Ember-computed-enum NPM

ember-computed-enum

ember-computed-enum translates an field containing a "magic number" into it's human-readable analogue, and provides named properties to easily check for any given state.

Installation

ember install ember-computed-enum

Usage

The addon can be used in two different ways.

For full functionality, use the addon...

as a Mixin (with `enumNameIsValue` properties)

import { computedEnumMixin } from 'ember-computed-enum';

myEnumValues = ['foo', 'bar', 'baz'];

MyClassWithAnEnum = Ember.Object.extend(
  computedEnumMixin('myEnum', 'enumValRaw', myEnumValues),
  {
    // ... your other properties
  }
);

o = MyClassWithAnEnum.create({ enumValRaw: 0 });
o.get('enumValRaw'); // -> 0
o.get('myEnum');  // -> 'foo'

o.get('myEnumIsFoo');  // -> true
o.get('myEnumIsBar');  // -> false
o.get('myEnumIsBaz');  // -> false

In cases where the 'enumNameIsValue` properties aren't needed, the addon can also be used...

as a simple property (without `enumNameIsValue` properties)

import { computedEnum } from 'ember-computed-enum';

myEnumValues = ['foo', 'bar', 'baz'];

MyClassWithAnEnum = Ember.Object.extend({
  myEnum: computedEnum('enumValRaw', myEnumValues)
});


o = MyClassWithAnEnum.create({ enumValRaw: 0 });
o.get('enumValRaw'); // -> 0
o.get('myEnum');  // -> 'foo'

o.get('myEnumIsFoo');  // -> undefined
o.get('myEnumIsBar');  // -> undefined
o.get('myEnumIsBaz');  // -> undefined

Models

The addon works with any Ember Objects, including ember-data models. To use with Ember models, store the raw value of the enum in one field:

// app/models/person.js

import DS from 'ember-data';

export default DS.Model.extend({
  name: DS.attr('string'),
  genderCode: DS.attr('number')
});

Then add a computed enum that references the raw value:

// app/models/person.js

import DS from 'ember-data';

import { computedEnumMixin } from 'ember-computed-enum';

export default DS.Model.extend(
  computedEnumMixin('gender', 'genderCode', ['male', 'female', 'other']),
  {
    name: DS.attr('string'),
    genderCode: DS.attr('number')
  }
);

If you want to assign the raw value to a different fieldname than that assigned by the API, you can create a simple Serializer. For example, if our API returns a gender code in a field named gender, we could make Person.gender contain the decoded value and store the raw, coded version by creating a serializer like this:

app/serializers/person.js

import DS from 'ember-data';

export default DS.JSONAPISerializer.extend({
  attrs: {
    genderCode: 'gender'  // map the API's "gender" field to the "genderCode" field on the model
  }
});

Custom Enum Values

By default, ember-computed-enum assumes enum values are zero-indexed integers (0, 1, 2...), but other values can be used by passing in an object mapping enum names to values. For example, if "gender" were coded as 'm', 'f', and 'o', your model might look like:

// app/models/person.js

import DS from 'ember-data';

import { computedEnumMixin } from 'ember-computed-enum';

genderEnum = {'male': 'm', 'female', 'f', 'other': 'o'};

export default DS.Model.extend(
  computedEnumMixin('gender', 'genderCode', genderEnum),
  {
    name: DS.attr('string'),
    genderCode: DS.attr('number')
  }
);

The rest of this README outlines the details of collaborating on this Ember addon.