Instate

Instate is an application state manager built for React and based loosely on the popular Redux library. At it's core, Instate is a single, global application state that you map to your components.

For example:

import React, { Component } from "react":
import { connect, state } from "instate";

/* Set out initial, global state */
state.setState({ 
    user: {
        isLoggedIn: false
    }
});

/* Map the global state "user" property to the local application state property "user" */
@connect({ user: "user" })
class App extends Component {
    render() {
        if(this.state.user.isLoggedIn) {
            return (<p>Hello there user!</p>);
        } else {
            return (<p>Hello there. Please login.</p>);
        }
    }
}

Any updates to the local state will then be proxied onto the global state. Simple as that. For more detailed examples, take a look in the examples/ directory or to see a live version, visit the todo app or a simple login flow app.

Features

• Directly connect your React components to the global state with zero hassle.
• Exported state singleton which can be imported anywhere and always reference the global state.
• Framework/library agnostic. Instate comes with React bindings but can work with any library.
• State mutations are just descriptions of how the state changes. This means they can be logged, reversed and redone like Redux.
• Lightweight at 8KB minified, 2.5KB gzipped.
• Extremely simple API which can be learned in minutes without any complex underlying concepts.

Installation

Install via npm: (link)

$ npm install --save instate

Docs

@connect( stateMap [, targetState ] ) decorator

This is an ES7 decorator that must be called on the React component you want to connect to the global state. The stateMap parameter is a map of localStatePropName: globalStateKeyPath. For example, if you wanted the user.name key path in the global state to be under the userName property on the local, component state you would @connect({ userName: "user.name" }). The targetState parameter is the state to proxy the changes to and from the local, component state. Defaults to the global state but Instate allows you to pass in your own State if you feel like managing it yourself.

state State instance

The global application State object. This can be imported from anywhere in the application and you will always be referencing the same, global state. For methods associated with this object, see the State instance methods.

new State( [ initialState:Object ] ) class

Create a new State object with initialState as it's initial state.

State#get( keyPath:String )

Get a value from the state object by key path. Example:

state.setState({
    foo: {
        bar: "baz"
    }
});

state.get("foo.bar") // "baz"

State#update( keyPath:String, value:Any [, create:Boolean ] )

Update a value in the state at the given key path. Note: The state should never be without the use of either setState, delete or this function. The create flag describes whether the update creates the path as it traverses the tree. Think mkdir -p. Example:

state.update("foo.bar", "baz");
state.get("foo.bar"); // "baz"

State#subscribe( keyPath:String, listener:Function )

Subscribe to updates on a key path. This function is fired any time a value of it's children are change. For example, if foo.bar.baz changes, foo and foo.bar's listeners will fire. The listener function has the following signature: (path, value, oldValue, state).

State#unsubscribe( keyPath:String [, listener:Function ] )

Unsubscribe from updates on a key path. If no listener is passed, all listeners under the keypath are removed otherwise just the listener itself passed will be removed.

State#getState( state:Object ) and State#setState( state:Object )

Get and set the root state.

State#delete( keyPath:String )

Delete a value from the state at a given key path. Note: Any subscriptions for the particular value will be notified that the value has changed to undefined however the key will be fully removed from the parent object.

Credits & License

Author: Adrian Cooney [email protected]

License: MIT