DS.RESTSerializer#serialize()

Called when a record is saved in order to convert the record into JSON.

By default, it creates a JSON object with a key for each attribute and belongsTo relationship.

For example, consider this model:

import DS from 'ember-data';

export default DS.Model.extend({
  title: DS.attr(),
  body: DS.attr(),

  author: DS.belongsTo('user')
});

The default serialization would create a JSON object like:

{
  "title": "Rails is unagi",
  "body": "Rails? Omakase? O_O",
  "author": 12
}

By default, attributes are passed through as-is, unless you specified an attribute type (DS.attr('date')). If you specify a transform, the JavaScript value will be serialized when inserted into the JSON hash.

By default, belongs-to relationships are converted into IDs when inserted into the JSON hash.

IDs

serialize takes an options hash with a single option: includeId. If this option is true, serialize will, by default include the ID in the JSON object it builds.

The adapter passes in includeId: true when serializing a record for createRecord, but not for updateRecord.

Customization

Your server may expect a different JSON format than the built-in serialization format.

In that case, you can implement serialize yourself and return a JSON hash of your choosing.

import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serialize: function(snapshot, options) {
    var json = {
      POST_TTL: snapshot.attr('title'),
      POST_BDY: snapshot.attr('body'),
      POST_CMS: snapshot.hasMany('comments', { ids: true })
    }

    if (options.includeId) {
      json.POST_ID_ = snapshot.id;
    }

    return json;
  }
});

Customizing an App-Wide Serializer

If you want to define a serializer for your entire application, you'll probably want to use eachAttribute and eachRelationship on the record.

import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serialize: function(snapshot, options) {
    var json = {};

    snapshot.eachAttribute(function(name) {
      json[serverAttributeName(name)] = snapshot.attr(name);
    })

    snapshot.eachRelationship(function(name, relationship) {
      if (relationship.kind === 'hasMany') {
        json[serverHasManyName(name)] = snapshot.hasMany(name, { ids: true });
      }
    });

    if (options.includeId) {
      json.ID_ = snapshot.id;
    }

    return json;
  }
});

function serverAttributeName(attribute) {
  return attribute.underscore().toUpperCase();
}

function serverHasManyName(name) {
  return serverAttributeName(name.singularize()) + "_IDS";
}

This serializer will generate JSON that looks like this:

{
  "TITLE": "Rails is omakase",
  "BODY": "Yep. Omakase.",
  "COMMENT_IDS": [ 1, 2, 3 ]
}

Tweaking the Default JSON

If you just want to do some small tweaks on the default JSON, you can call super first and make the tweaks on the returned JSON.

import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  serialize: function(snapshot, options) {
    var json = this._super(snapshot, options);

    json.subject = json.title;
    delete json.title;

    return json;
  }
});