Class RESTSerializer

public

⚠️ This is LEGACY documentation for a feature that is no longer encouraged to be used. If starting a new app or thinking of implementing a new adapter, consider writing a Handler instead to be used with the RequestManager

Normally, applications will use the RESTSerializer by implementing the normalize method.

This allows you to do whatever kind of munging you need and is especially useful if your server is inconsistent and you need to do munging differently for many different kinds of responses.

See the normalize documentation for more information.

Across the Board Normalization

There are also a number of hooks that you might find useful to define across-the-board rules for your payload. These rules will be useful if your server is consistent, or if you're building an adapter for an infrastructure service, like Firebase, and want to encode service conventions.

For example, if all of your keys are underscored and all-caps, but otherwise consistent with the names you use in your models, you can implement across-the-board rules for how to convert an attribute name in your model to a key in your JSON.

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 import RESTSerializer from '@ember-data/serializer/rest';
 import { underscore } from '<app-name>/utils/string-utils';

 export default class ApplicationSerializer extends RESTSerializer {
   keyForAttribute(attr, method) {
     return underscore(attr).toUpperCase();
   }
 }

You can also implement keyForRelationship, which takes the name of the relationship as the first parameter, the kind of relationship (hasMany or belongsTo) as the second parameter, and the method (serialize or deserialize) as the third parameter. @mainName @ember-data/serializer/rest @tag main

Show:

modelClass
Object
resourceHash
Object
returns
Object

Returns the resource's attributes formatted as a JSON-API "attributes object".

http://jsonapi.org/format/#document-resource-object-attributes

store
Store
typeClass
Model
payload
Object
id
(String|Number)
returns
Object
json The deserialized errors

extractErrors is used to extract model errors when a call to Model#save fails with an InvalidError. By default Ember Data expects error information to be located on the errors property of the payload object.

This serializer expects this errors object to be an Array similar to the following, compliant with the https://jsonapi.org/format/#errors specification:

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{
  "errors": [
    {
      "detail": "This username is already taken!",
      "source": {
        "pointer": "data/attributes/username"
      }
    }, {
      "detail": "Doesn't look like a valid email.",
      "source": {
        "pointer": "data/attributes/email"
      }
    }
  ]
}

The key detail provides a textual description of the problem. Alternatively, the key title can be used for the same purpose.

The nested keys source.pointer detail which specific element of the request data was invalid.

Note that JSON-API also allows for object-level errors to be placed in an object with pointer data, signifying that the problem cannot be traced to a specific attribute:

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{
  "errors": [
    {
      "detail": "Some generic non property error message",
      "source": {
        "pointer": "data"
      }
    }
  ]
}

When turn into a Errors object, you can read these errors through the property base:

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{{#each @model.errors.base as |error|}}
  <div class="error">
    {{error.message}}
  </div>
{{/each}}

Example of alternative implementation, overriding the default behavior to deal with a different format of errors:

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import JSONSerializer from '@ember-data/serializer/json';

export default class PostSerializer extends JSONSerializer {
  extractErrors(store, typeClass, payload, id) {
    if (payload && typeof payload === 'object' && payload._problems) {
      payload = payload._problems;
      this.normalizeErrors(typeClass, payload);
    }
    return payload;
  }
}
modelClass
Object
resourceHash
Object
returns
String

Returns the resource's ID.

store
Store
modelClass
Model
payload
Object

extractMeta is used to deserialize any meta information in the adapter payload. By default Ember Data expects meta information to be located on the meta property of the payload object.

Example

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import JSONSerializer from '@ember-data/serializer/json';

export default class PostSerializer extends JSONSerializer {
  extractMeta(store, typeClass, payload) {
    if (payload && payload.hasOwnProperty('_pagination')) {
      let meta = payload._pagination;
      delete payload._pagination;
      return meta;
    }
  }
}
relationshipModelName
Object
relationshipHash
Object
relationshipOptions
Object
returns
Object

Returns a polymorphic relationship formatted as a JSON-API "relationship object".

http://jsonapi.org/format/#document-resource-object-relationships

relationshipOptions is a hash which contains more information about the polymorphic relationship which should be extracted:

  • resourceHash complete hash of the resource the relationship should be extracted from
  • relationshipKey key under which the value for the relationship is extracted from the resourceHash
  • relationshipMeta meta information about the relationship
relationshipModelName
Object
relationshipHash
Object
returns
Object

Returns a relationship formatted as a JSON-API "relationship object".

http://jsonapi.org/format/#document-resource-object-relationships

modelClass
Object
resourceHash
Object
returns
Object

Returns the resource's relationships formatted as a JSON-API "relationships object".

http://jsonapi.org/format/#document-resource-object-relationships

key
String
method
String
returns
String
normalized key

keyForAttribute can be used to define rules for how to convert an attribute name in your model to a key in your JSON.

Example

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import JSONSerializer from '@ember-data/serializer/json';
import { underscore } from '<app-name>/utils/string-utils';

export default class ApplicationSerializer extends JSONSerializer {
  keyForAttribute(attr, method) {
    return underscore(attr).toUpperCase();
  }
}
key
String
kind
String
`belongsTo` or `hasMany`
returns
String
normalized key

keyForLink can be used to define a custom key when deserializing link properties.

key
String
typeClass
String
method
String
returns
String
normalized key

keyForPolymorphicType can be used to define a custom key when serializing and deserializing a polymorphic type. By default, the returned key is ${key}Type.

Example

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 import RESTSerializer from '@ember-data/serializer/rest';

 export default class ApplicationSerializer extends RESTSerializer {
   keyForPolymorphicType(key, relationship) {
     let relationshipKey = this.keyForRelationship(key);

     return 'type-' + relationshipKey;
   }
 }
key
String
typeClass
String
method
String
returns
String
normalized key

keyForRelationship can be used to define a custom key when serializing and deserializing relationship properties. By default JSONSerializer does not provide an implementation of this method.

Example

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  import JSONSerializer from '@ember-data/serializer/json';
  import { underscore } from '<app-name>/utils/string-utils';

  export default class PostSerializer extends JSONSerializer {
    keyForRelationship(key, relationship, method) {
      return `rel_${underscore(key)}`;
    }
  }
key
String
returns
String
the model's modelName

Dasherizes the model name in the payload

typeClass
Model
hash
Object
returns
Object

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 Model class), the property where the hash was originally found, and the hash to normalize.

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

Example

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import JSONSerializer from '@ember-data/serializer/json';
import { underscore } from '<app-name>/utils/string-utils';
import { get } from '@ember/object';

export default class ApplicationSerializer extends JSONSerializer {
  normalize(typeClass, hash) {
    let fields = typeClass.fields;

    fields.forEach(function(type, field) {
      let payloadField = underscore(field);
      if (field === payloadField) { return; }

      hash[field] = hash[payloadField];
      delete hash[payloadField];
    });

    return super.normalize(...arguments);
  }
}
typeClass
Model
hash
Object
returns
Object

The normalize method is used to convert a payload received from your external data source into the normalized form store.push() expects. You should override this method, munge the hash and return the normalized payload.

Example:

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Serializer.extend({
  normalize(modelClass, resourceHash) {
    let data = {
      id:            resourceHash.id,
      type:          modelClass.modelName,
      attributes:    resourceHash
    };
    return { data: data };
  }
})

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

normalizeQueryResponse, normalizeFindManyResponse, and normalizeFindHasManyResponse delegate to this method by default.

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is createRecord

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is deleteRecord

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is findAll

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is findBelongsTo

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is findHasMany

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is findMany

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is findRecord

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is queryRecord

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is query

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

The normalizeResponse method is used to normalize a payload from the server to a JSON-API Document.

http://jsonapi.org/format/#document-structure

Example:

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Serializer.extend({
  normalizeResponse(store, primaryModelClass, payload, id, requestType) {
    if (requestType === 'findRecord') {
      return this.normalize(primaryModelClass, payload);
    } else {
      return payload.reduce(function(documentHash, item) {
        let { data, included } = this.normalize(primaryModelClass, item);
        documentHash.included.push(...included);
        documentHash.data.push(data);
        return documentHash;
      }, { data: [], included: [] })
    }
  }
});

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

normalizeUpdateRecordResponse, normalizeCreateRecordResponse and normalizeDeleteRecordResponse delegate to this method by default.

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

normalizeQueryResponse and normalizeFindRecordResponse delegate to this method by default.

Available since v1.13.0

store
Store
primaryModelClass
Model
payload
Object
id
String|Number
requestType
String
returns
Object
JSON-API Document

Called by the default normalizeResponse implementation when the type of request is updateRecord

modelName
String
returns
String

You can use payloadKeyFromModelName to override the root key for an outgoing request. By default, the RESTSerializer returns a camelized version of the model's name.

For a model called TacoParty, its modelName would be the string taco-party. The RESTSerializer will send it to the server with tacoParty as the root key in the JSON payload:

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{
  "tacoParty": {
    "id": "1",
    "location": "Matthew Beale's House"
  }
}

For example, your server may expect dasherized root objects:

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import RESTSerializer from '@ember-data/serializer/rest';
import { dasherize } from '<app-name>/utils/string-utils';

export default class ApplicationSerializer extends RESTSerializer {
  payloadKeyFromModelName(modelName) {
    return dasherize(modelName);
  }
}

Given a TacoParty model, calling save on it would produce an outgoing request like:

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{
  "taco-party": {
    "id": "1",
    "location": "Matthew Beale's House"
  }
}
store
Store
payload
Object

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.

snapshot
Snapshot
options
Object
returns
Object
json

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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import Model, { attr, belongsTo } from '@ember-data/model';

export default class CommentModel extends Model {
  @attr body;
  @belongsto('user') author;
}

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 (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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import JSONSerializer from '@ember-data/serializer/json';

export default class PostSerializer extends JSONSerializer {
  serialize(snapshot, options) {
    let 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.

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import JSONSerializer from '@ember-data/serializer/json';
import { singularize } from '<app-name>/utils/string-utils';

export default class ApplicationSerializer extends JSONSerializer {
  serialize(snapshot, options) {
    let json = {};

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

    snapshot.eachRelationship((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(singularize(name)) + "_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.serialize first and make the tweaks on the returned JSON.

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import JSONSerializer from '@ember-data/serializer/json';

export default class PostSerializer extends JSONSerializer {
  serialize(snapshot, options) {
    let json = super.serialize(...arguments);

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

    return json;
  }
}
snapshot
Snapshot
options
Object
returns
Object

The serialize method is used when a record is saved in order to convert the record into the form that your external data source expects.

serialize takes an optional options hash with a single option:

  • includeId: If this is true, serialize should include the ID in the serialized object it builds.

Example:

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Serializer.extend({
  serialize(snapshot, options) {
    let json = {
      id: snapshot.id
    };

    snapshot.eachAttribute((key, attribute) => {
      json[key] = snapshot.attr(key);
    });

    snapshot.eachRelationship((key, relationship) => {
      if (relationship.kind === 'belongsTo') {
        json[key] = snapshot.belongsTo(key, { id: true });
      } else if (relationship.kind === 'hasMany') {
        json[key] = snapshot.hasMany(key, { ids: true });
      }
    });

    return json;
  },
});
snapshot
Snapshot
json
Object
key
String
attribute
Object

serializeAttribute can be used to customize how attr properties are serialized

For example if you wanted to ensure all your attributes were always serialized as properties on an attributes object you could write:

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import JSONSerializer from '@ember-data/serializer/json';

export default class ApplicationSerializer extends JSONSerializer {
  serializeAttribute(snapshot, json, key, attributes) {
    json.attributes = json.attributes || {};
    super.serializeAttribute(snapshot, json.attributes, key, attributes);
  }
}
snapshot
Snapshot
json
Object
relationship
Object

serializeBelongsTo can be used to customize how belongsTo properties are serialized.

Example

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import JSONSerializer from '@ember-data/serializer/json';

export default class PostSerializer extends JSONSerializer {
  serializeBelongsTo(snapshot, json, relationship) {
    let key = relationship.key;
    let belongsTo = snapshot.belongsTo(key);

    key = this.keyForRelationship ? this.keyForRelationship(key, "belongsTo", "serialize") : key;

    json[key] = !belongsTo ? null : belongsTo.record.toJSON();
  }
}
snapshot
Snapshot
json
Object
relationship
Object

serializeHasMany can be used to customize how hasMany properties are serialized.

Example

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import JSONSerializer from '@ember-data/serializer/json';

export default class PostSerializer extends JSONSerializer {
  serializeHasMany(snapshot, json, relationship) {
    let key = relationship.key;
    if (key === 'comments') {
      return;
    } else {
      super.serializeHasMany(...arguments);
    }
  }
}
hash
Object
typeClass
Model
snapshot
Snapshot
options
Object

You can use this method to customize how a serialized record is added to the complete JSON hash to be sent to the server. By default the JSON Serializer does not namespace the payload and just sends the raw serialized JSON object. If your server expects namespaced keys, you should consider using the RESTSerializer. Otherwise you can override this method to customize how the record is added to the hash. The hash property should be modified by reference.

For example, your server may expect underscored root objects.

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import RESTSerializer from '@ember-data/serializer/rest';
import { decamelize } from '<app-name>/utils/string-utils';

export default class ApplicationSerializer extends RESTSerializer {
  serializeIntoHash(data, type, snapshot, options) {
    let root = decamelize(type.modelName);
    data[root] = this.serialize(snapshot, options);
  }
}
snapshot
Snapshot
json
Object
relationship
Object

You can use this method to customize how polymorphic objects are serialized. Objects are considered to be polymorphic if { polymorphic: true } is pass as the second argument to the belongsTo function.

Example

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import JSONSerializer from '@ember-data/serializer/json';

export default class CommentSerializer extends JSONSerializer {
  serializePolymorphicType(snapshot, json, relationship) {
    let key = relationship.key;
    let belongsTo = snapshot.belongsTo(key);

    key = this.keyForAttribute ? this.keyForAttribute(key, 'serialize') : key;

    if (!belongsTo) {
      json[key + '_type'] = null;
    } else {
      json[key + '_type'] = belongsTo.modelName;
    }
  }
}
snapshot
Snapshot
key
String
relationship
RelationshipSchema
returns
Boolean
true if the hasMany relationship should be serialized

Check if the given hasMany relationship should be serialized

By default only many-to-many and many-to-none relationships are serialized. This could be configured per relationship by Serializer's attrs object.