Behave-immutable NPM

behave-immutable

An immutable data store that keeps state history

In most cases when you want to update a model/store, you will also want access to it's previous states, in a lot of frameworks this is something you have to design on your own even though this is how a model should behave.

behave-immutable depends on Facebook's Immutable library under the hood, when you pull state from the stack it will return you an instance of Immutable.

Install

npm install --save behave-immutable

Usage

// anything passed to constructor will be set as first state
const immutable = new BehaveImmutable({ some: 'value' });

// setting state
immutable.set({ another: 'value' });
immutable.toJS(); // => { some: 'value', another: 'value' }
immutable.at(1).toJS(); // => { some: 'value' }

// resetting state
immutable.set({ another: 'value' }, { reset: true });
immutable.toJS(); // => { another: 'value' }
immutable.at(1).toJS(); // => { some: 'value' }


// replacing state
immutable.set({ another: 'value' }, { reset: true, replace: true });
immutable.toJS(); // => { another: 'value' }
immutable.at(1); // => undefined
immutable.count(); // => 1

// working with state from the stack
let currentState = immutable.get(); // => latest state

let removeLastState = immutable.pop(); // => latest state, removing from stack

let removeFirstState = immutable.shift(); // => first state, removing from stack

let atIndex = immutable.at(someIndex); // => copy of state at index, non-destructive

let range = immutable.range(start, end); // => array of states in range (including end index)

immutable.purge(); // => empties the stack

// sugar methods to transform latest state
immutable.toJS(); // => { some: 'value', another: 'value' }

immutable.toJSON(); // => { "some": "value", "another": "value" }

immutable.serialize(); // => "some=value&another=value"