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StateCarrierMixin

Provides support for maintaining the state properties as introduced by the api/v2/nodes/:id or api/v2/nodes/:id/nodes (V2) resources.

Server responses may contain not only data, but also state properties, which may be needed for evaluation on either client or server sides. The metadata_token, for example.

How to apply the mixin to a model​

var MyModel = Backbone.Model.extend({
  constructor: function MyModel(attributes, options) {
    Backbone.Model.prototype.constructor.apply(this, arguments);
    this
      .makeConnectable(options)
      .makeFieldsV2(options)
      .makeStateCarrier(options);
  },

  url: function () {
    var url = Url.combine(this.connector.connection.url, 'myresource');
    var query = Url.combineQueryString(
      this.getResourceFieldsUrlQuery(),
      this.getStateEnablingUrlQuery()
    );
    return Url.appendQuery(url, query);
  },

  parse: function (response, options) {
    var results = response.results || response;
    this.parseState(results, 'properties');
    return results.data.properties;
  }
});

ConnectableMixin.mixin(MyModel.prototype);
FieldsV2Mixin.mixin(MyModel.prototype);
StateCarrierMixin.mixin(MyModel.prototype);

This mixin us usually combined together with the ConnectableMixin and FieldsV2Mixin or with another cumulated mixin which includes them. This mixin includes the StateRequestorMixin and applieas it automatically.

How to use the mixin​

Get or set properties in te state object as you need them:

// Get the metadata toklen to pass it to a modification server call
var metadataToken = model.state.get('metadata_token');

// Set the metadatan token from a response of a server call
model.state.set('metadata_token', results.state.properties.metadata_token);

Simplify parsing the state properties from a standard V2 API response:

// Support retrieving the attributes when fetching either collection or model.
var results = response.results || response;
var data = results.data;
this.parseState(data, results, 'properties');

makeStateCarrier(options) : this​

Must be called in the constructor to initialize the mixin functionality. Expects the Backbone.Model or Backbone.Collection constructor options passed in.

state : Backbone.Model​

Maintains the object state properties (empty by default).

parseState(response, role) : void​

Parses a standard V2 response and sets the state properties to the state object on the instance. The response parameter is an object with a response object; either a complete response, or just the results sub-object, if it is present in the response as a wrapper. The role parameter is a string choosing the fields role, which the state should be received for; the default value is "properties".

See Also​

StateRequestorMixin. FieldsV2Mixin