Concurrency with i18n driven

components.async-button.js

import Ember from 'ember';
export default Ember.Component.extend({
  tagName: '',
});

components.button-table.js

import Ember from 'ember';

export default Ember.Component.extend({
  xs: ["", "success", "secondary", "alert"],
  ys: ["", "active", "disabled"],
});

controllers.application.js

import Ember from 'ember';
import { task, timeout } from 'ember-concurrency';

export default Ember.Controller.extend({
  myTask: task(function * () {
    yield timeout(1500);
    return { username: "machty" };
  }).restartable(),
  
  otherTask: task(function * () {
    yield timeout(1500);
    return { username: "trekkles" };
  }).restartable(),
});

helpers.state-for.js

import Ember from 'ember';
import { task, timeout } from 'ember-concurrency';
const { computed, inject } = Ember;

const State = Ember.Object.extend({
  tagName: '',
  
  t: null,
  task: null,
  state: computed.or('task.state', '_defaultState'),
  _defaultState: 'idle',

  init() {
    this._super();
    this.perform = Ember.run.bind(this, '_perform');
  },
  
  _perform(...args) {
    // TODO: how to compose "performability" when
    // we decorate the underlying task with timeouts?
    if (!this.get('task.isRunning')) {
      this.get('_internalTask').cancelAll();
      this.get('_internalTask').perform(...args);
    }
  },
  
  isActive: computed.bool('_lastTaskInstance.isRunning'),
  
  isDisabled: computed('_lastTaskInstance', 'task.last.isRunning', function() {
    let lastTaskInstance = this.get('_lastTaskInstance');
    let last = this.get('task.last');
    return last && last.get('isRunning') && last !== lastTaskInstance;
  }),
  
  successValue: null,
  isSuccess: false,
  cooldown: 3000,
  _internalTask: task(function * (...args) {
    let ti = this.get('task').perform(...args);
    this.set('_lastTaskInstance', ti);
    let value = yield ti;
    
    try {
      this.set('isSuccess', true);
      this.set('successValue', value);
      yield timeout(this.get('cooldown'));
    } finally {
      this.set('isSuccess', false);
      this.set('successValue', null);
    }
  }),
  _lastTaskInstance: null,
});

export default Ember.Helper.extend({
  compute(_, options) {
    return State.create({
      task: options.task,
      t: options.t,
    });
  },
});

helpers.text-for.js

import Ember from 'ember';
import { task, timeout } from 'ember-concurrency';
const { computed, inject } = Ember;

export default Ember.Helper.extend({
  i18n: inject.service(),
  _stashedState: null,
  
  state: null,
  t: null,
  
  default: computed('state.state', 'state.isDisabled', 'state.isSuccess', function() {
    let state = this.get('state');
    if (state.get('isSuccess')) {
      return this._findFirstTranslation([
        'success',
        'idle'
      ], { value: state.get('successValue') });
    } else if (state.get('isDisabled')) {
      return this._findFirstTranslation(['idle']);
    } else {
      return this._findFirstTranslation([
        state.get('state'),
        'idle'
      ]);
    }
  }),

  idleText: computed(function() {
    return this._findFirstTranslation(['idle']);
  }),
      
  _findFirstTranslation(keys, data = {}) {
    let prefix = this.get('t') || 'button.default';
    let i18n = this.get('i18n');
    for (let i = 0; i < keys.length; ++i) {
      let key = `${prefix}.${keys[i]}`;
      if (i18n.exists(key)) {
        return i18n.t(key, data);
      }
    }
    
    // TODO: better messaging
    return `Missing Translations (${keys.join(', ')})`;
  },
  
  compute(_, { state, t }) {
    this.set('state', state);
    this.set('t', t);
    return this;
  },
});

locales.en.translations.js

export default {
  'button': {
    'default': {
      'idle': 'Go',
      'running': 'Please Wait...',
    },
    'add_user': {
      'idle': 'Add a user',
      'running': 'Adding User...',
      'success': 'Added User {{value.username}}!',
    },
    'save_profile': {
      'idle': 'Save Profile',
      'running': 'Saving Profile...',
    }
  },
  'loading-banner': {
    'idle': 'Add a user',
    'running': 'Adding User...',
    'success': 'Added User {{value.username}}!',
  }
};

styles.app.css

body {
  margin: 12px 16px !important;
}

.button {
  position: relative;
}

.button.active::before {
  content: ' ';
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border: 6px solid rgba(255,255,255,0.4);
}

table .button {
  width: 100%;
  margin: 0;
}

templates.application.hbs

<h2>Tasks + i18n</h2>

<p>
  Robust web apps feature most/all the following button/UI states:
</p>

{{button-table}}

<p>
  Here's a stab at an API to get a lot of the above
  states for free using tasks and ember-i18n.
</p>

<div class="expanded button-group">
  {{async-button t='button.add_user' task=myTask}}
  {{async-button t='button.add_user' class='secondary' 
                 task=myTask}}
  {{#async-button t='button.save_profile' task=myTask as |h|}}
    LOL, {{h.text.default}}
  {{/async-button}}
</div>

<div class="expanded button-group">
  {{async-button t='button.save_profile' task=otherTask}}
  {{async-button t='button.save_profile' class='secondary' 
                 task=otherTask}}
  {{async-button t='button.save_profile' task=otherTask}}
</div>

<p>
  Some niceties / possible conventions emerge:
</p>

<ul>
  <li>
    An "active" button is the one that you clicked that kicked off a task
  </li>
  <li>
    A "disabled" button is one that can't be clicked right now because
    the task that it would perform is already running (technically, the
    only difference between an "active" and "disabled" button is that
    you clicked the "active" one)
  </li>
  <li>
    Built-in cooldown periods to display success messages (and the success result from the task is passed to the success translation template)
  </li>
  <li>
    Graceful fallback to the most specific
    translation that describes the success action.
  </li>
</ul>

<h3>Composition</h3>

<p>
  The behavior of the buttons above is encapsulated
  in the async-button component, which itself
  delegates most of its "work" and configuration
  to two helpers: <strong>state-for</strong>
  and <strong>text-for</strong>
</p>

<h4>state-for</h4>

<p>
  This helper wraps a Task and exposes
  additional state that's useful for driving
  UI. In particular, the "cooldown" behavior
  is essentially a decoration on top of the
  underlying task, and the combined state
  of the task and various decorations is
  provided within the object returned from
  state-for. (I just now realized that this
  overlaps with the terminology in
  ember-state-services; pretend this has
  a different name).
</p>

<h4>text-for</h4>

<p>
  text-for takes a state-for object and
  translation locale path and returns a
  utility object with lots of properties
  for displaying text.
</p>

<p>
  The whole goal of all of this is to land
  on conventions that a) compose well with
  other established conventions and b) themselves
  decompose into reusable bits.
</p>













<br><br><br><br><br><br><br>
<br><br><br><br><br><br><br>

<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/foundation/6.3.0/css/foundation-flex.css">

templates.components.async-button.hbs

{{#with (state-for task=task) as |s|}}
  {{#with (text-for state=s t=t) as |text|}}
    <div class="button {{class}}
                       {{if s.isActive 'active'}} 
                       {{if s.isDisabled 'disabled'}}
                       {{if s.isSuccess 'success'}}" 
         onclick={{action s.perform}}>
      {{#if hasBlock}}
        {{yield (hash text=text)}}
      {{else}}
        {{text.default}}
      {{/if}}
    </div>
  {{/with}}
{{/with}}

templates.components.button-table.hbs

<table style="width: 100%;">
  <thead>
    <tr>
      <th></th>
      {{#each xs as |x|}}
        <th>
          {{x}}
        </th>
      {{/each}}
    </tr>
  </thead>
  
  <tbody>
  {{#each ys as |y|}}
    <tr>
      <td>{{y}}</td>

      {{#each xs as |x|}}
        <td>
          <div class="button {{x}} {{y}}">
            {{if x x 'default'}}<br>{{y}}
          </div>
        </td>
      {{/each}}
    </tr>
  {{/each}}
  </tbody>
</table>

twiddle.json

{
  "version": "0.10.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-data": "2.12.1",
    "ember-template-compiler": "2.12.0"
  },
  "addons": {
    "ember-concurrency": "latest",
    "ember-i18n": "latest"
  }
}