DS.RESTSerializer Class packages/ember-data/lib/serializers/rest_serializer.js:15

Called when the server has returned a payload representing multiple records, such as in response to a findAll or findQuery.

It is your opportunity to clean up the server's response into the normalized form expected by Ember Data.

If you want, you can just restructure the top-level of your payload, and do more fine-grained normalization in the normalize method.

For example, if you have a payload like this in response to a request for all posts:

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{
  "_embedded": {
    "post": [{
      "id": 1,
      "title": "Rails is omakase"
    }, {
      "id": 2,
      "title": "The Parley Letter"
    }],
    "comment": [{
      "_id": 1,
      "comment_title": "Rails is unagi"
      "post_id": 1
    }, {
      "_id": 2,
      "comment_title": "Don't tread on me",
      "post_id": 2
    }]
  }
}

You could implement a serializer that looks like this to get your payload into shape:

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App.PostSerializer = DS.RESTSerializer.extend({
  // First, restructure the top-level so it's organized by type
  // and the comments are listed under a post's `comments` key.
  extractArray: function(store, type, payload, id, requestType) {
    var posts = payload._embedded.post;
    var comments = [];
    var postCache = {};

    posts.forEach(function(post) {
      post.comments = [];
      postCache[post.id] = post;
    });

    payload._embedded.comment.forEach(function(comment) {
      comments.push(comment);
      postCache[comment.post_id].comments.push(comment);
      delete comment.post_id;
    }

    payload = { comments: comments, posts: payload };

    return this._super(store, type, payload, id, requestType);
  },

  normalizeHash: {
    // Next, normalize individual comments, which (after `extract`)
    // are now located under `comments`
    comments: function(hash) {
      hash.id = hash._id;
      hash.title = hash.comment_title;
      delete hash._id;
      delete hash.comment_title;
      return hash;
    }
  }
})

When you call super from your own implementation of extractArray, the built-in implementation will find the primary array in your normalized payload and push the remaining records into the store.

The primary array is the array found under posts.

The primary record has special meaning when responding to findQuery or findHasMany. In particular, the primary array will become the list of records in the record array that kicked off the request.

If your primary array contains secondary (embedded) records of the same type, you cannot place these into the primary array posts. Instead, place the secondary items into an underscore prefixed property _posts, which will push these items into the store and will not affect the resulting query.

Called when the server has returned a payload representing a single record, such as in response to a find or save.

It is your opportunity to clean up the server's response into the normalized form expected by Ember Data.

If you want, you can just restructure the top-level of your payload, and do more fine-grained normalization in the normalize method.

For example, if you have a payload like this in response to a request for post 1:

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{
  "id": 1,
  "title": "Rails is omakase",

  "_embedded": {
    "comment": [{
      "_id": 1,
      "comment_title": "FIRST"
    }, {
      "_id": 2,
      "comment_title": "Rails is unagi"
    }]
  }
}

You could implement a serializer that looks like this to get your payload into shape:

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App.PostSerializer = DS.RESTSerializer.extend({
  // First, restructure the top-level so it's organized by type
  extractSingle: function(store, type, payload, id, requestType) {
    var comments = payload._embedded.comment;
    delete payload._embedded;

    payload = { comments: comments, post: payload };
    return this._super(store, type, payload, id, requestType);
  },

  normalizeHash: {
    // Next, normalize individual comments, which (after `extract`)
    // are now located under `comments`
    comments: function(hash) {
      hash.id = hash._id;
      hash.title = hash.comment_title;
      delete hash._id;
      delete hash.comment_title;
      return hash;
    }
  }
})

When you call super from your own implementation of extractSingle, the built-in implementation will find the primary record in your normalized payload and push the remaining records into the store.

The primary record is the single hash found under post or the first element of the posts array.

The primary record has special meaning when the record is being created for the first time or updated (createRecord or updateRecord). In particular, it will update the properties of the record that was saved.

Normalizes a part of the JSON payload returned by the server. You should override this method, munge the hash and call super if you have generic normalization to do.

It takes the type of the record that is being normalized (as a DS.Model class), the property where the hash was originally found, and the hash to normalize.

For example, if you have a payload that looks like this:

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{
  "post": {
    "id": 1,
    "title": "Rails is omakase",
    "comments": [ 1, 2 ]
  },
  "comments": [{
    "id": 1,
    "body": "FIRST"
  }, {
    "id": 2,
    "body": "Rails is unagi"
  }]
}

The normalize method will be called three times:

• With App.Post, "posts" and { id: 1, title: "Rails is omakase", ... }
• With App.Comment, "comments" and { id: 1, body: "FIRST" }
• With App.Comment, "comments" and { id: 2, body: "Rails is unagi" }

You can use this method, for example, to normalize underscored keys to camelized or other general-purpose normalizations.

If you want to do normalizations specific to some part of the payload, you can specify those under normalizeHash.

For example, if the IDs under "comments" are provided as _id instead of id, you can specify how to normalize just the comments:

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App.PostSerializer = DS.RESTSerializer.extend({
  normalizeHash: {
    comments: function(hash) {
      hash.id = hash._id;
      delete hash._id;
      return hash;
    }
  }
});

The key under normalizeHash is just the original key that was in the original payload.

You can use this method to normalize all payloads, regardless of whether they represent single records or an array.

For example, you might want to remove some extraneous data from the payload:

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App.ApplicationSerializer = DS.RESTSerializer.extend({
  normalizePayload: function(type, payload) {
    delete payload.version;
    delete payload.status;
    return payload;
  }
});

This method allows you to push a payload containing top-level collections of records organized per type.

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{
  "posts": [{
    "id": "1",
    "title": "Rails is omakase",
    "author", "1",
    "comments": [ "1" ]
  }],
  "comments": [{
    "id": "1",
    "body": "FIRST"
  }],
  "users": [{
    "id": "1",
    "name": "@d2h"
  }]
}

It will first normalize the payload, so you can use this to push in data streaming in from your server structured the same way that fetches and saves are structured.

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:

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App.Comment = DS.Model.extend({
  title: DS.attr(),
  body: DS.attr(),

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

The default serialization would create a JSON object like:

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{
  "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.

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App.PostSerializer = DS.RESTSerializer.extend({
  serialize: function(post, options) {
    var json = {
      POST_TTL: post.get('title'),
      POST_BDY: post.get('body'),
      POST_CMS: post.get('comments').mapProperty('id')
    }

    if (options.includeId) {
      json.POST_ID_ = post.get('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.

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App.ApplicationSerializer = DS.RESTSerializer.extend({
  serialize: function(record, options) {
    var json = {};

    record.eachAttribute(function(name) {
      json[serverAttributeName(name)] = record.get(name);
    })

    record.eachRelationship(function(name, relationship) {
      if (relationship.kind === 'hasMany') {
        json[serverHasManyName(name)] = record.get(name).mapBy('id');
      }
    });

    if (options.includeId) {
      json.ID_ = record.get('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:

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{
  "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.

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App.PostSerializer = DS.RESTSerializer.extend({
  serialize: function(record, options) {
    var json = this._super(record, options);

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

    return json;
  }
});

You can use this method to customize the root keys serialized into the JSON. By default the REST Serializer sends camelized root keys. For example, your server may expect underscored root objects.

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App.ApplicationSerializer = DS.RESTSerializer.extend({
  serializeIntoHash: function(data, type, record, options) {
    var root = Ember.String.decamelize(type.typeKey);
    data[root] = this.serialize(record, options);
  }
});

You can use this method to customize how polymorphic objects are serialized. By default the JSON Serializer creates the key by appending Type to the attribute and value from the model's camelcased model name.

You can use this method to normalize the JSON root keys returned into the model type expected by your store.

For example, your server may return underscored root keys rather than the expected camelcased versions.

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App.ApplicationSerializer = DS.RESTSerializer.extend({
  typeForRoot: function(root) {
    var camelized = Ember.String.camelize(root);
    return Ember.String.singularize(camelized);
  }
});