HeaderAttribute

HeaderAttribute is used for decorating direct model header properties. It takes one argument, HeaderAttributeOptions, the type and the default values can be checked here.

Options

• useClass: boolean | class | () => class

  • optional
  • when omitted, the property value from the response will directly be used as a value of decorated model property
  • when true, an instance of property type class will be used as a value of decorated model property. While instantiating an instance of type class, the raw value of the property from the response will be passed as a first parameter to the constructor
  • when string, the class will be searched in DatastoreService.modelTypes based on modelType (see DefiningModelRelationships)
  • when function, the function will be called and it is expected of function to return a class which should be instantiated
  • when instance of SimpleHalModel or HalModel, the value of useClass property will be used as a class for instantiating the property value. While instantiating an instance of type class, the raw value of the property from the response will be passed as a first parameter to the constructor

• transformResponseValue: (rawAttribute: any) => any

  • optional
  • when provided, the raw property value from the response is passed to transformResponseValue function and returned value is saved to the model (instead of raw value from the response).

• transformBeforeSave: (rawAttribute: any) => any

  • when provided, the model property value is passed to the transformResponseValue function and returned value is used while creating a payload for the request

• externalName: string

  • if your model property name and the property name fetched from the server are different, you can specify the external property name setting this property
  • this name will be used when parsing a response from server and also when generating a payload for sending it to the server

Example

Raw response fetched from the server

GET /User/1

Headers:
Content-Type: text/html;
language: en;

{
  "id": "1",
  "name": "John",
  "additionalInfo": {
    "height": "170",
    "weight": "75"
  }
},
...

class User extends HalModel {
  @Attribute()
  public name: string;

  @HeaderAttribute()
  public language: Language;
}

After the model creation, user.language will be equal to en and when saving the model, language header will be set.