API Reference ​

class Data ​

Base class for domain models. Should be extended with a set of class fields that describe the shape of desired model.

Example ​

import { Data } from "dataclass";

class Project extends Data {
  id: string = "";
  name: string = "Untitled Project";
  createdBy: string = "";
  createdAt: Date | null = null;
}

static create(values) ​

Once extended, data class can be instantiated with a new data. That's the way to get a unique immutable persistent model.

Arguments ​

1. values (Object): POJO which shape satisfy the contract described during class extension. If you use Flow, it will warn you about the mistakes.

Returns ​

(Data): an instance of your data class with all the defined fields accessible as in the plain object. Properties are read only.

Example ​

class Vehicle extends Data {
  model: string = "Unspecified";
  manufacturer: string = "Unknown";
}

let vehicle = Vehicle.create({ manufacturer: "Tesla", model: "S" });
// > Vehicle { manufacturer: 'Tesla', model: 'S' }

vehicle.manufacturer;
// > 'Tesla'

method copy(values) ​

Create new immutable instance based on an existent one. Since properties are read only, that's the way to provide an updated model's fields to a consumer keeping the rest unchanged.

Arguments ​

1. values (Data): POJO that includes new values that you want to change. Properties should satisfy the contract described by the class.

Returns ​

(Data): new instance of the same type and with new values.

Example ​

class User extends Data {
  name: string = "Anonymous";
  email: string | null = null;
}

let user = User.create({ name: "Liza" });
// > User { name: 'Liza', email: null }

let updated = user.copy({ email: "liza@example.com" });
// > User { name: 'Liza', email: 'liza@example.com' }

method equals(other) ​

Since immutable instances always have not equal references, there should be a way to compare the actual values.

Arguments ​

1. other (Object): a data object of the same class as a target one.

Returns ​

(Boolean): false if some field value is not strictly equal in both instances. true otherwise.

Example ​

class Box extends Data {
  size: number = 16;
  color: string = "red";
}

let first = Box.create({ color: "green" });
let second = Box.create({ color: "blue" });
let third = first.copy({ color: "blue" });

first === second;
// > false

first === third;
// > false

first.equals(second);
// > false

second.equals(third);
// > true