Ember Cerebral / ember-cerebraljs

Enhanced state management for complex Ember apps using Cerebral.

Why?

If you've had success with Ember's data down, actions up pattern, think of Cerebral as turning that pattern up to 11. In cerebral, all state lives in one central state store and flows in one direction from the top of your component tree to the bottom. Additionally, state changes do not happen by mutating models or component props via two way bindings. They are externalized to chains of functions, called signals, that may also perform asynchronous requests (ajax, etc).

Isolating state, updating it with small, simple functions, and embracing one way dataflow improves your ability to reason about your application as it scales in size and complexity, especially with tools like the Cerebal debugger.

In short, Ember Cerebral brings the best of the Flux/React and Ember communities together into one package.

Installation

• ember install ember-cerebraljs

Usage

Check out the example TodoMVC app. (TodoMVC app - is old addon version ember-cerebral)

Expose Cerebral state to your component using the CerebralMixin and define a props[] array of component mapping properties to their location in the cerebral store:

// in component x-foo.js

import {CerebralMixin} from 'ember-cerebraljs';

export default Ember.Component.extend(CerebralMixin, {
  props: [
      'userName:path.to.cerebral.userName',
      'petName:@someDynamicAtrributeNameWithPath'
  ]
});

State is available as props on the component (and routes):

// in component x-foo.js

excitedUserName: computed('userName', function() {
  return `My name is ${this.get('userName')}`;
})


this.set('someDynamicAtrributeNameWithPath','path.to.cerebral.petName');
this.get('petName') // -> resolved to 'path.to.cerebral.petName'

Trigger signals to change state:

actions: {
  buttonClicked() {
    this.sendSignal('buttonClicked');
  }
}

Connect approach for components:

import Component from '@ember/component';
import {connect} from 'ember-cerebraljs';

// list of read-only state binded props
const props = [
    'count',
    'componentPropertyName:stateProperty'
];

// list fo signals to bind to actions
const signals = [
    'onIncrease',
    'actionName:signalName'
];

export default connect(props, signals, Component);

Component template

{{count}} <button {{action 'onIncrease'}}>onIncrease</button>

App state located in:

app/states/application.js

App reducers / signals located in:

app/signals/application.js

App actions located in:

app/actions/application.js

Cerebral config located in:

app/services/cerebraljs.js

Actions resolving rules (for string action)

//example:

{
  signals: {
    user: {
      management: {
        save: ['showProgressBar','save', 'hideProgressBar']
      }
    }
  }
}

// `showProgressBar`, `save`, `hideProgressBar` will be resolved by this logic:

actions.user.management.save[actionName]
  else
actions.user.management[actionName]
  else
actions.user[actionName]
  else
actions[actionName]

New namespaces:

const {
    CerebralService,
    SignalsObject,
    StateObject,
    ActionsObject,
    CerebralMixin,
    connect
} from 'ember-cerebraljs';

/*
CerebralMixin - computed-props based mixin [props]
connect - component connector connect([props],[signals],component);
SignalsObject - signals object, SignalsObject.create({signals});
ActionsObject - actions object, ActionsObject.create({actions});
StateObject - state object, StateObject.create({state});
CerebralService - main service & initializer, CerebralService.extend({state,signals});
*/

@cerebral/baobab
baobab
cerebral
emmett
eventemitter3
function-tree

Example:

import Component from '@ember/component';
import { connect } from 'ember-cerebraljs';

export default connect(
  ['count:current.user.age'],
  ['onIncrease'],
  Component.extend({
    layout: hbs`{{count}} <button {{action 'onIncrease'}}>onIncrease</button>`
  })
)

Hold ON!

What about dynamic paths and signals bindings?

• it's easy.

import Component from '@ember/component';
import { connect } from 'ember-cerebraljs';

export default connect(
  ['count:@componentAttributePath'],
  ['onIncrease:@componentAttributeSignal'],
  Component.extend({
    layout: hbs`{{count}} <button {{action 'onIncrease'}}>onIncrease</button>`
  })
)

---

Thanks

Thanks to Toran Billups (@toranb) who's screencast on ember-redux inspired this integration.

Thanks to Brian Fitch (@bfitch) for first addon version ember-cerebral

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For more information on using ember-cli, visit https://ember-cli.com/.