A tiny (265 byte) utility to create state machine components using two pure functions.
The API is a single function that accepts 2 pure functions as arguments:
stateMachineComponent(reduce, render)The first function, reduce(), takes in the current state and applies an action to it, similar to a reducer in Redux:
// Reduce is a redux-style reducer
function reduce(state, action) {
// actions are like Redux Standard Actions:
let { type, data, props } = action
return { } // just return the new state
}The second function, render(), is a pure functional component that gets passed the current state instead of props, and a second argument action() - a function that creates a bound dispatcher for the given action type:
// Render is a functional component with little twist
function render(state, action) {
// action() creates a dispatcher for an action type:
return <button onClick={ action('TYPE') } />
}// Remember:
// `state` is the current state.
// `action` is a redux standard action.
function reduce(state, action) {
switch (action.type) {
case '@@INIT': return { count: 0 }
case 'ADD': return { count: state.count+1 }
}
}
function render(state, action) {
return (
<div class="counter">
Current count: {state.count}
<button onClick={action('ADD')}>Add 1</button>
</div>
)
}
stateMachineComponent(reduce, render)const ToDos = stateMachineComponent(
// (state, action)
({ todos, text }, { type, data, props }) => {
switch (type) {
case '@@INIT':return { todos: props.todos || [], text: '' };
case 'ADD': return { todos: todos.concat(text), text: '' };
case 'TEXT': return { text: data.target.value };
}
},
// state, action(type)
({ todos, text }, action) => (
<div>
<h2>State Machine ToDos</h2>
<ul>{todos.map( todo => <li>{todo}</li> )}</ul>
<form onSubmit={action('ADD')}>
<input value={text} onInput={action('TEXT')} />
</form>
</div>
)
);