React-cargo

react-cargo is a minimal state management tool for React with managed updates on state transition. react-cargo is easy to setup, just install and you are ready to add global state to your application without the need of writing any boilerplate code. react-cargo exposes easy to use hook based api's.

Installation

To install the stable version of react-cargo

npm install react-cargo

or

yarn add react-cargo

List of hooks

• useStore
• useStoreValue
• useStoreSetter
• useSelector
• useResetStore

Methods

• createStore

Creating a store

Creating a store is as easy as calling a function with some argument. Using createStore, you can create a StateInstance, which takes an object with a key and a default state

key : should be unique accross the application

state : can take in Primitive as well as Non-primitive data types

import {createStore} from "react-cargo";

export const counter = createStore({
    key : 'counter',
    state : 0
})

Using a store in your component

We can use useStore, useStoreValue,useStoreSetter or useSelector to use a state in our component.

import {createStore} from "react-cargo";

const counter = createStore({
    key : 'counter',
    state : 0
});

function Counter(){
    let [count,setCount] = useStore(counter);
    return <div>
        <h4>Counter {count}</h4>
        <Actions/>
    </div>
}

function Actions(){
    let [count,setCount] = useStore(counter);

    const increment = ()=>setCount(count+1);

    const decrement = ()=>count(count-1);

    return <div>
        <button onClick={increment}>Increment</button>
        <button onClick={decrement}>Decrement</button>
    </div>
}

Hooks

useStore :

Returns a tuple where the first element is the value of state and the second element is a setter function that will update the value of the given state when called.

 function useStore<T>(stateInstance: StoreInstance<T>):[T, Dispatch<T>]

• stateInstance : an instance returned by createStore
  
  

This API is similar to the React useState() hook except it takes a stateInstance (returned by createStore). It returns a tuple of the current value of the state and a setter function. The setter function takes a new value.

Example

import { useStore, createStore} from 'react-cargo';

let counterState = createStore({
    key :'counter',
    state : 0
});

function Counter(){
    let [count,setCounter] = useStore(counterState);
    
    //setter syntax 1
    let increment = ()=> setCounter(prevState=>prevState + 1);
    //setter syntax 2
    let decrement = ()=> setCounter(count - 1);

    return (
        <>
            <h5>{count}</h5>
            <button onClick={increment}> + </button>
            <button onClick={decrement}> - </button>
        </>
    )
}

useStoreValue

Returns the value of the given stateInstance.

 function useStoreValue<T>(stateInstance: StoreInstance<T>): T;

• stateInstance : an instance returned by createStore
  
  

This hook should be used where a component intends only to read state.

Example

  import { useStoreSetter, useStoreValue, createStore} from 'react-cargo';
 
  let nameStore = createStore({
    key :'storedemo',
    state : ''
  });
 
  function App(){
    return (
       <>
          <NameView/>
          <Actions/>
       </>
    )
  }
 
  function ViewCount(){
       let name = useStoreValue(nameStore);
 
       return <h5>{name}</h5>
  }
 
  function Actions(){
       let setName = useStoreSetter(nameStore);
 
       return <p>
              <input
                type="text"
                onChange={(e) => setName(e.target.value)}
                placeholder="Enter a name"
              />
          </p>
  }

useStoreSetter :

Returns a setter to set the state of a provided stateInstance

  function useStoreSetter<T>(stateInstance: StoreInstance<T>): Dispatch<T>;

• stateInstance : an instance returned by createStore
  
  

Example

import { useStoreSetter, useStoreValue, createStore} from 'react-cargo';

 let nameStore = createStore({
    key :'storedemo',
    state : ''
 });

 function App(){
   return (
      <>
         <NameView/>
         <Actions/>
      </>
   )
 }

 function ViewCount(){
      let name = useStoreValue(nameStore);

      return <h5>{name}</h5>
 }

 function Actions(){
      let setName = useStoreSetter(nameStore);

      return <p>
             <input
               type="text"
               onChange={(e) => setName(e.target.value)}
               placeholder="Enter a name"
             />
         </p>
 }

useResetStore :

Returns a resetter function to reset the state of a provided stateInstance to its initial state

  function useResetStore<T>(stateInstance: StoreInstance<T>): () => void;

• stateInstance : an instance returned by createStore
  
  

Example

  import { useStore, useStoreValue, createStore, useResetStore} from 'react-cargo';
 
  let counterState = createStore({
    key :'counter',
    state : 0
  });
 
  function Counter(){
    return (
       <>
          <ViewCount/>
          <Actions/>
          <Reset/>
       </>
    )
  }
 
  function Reset(){
       let reset = useResetStore(counterState);
 
       return <button onClick={reset}>Reset Counter</button>
  }
 
  function ViewCount(){
       let count = useStoreValue(counterState);
 
       return <h5>{count}</h5>
  }
 
  function Actions(){
       let [state, setCount] = useStore(counterState);
 
       let increment = ()=> setCounter(state + 1);
       let decrement = ()=> setCounter(state - 1);
 
       return <>
           <button onClick={increment}> + </button>
           <button onClick={decrement}> - </button>
       </>
  }

useSelector :

Returns a tuple where the first element is the value of state and the second element is a setter function that will update the value of the given state when called. Using useSelector, components can subscribe to specific updates in a Non-primitive stateInstance. Note that a useSelector will listen to all updates on the store regardless of the selector (subscribed slice of the state) provided if the setter function was called on the same component as the useSelector.

This hook can only be used with non-primitive state values

  function useSelector<T>(stateInstance: StoreInstance<T>, selector: SelectorType<T>)
  : [T, Dispatch<T>];

• stateInstance : an instance returned by createStore
• selector : A map representing the state structure with boolean values. By default every key is set to false until specified. If the value of a key is true, the component automatically subscribe to the selective update.
  
  

Example

  import { useSelector, createStore} from 'react-cargo';
 
  let counterState = createStore({key :'counter',state : {counter : 0}});
 
  function Counter(){ 
    return (
       <>
          <ViewCount/>
          <Actions/>
       </>
    )
  }
 
  function ViewCount(){
       let [counter] = useSelector(counterState,{counter : true});
 
       return <h5>{counter.count}</h5>
  }
 
  function Actions(){
       let [ state , setCount] = useSelector(counterState,{counter : true});
 
       let increment = ()=> setCount({counter : state.counter + 1});
       let decrement = ()=> setCount({counter : state.counter - 1});
 
       return <>
           <button onClick={increment}> + </button>
           <button onClick={decrement}> - </button>
       </>
  }
 

Methods

createStore :

Create a new stateInstance

function createStore<T>({ key, state, }: {
    key: string;
    state: T;
}): StoreInstance<T>;

• key : A unique string used to identify a stateInstance internally.
• state : The initial value of the stateInstance
  
  

Creating Custom State Handlers

When creating a store using createStore, it returns a getter ( get ) and setter ( set ). This can be used to create a custom handler to manipulate state which can be used to seperate concerns from components. The idea is to separate state logic from a component. However, it should be noted that get doesn't subscribe to any state change, it returns the latest store values only when called.

For example :

counter.cargo.js

  import { createStore } from 'react-cargo';

  export const counterState = createStore({
    key : 'counter',
    state : {
      counter :  0
    }
  });

  //setter syntax 1 - with prevState
  export const handleIncrement = ()=> {
    counterState.set(prevState=>({ counter : prevState.counter + 1}));
  }
  //setter syntax 2 - without prevState
  export const handleDecrement = ()=> {
     let { counter } = counterState.get();

    counterState.set({ counter : counter - 1});
  }

This can be used in a component as :

App.js

import { counterState, handleIncrement, handleDecrement } from './counter.cargo.js';

export function App() {
  return (
    <div className="App">
        <CountView />
        <Actions />
    </div>
  );
}

function CountView() {
  let [state] = useSelector(counterState,  { counter: true });
  return <p>{state.counter}</p>;
}

function Actions() {
  return (
    <p>
        <button
          type="button"
          style={{ width: 50 }}
          onClick={handleIncrement}
        >
          +
        </button>
        <button
          type="button"
          style={{ width: 50 }}
          onClick={handleDecrement}
        >
          -
        </button>
    </p>
  );
}

LICENSE

Licensed under ISC