DS#attr()

DS.attr defines an attribute on a DS.Model. By default, attributes are passed through as-is, however you can specify an optional type to have the value automatically transformed. Ember Data ships with four basic transform types: string, number, boolean and date. You can define your own transforms by subclassing DS.Transform.

Note that you cannot use attr to define an attribute of id.

DS.attr takes an optional hash as a second parameter, currently supported options are:

• defaultValue: Pass a string or a function to be called to set the attribute to a default value if none is supplied.

Example

import DS from 'ember-data';

export default DS.Model.extend({
  username: DS.attr('string'),
  email: DS.attr('string'),
  verified: DS.attr('boolean', { defaultValue: false })
});

Default value can also be a function. This is useful it you want to return a new object for each attribute.

import DS from 'ember-data';

export default DS.Model.extend({
  username: attr('string'),
  email: attr('string'),
  settings: attr({defaultValue: function() {
    return {};
  }})
});

The options hash is passed as second argument to a transforms' serialize and deserialize method. This allows to configure a transformation and adapt the corresponding value, based on the config:

export default DS.Model.extend({
  text: DS.attr('text', {
    uppercase: true
  })
});

export default DS.Transform.extend({
  serialize: function(value, options) {
    if (options.uppercase) {
      return value.toUpperCase();
    }

    return value;
  },

  deserialize: function(value) {
    return value;
  }
})