringify(sharedState)}
<button onClick={(e) => actions.increment(33)}>home increment</button>
<button onClick={(e) => sharedActions.increment(20)}>shared increment</button>
<button onClick={(e) => actions.get()}>fake request</button>
<button onClick={(e) => actions.openLight()}>fake nested call</button>
</div>
);
};
import { useStore, getState } from '../model/index';
const BasicHook = () => {
const [state, actions] = useStore('Counter');
useEffect(() => {
console.log('some mounted actions from BasicHooks');
return () =>
console.log(`Basic Hooks unmounted, current Counter state: ${JSON.stringify(getState('Counter'))}`);
}, []);
return (
<>
<div>state: {JSON.stringify(state)}</div>
</>
);
};
actions
You can call other models' actions with actions api
actions can be used in both class components and functional components.
actions always return promise with latest Partial data
import { actions } from './index';
const model = {
state: {},
actions: {
crossModelCall: () => {
actions.Shared.changeTheme('dark');
actions.Counter.increment(9);
},
},
};
export default model;
subscribe
subscribe(storeName, actions, callback) run the callback when the specific actions executed.
import { subscribe, unsubscribe } from './index';
const callback = () => {
const user = getState('User');
localStorage.setItem('user_id', user.id);
};
// subscribe action
subscribe('User', 'login', callback);
// subscribe actions
subscribe('User', ['login', 'logout'], callback);
// unsubscribe the observer of some actions
unsubscribe('User', 'login'); // only logout will run callback now
Advance Concept
immutable Actions
The actions use immer produce API to modify the Store. You can return a producer in action.
Using function as return value can make your code cleaner when you modify the deep nested value.
TypeScript Example
// StateType and ActionsParamType definition
// ...
const model: ModelType<StateType, ActionsParamType> = {
actions: {
increment: async (params, { state: s }) => {
// return (state: typeof s) => { // TypeScript < 3.9
return (state) => {
state.counter += params || 1;
};
},
decrease: (params) => (s) => {
s.counter += params || 1;
},
},
};
export default Model(model);
JavaScript Example
const Model = {
actions: {
increment: async (params) => {
return (state) => {
state.counter += params || 1;
};
},
},
};
SSR with Next.js
Store: shared.ts
const initialState = {
counter: 0,
};
const model: ModelType<StateType, ActionsParamType> = {
actions: {
increment: (params, { state }) => {
return {
counter: state.counter + (params || 1),
};
},
},
// Provide for SSR
asyncState: async (context) => {
await waitFor(4000);
return { counter: 500 };
},
state: initialState,
};
export default Model(model);
Global Config: _app.tsx
import { models, getInitialState, Models } from '../model/index'
let persistModel: any
interface ModelsProps {
initialModels: Models
persistModel: Models
}
const MyApp = (props: ModelsProps) => {
if ((process as any).browser) {
// First come in: initialModels
// After that: persistModel
persistModel = props.persistModel || Model(models, props.initialModels)
}
const { Component, pageProps, router } = props
return (
<Container>
<Component {...pageProps} />
</Container>
)
}
MyApp.getInitialProps = async (context: NextAppContext) => {
if (!(process as any).browser) {
const initialModels = context.Component.getInitialProps
? await context.Component.getInitialProps(context.ctx)
await getInitialState(undefined, { isServer: true }) // get all model initialState
// : await getInitialState({ modelName: 'Home' }, { isServer: true }) // get Home initialState only
// : await getInitialState({ modelName: ['Home', 'Todo'] }, { isServer: true }) // get multi initialState
// : await getInitialState({ data }, { isServer: true }) // You can also pass some public data as asyncData params.
return { initialModels }
} else {
return { persistModel }
}
}
Page: hooks/index.tsx
import { useStore, getState } from '../index'
export default () => {
const [state, actions] = useStore('Home')
const [sharedState, sharedActions] = useStore('Shared')
return (
<div>
Home model value: {JSON.stringify(state)}
Shared model value: {JSON.stringify(sharedState)}
<button
onClick={e => {
actions.increment(33)
}}
>
</div>
)
}
Single Page Config: benchmark.tsx
// ...
Benchmark.getInitialProps = async () => {
return await getInitialState({ modelName: 'Todo' }, { isServer: true });
};
Middleware
We always want to try catch all the actions, add common request params, connect Redux devtools and so on. We Provide the middleware pattern for developer to register their own Middleware to satisfy the specific requirement.
// Under the hood
const tryCatch: Middleware<{}> = async (context, restMiddlewares) => {
const { next } = context
await next(restMiddlewares).catch((e: any) => console.log(e))
}
// ...
let actionMiddlewares = [
tryCatch,
getNewState,
setNewState,
stateUpdater,
communicator,
devToolsListener
]
// ...
// How we execute an action
const consumerAction = (action: Action) => async (params: any) => {
const context: Context = {
modelName,
setState,
actionName: action.name,
next: () => {},
newState: null,
params,
consumerActions,
action
}
await applyMiddlewares(actionMiddlewares, context)
}
// ...
export { ... , actionMiddlewares}
You can override the actionMiddlewares and insert your middleware to specific position
Expand Context
const ExtCounter: ModelType<
{ name: string }, // State Type
{ ext: undefined }, // ActionParamsType
{ name: string } // ExtContextType
> = {
actions: {
// { state, action } => { state, action, [name] }
ext: (_, { name }) => {
return { name };
},
},
state: { name: '' },
};
const { useStore } = Model(ExtCounter, { name: 'test' });
// state.name = ''
const [state, actions] = useStore();
// ...
actions.ext();
// state.name => 'test'
Other Concept required by Class Component
Provider
The global state standalone can not effect the react class components, we need to provide the state to react root component.
import { PureComponent } from 'react';
import { Provider } from '@dimjs/model-react';
class App extends PureComponent {
render() {
return (
<Provider>
<Counter />
</Provider>
);
}
}
connect
We can use the Provider state with connect.
Javascript decorator version
import React, { PureComponent } from 'react';
import { Provider, connect } from '@dimjs/model-react';
const mapProps = ({ light, counter }) => ({
lightStatus: light ? 'open' : 'close',
counter,
}); // You can map the props in connect.
@connect('Home', mapProps)
export default class JSCounter extends PureComponent {
render() {
const { state, actions } = this.props;
return (
<>
<div>states - {JSON.stringify(state)}</div>
<button onClick={(e) => actions.increment(5)}>increment</button>
<button onClick={(e) => actions.openLight()}>Light Switch</button>
</>
);
}
}
TypeScript Version
import React, { PureComponent } from 'react';
import { Provider, connect } from '@dimjs/model-react';
import { StateType, ActionType } from '../model/home';
const mapProps = ({ light, counter, response }: StateType) => ({
lightStatus: light ? 'open' : 'close',
counter,
response,
});
type RType = ReturnType<typeof mapProps>;
class TSCounter extends PureComponent<{ state: RType } & { actions: ActionType }> {
render() {
const { state, actions } = this.props;
return (
<>
<div>TS Counter</div>
<div>states - {JSON.stringify(state)}</div>
<button onClick={(e) => actions.increment(3)}>increment</button>
<button onClick={(e) => actions.openLight()}>Light Switch</button>
<button onClick={(e) => actions.get()}>Get Response</button>
<div>message: {JSON.stringify(state.response)}</div>
</>
);
}
}
export default connect('Home', mapProps)(TSCounter);
FAQ
How can I disable the console debugger
import { middlewares } from '@dimjs/model-react';
// Find the index of middleware
// Disable all actions' log
middlewares.config.logger.enable = false;
// Disable logs from specific type of actions
middlewares.config.logger.enable = ({ actionName }) => ['increment'].indexOf(actionName) !== -1;
How can I add custom middleware
import { actionMiddlewares, middlewares, Model } from '@dimjs/model-react';
import { sendLog } from 'utils/log';
import Home from '../model/home';
import Shared from '../model/shared';
// custom middleware
const ErrorHandler: Middleware = async (context, restMiddlewares) => {
const { next } = context;
await next(restMiddlewares).catch((e: Error) => sendLog(e));
};
// Find the index of middleware
const getNewStateMiddlewareIndex = actionMiddlewares.indexOf(middlewares.getNewState);
// Replace it
actionMiddlewares.splice(getNewStateMiddlewareIndex, 0, ErrorHandler);
const stores = { Home, Shared };
export default Model(stores);
How can I make persist models
import { actionMiddlewares, Model } from '@dimjs/model-react'
import Example from 'models/example'
// Example, not recommend to use on production directly without consideration
// Write current State to localStorage after action finish
const persistMiddleware: Middleware = async (context, restMiddlewares) => {
localStorage.setItem('__REACT_MODEL__', JSON.stringify(context.Global.State))
await context.next(restMiddlewares)
}
// Use on all models
actionMiddlewares.push(persistMiddleware)
Model({ Example }, JSON.parse(localStorage.getItem('__REACT_MODEL__')))
// Use on single model
const model = {
state: JSON.parse(localStorage.getItem('__REACT_MODEL__'))['you model name']
actions: { ... },
middlewares: [...actionMiddlewares, persistMiddleware]
}
How can I deal with local state
What should I do to make every Counter hold there own model?
class App extends Component {
render() {
return (
<div className="App">
<Counter />
<Counter />
<Counter />
</div>
);
}
}
Counter model
interface State {
count: number;
}
interface ActionParams {
increment: number;
}
const model: ModelType<State, ActionParams> = {
state: {
count: 0,
},
actions: {
increment: (payload) => {
// immer.module.js:972 Uncaught (in promise) Error: An immer producer returned a new value *and* modified its draft. Either return a new value *or* modify the draft
// Not allowed
// return state => (state.count += payload)
return (state) => {
state.count += payload;
};
},
},
};
Counter.tsx
const Counter = () => {
const [{ useStore }] = useState(() => Model(model));
const [state, actions] = useStore();
return (
<div>
<div>{state.count}</div>
<button onClick={() => actions.increment(3)}>Increment</button>
</div>
);
};
export default Counter;
actions throw error from immer.module.js
immer.module.js:972 Uncaught (in promise) Error: An immer producer returned a new value *and* modified its draft. Either return a new value *or* modify the draft
How to fix:
actions: {
increment: (payload) => {
// Not allowed
// return state => (state.count += payload)
return (state) => {
state.count += payload;
};
};
}
How can I customize each model's middlewares?
You can customize each model's middlewares.
import { actionMiddlewares, Model } from '@dimjs/model-react';
const delayMiddleware: Middleware = async (context, restMiddlewares) => {
await timeout(1000, {});
context.next(restMiddlewares);
};
const nextCounterModel: ModelType<CounterState, NextCounterActionParams> = {
actions: {
add: (num) => {
return (state) => {
state.count += num;
};
},
increment: async (num, { actions }) => {
actions.add(num);
await timeout(300, {});
},
},
// You can define the custom middlewares here
middlewares: [delayMiddleware, ...actionMiddlewares],
state: {
count: 0,
},
};
export default Model(nextCounterModel);
Notes
"noImplicitThis": true,
- In order to generated
index.d.ts
usingimport {} from @dimjs/model
we must be setup some configurations as below.
// faltjs.dts.js
{
compilationOptions: {
followSymlinks: false,
},
entries: [
libraries: {
importedLibraries: ['@dimjs/model'],
},
]
}
// tsconfig.json
{
"extends": "../../tsconfig.json",
"compilerOptions": {
// setup "paths" is {}
"paths": {}
}
}