A typescript library to deserialize json into typescript classes and serialize classes into json.
npm install typescript-json-serializer --save
# or
yarn add typescript-json-serializerYou also need to set experimentalDecorators and emitDecoratorMetadata to true into the tsconfig.json file.
For example:
{
"compilerOptions": {
...
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
...
}
}There are two decorators and two functions that you can import inside a typescript file.
import { JsonProperty, Serializable, deserialize, serialize } from 'typescript-json-serializer';// Serializable decorator set a class as serializable.
// It can take options as parameter:
// - formatPropertyNames function to format the property names
// provided by the json you want to serialize to match
// with your class property names
//
// BREAKING CHANGE: Since version 2.0.0 the
// parameter `baseClassName` is not needed anymore
type FormatPropertyNameProto = (propertyName: string) => string;
type SerializableOptions = {
formatPropertyNames: FormatPropertyNameProto
}
@Serializable(options?: SerializableOptions)// JsonProperty decorator set metadata to the property.
// It can take some optional parameters like:
// - the name of json property if diverge from the class property
// (this value override the `formatPropertyNames` option from
// `Serializable` decorator)
// - the type of the property (if needed)
// - a predicate function that return a type (if needed)
// - a function to transform data on deserialize
// - a function to transform data on serialize
// - the names of properties to merge (the `formatPropertyNames`
// from `Serializable` decorator is ignored)
// - a boolean to tell that the property is a dictionary
type IOProto = (property: any, currentInstance: any) => {};
type PredicateProto = (property: any) => {};
@JsonProperty(args?:
| string
| {
name?: string,
type?: Function,
onDeserialize?: IOProto,
onSerialize?: IOProto,
postDeserialize?: IOProto,
isDictionary?: boolean
}
| {
name?: string,
predicate?: PredicateProto,
onDeserialize?: IOProto,
onSerialize?: IOProto,
postDeserialize?: IOProto,
isDictionary?: boolean
}
| {
names?: Array<string>,
type?: Function,
onDeserialize?: IOProto,
onSerialize?: IOProto,
postDeserialize?: IOProto
}
| {
names?: Array<string>,
predicate?: PredicateProto,
onDeserialize?: IOProto,
onSerialize?: IOProto,
postDeserialize?: IOProto
})// serialize function transform typescript class into json.
// It takes two parameters:
// - a instance of the class to serialize
// - a boolean to remove undefined property (default true)
serialize(instance: any, removeUndefined: boolean = true): any// deserialize function transform json into typescript class.
// It takes two parameters:
// - json data
// - the class you want to deserialize into
deserialize<T>(json: any, type: new (...params) => T): T// Import decorators from library
import { Serializable, JsonProperty } from 'typescript-json-serializer';
// Enums
export enum Gender {
Female,
Male,
Other
}
export enum Status {
Alive = 'Alive',
Sick = 'Sick',
DeadAndAlive = 'Dead and alive',
Dead = 'Dead'
}
// Create a serializable class: LivingBeing
// Serializable decorator
@Serializable()
export class LivingBeing {
/** The living being id (PK) */
@JsonProperty() id: number;
}
// Create a serializable class that extends LivingBeing: Human
@Serializable()
export class Human extends LivingBeing {
constructor(
// This comment works
@JsonProperty() public name: string,
public id: number,
@JsonProperty() public gender: Gender,
/** This comment works */
@JsonProperty() public readonly birthDate: Date
) {
super();
this.id = id;
}
}
// Create a serializable class: PhoneNumber
@Serializable()
export class PhoneNumber {
@JsonProperty() countryCode: string;
@JsonProperty() value: string;
}
// Create a serializable class that extends Human: Employee
@Serializable()
export class Employee extends Human {
/** The employee's email */
@JsonProperty() email: string;
/** Predicate function to determine if the property type is PhoneNumber or a primitive type */
@JsonProperty({
predicate: property => {
if (property && property.value !== undefined) {
return PhoneNumber;
}
}
})
phoneNumber: PhoneNumber | string;
constructor(
public name: string,
public id: number,
public gender: Gender,
public birthDate: Date
) {
super(name, id, gender, birthDate);
}
}
// Create a serializable class: Animal
@Serializable()
export class Animal {
@JsonProperty() id: number;
@JsonProperty() name: string;
@JsonProperty() birthDate: Date;
@JsonProperty() numberOfPaws: number;
@JsonProperty() gender: Gender;
// Enum value (string)
@JsonProperty() status: Status;
// Specify the property name of json property if needed
@JsonProperty('childrenIdentifiers')
childrenIds: Array<number>;
constructor(name: string) {
this.name = name;
}
}
// Create a serializable class that extends Animal (which extends LivingBeing): Panther
@Serializable()
export class Panther extends Animal {
@JsonProperty() color: string;
// JsonProperty directly inside the constructor
// for property parameters
public constructor(
name: string,
@JsonProperty() public isSpeckled: boolean
) {
super(name);
}
}
// Create a serializable class that extends Animal (which extends LivingBeing): Snake
@Serializable()
export class Snake extends Animal {
@JsonProperty() isPoisonous: boolean;
public constructor(name: string) {
super(name);
}
}
// Create a serializable empty class that extends Animal (which extends LivingBeing): UnknownAnimal
@Serializable()
export class UnknownAnimal extends Animal {
public constructor(name: string) {
super(name);
}
}
// Create a serializable class: Zoo
// Function to transform coordinates into an array
const coordinatesToArray = (coordinates: { x: number; y: number; z: number }): Array<number> => {
return Object.values(coordinates);
};
// Function to transform an array into coordinates
const arrayToCoordinates = (array: Array<number>): { x: number; y: number; z: number } => {
return {
x: array[0],
y: array[1],
z: array[2]
};
};
// A predicate function use to determine what is the
// right type of the data (Snake or Panther)
const snakeOrPanther = animal => {
return animal && animal['isPoisonous'] !== undefined ? Snake : Panther;
};
@Serializable()
export class Zoo {
// Here you do not need to specify the type
// inside the decorator
@JsonProperty() boss: Employee;
@JsonProperty() city: string;
@JsonProperty() country: string;
// Property with transform functions executed respectively
// on serialize and on deserialize
@JsonProperty({ onDeserialize: arrayToCoordinates, onSerialize: coordinatesToArray })
coordinates: { x: number; y: number; z: number };
// Array of none-basic type elements
@JsonProperty({ type: Employee })
employees: Array<Employee>;
@JsonProperty() id: number;
@JsonProperty() name: string;
// Array of none-basic type elements where you need to
// specify the name of the json property
// and use the predicate function to cast the deserialized
// object into the correct child class
@JsonProperty({ name: 'Animals', predicate: snakeOrPanther })
animals: Array<Animal>;
// Property that can be Panther or Snake type
// Use again the predicate function
@JsonProperty({ predicate: snakeOrPanther })
mascot: Panther | Snake;
// Array of empty child classes
@JsonProperty({ type: UnknownAnimal })
unknownAnimals: Array<UnknownAnimal>;
@JsonProperty() bestEmployeeOfTheMonth: Employee;
// Dictionary of PhoneNumber
@JsonProperty({ type: PhoneNumber, isDictionary: true })
phoneBook: {[id: string]: PhoneNumber};
// Property which will be not serialized and deserialized
// but event accessible and editable from Zoo class.
public isFree: boolean = true;
public constructor() { }
}
// Create a serializable class that extends Society: Organization
const prefixWithUnderscore = (propertyName: string) => `_${propertyName}`
// Instead of defining the JsonProperty name for each property
// just use a function to do it for all of them.
// Warning: The properties of the base class will be formatted as well
@Serializable({ formatPropertyNames: prefixWithUnderscore })
export class Organization extends Society {
// Override `formatPropertyNames`
@JsonProperty({ name: 'zoos', type: Zoo }) zoos: Array<Zoo>;
// To merge multiple properties in a single one
// use the property `names`.
// If you don't create your own merge with the `onDeserialize`
// and `onSerialize` function, it will just merge properties in this
// one when using `deserialize` and split back
// when using `serialize`
@JsonProperty({
names: ['_mainShareholder', '_secondaryShareholder', '_thirdShareholder'],
type: Human,
onDeserialize: value => Object.values(value),
onSerialize: value => {
return {
_mainShareholder: value[0],
_secondaryShareholder: value[1],
_thirdShareholder: value[2]
};
}
})
shareholders: Array<Human>;
}
// Create a serializable class: Society
@Serializable()
export class Organization {
@JsonProperty() id: string;
@JsonProperty() name: string;
}// data.ts
export const data: any = {
_id: '1',
_name: 'Zoos Organization',
zoos: [
{
id: 15,
name: 'The Greatest Zoo',
city: 'Bordeaux',
coordinates: [1, 2, 3],
country: 'France',
boss: {
id: 1,
name: 'Bob Razowsky',
birthDate: '1984-04-03T22:00:00.000Z',
email: 'bob.razowsky@tgzoo.fr',
gender: 1
},
employees: [
{
id: 1,
name: 'Bob Razowsky',
birthDate: '1984-04-03T22:00:00.000Z',
email: 'bob.razowsky@tgzoo.fr',
gender: 1
},
{
id: 2,
name: 'Mikasa Ackerman',
birthDate: '1984-01-11T22:00:00.000Z',
email: 'mikasa.ackerman@tgzoo.fr',
gender: 0
},
{
id: 3,
name: 'Red Redington',
birthDate: '1970-12-04T22:00:00.000Z',
email: 'red.redington@tgzoo.fr',
gender: 1
},
{
id: 4,
name: 'Fried Richter',
birthDate: '1994-04-01T22:00:00.000Z',
email: 'fried.richter@tgzoo.fr',
gender: 1
}
],
Animals: [
{
id: 1,
name: 'Bagheera',
birthDate: '2010-01-11T22:00:00.000Z',
numberOfPaws: 4,
gender: 1,
childrenIdentifiers: [2, 3],
color: 'black',
isSpeckled: false,
status: 'Sick'
},
{
id: 2,
name: 'Jolene',
birthDate: '2017-03-10T22:00:00.000Z',
numberOfPaws: 4,
gender: 0,
color: 'blond',
isSpeckled: true,
status: 'Alive'
},
{
id: 3,
name: 'Ka',
birthDate: '2018-09-09T00:00:00.000Z',
numberOfPaws: 0,
gender: 1,
isPoisonous: true,
status: 'Alive'
},
{
id: 4,
name: 'Schrodinger',
numberOfPaws: 4,
gender: 1,
color: 'brown',
isSpeckled: false,
status: 'Dead and alive'
}
],
mascot: {
id: 1,
name: 'Bagheera',
birthDate: '2010-01-11T22:00:00.000Z',
numberOfPaws: 4,
gender: 1,
childrenIdentifiers: [2, 3],
color: 'black',
isSpeckled: false,
status: 'Sick'
},
unknownAnimals: [
{
name: null
}
],
phoneBook: {
'1': {
value: '111-111-1111'
},
'2': {
value: '222-222-2222'
},
'3': {
value: '333-333-3333'
}
}
},
{
id: 16,
name: 'Zoo Zoo',
city: 'Paris',
coordinates: [4, 2, 3],
country: 'France',
boss: {
id: 2,
name: 'Sully',
birthDate: '1984-08-03T22:00:00.000Z',
email: 'sully.razowsky@tgzoo.fr',
gender: 1
},
employees: [],
Animals: [],
mascot: null,
unknownAnimals: []
}
],
_mainShareholder: {
id: 100,
name: 'Elon Musk',
birthDate: '1971-06-28T22:00:00.000Z',
gender: 1
},
_secondaryShareholder: null,
};// Import functions from library
import { deserialize, serialize } from 'typescript-json-serializer';
import { json } from '../json/data';
import { Organization } from '../models/organization';
// deserialize
const organization = deserialize<Organization>(json, Organization);
// serialize
const data = serialize(organization);
// or
const data = serialize(organization, false);npm run test
# or
yarn testGillian Pérard - @GillianPerard
- Hyeonsoo David Lee - @civilizeddev