Serialization

The Fundamentals frontend package provides a comprehensive serialization system that enables type-safe JSON serialization and deserialization in TypeScript. This system maintains object identity, method access, and polymorphic type handling throughout the serialization process.

Overview

The serialization system consists of two main components that work together to provide full-featured object serialization:

• Field Decorator System: Provides runtime type metadata for proper deserialization
• DerivedTypes System: Enables polymorphic serialization with type identifiers

Key Features

• True Runtime Types: Deserialized objects are actual class instances, not plain JavaScript objects
• Method Preservation: Full access to class methods and business logic on deserialized instances
• Polymorphic Support: Automatic resolution of derived types based on type identifiers
• Type-Safe Collections: Proper typing for arrays and complex nested objects
• Deep Object Graphs: Maintaining correct types throughout complex object hierarchies
• Backend Integration: Seamless compatibility with .NET DerivedTypes system

Topics

Topic	Description
JsonSerializer	The core utility for type-safe JSON serialization and deserialization with runtime type preservation and method access.
Field Decorator	The @field decorator for runtime type information and proper object deserialization with full type safety.
DerivedTypes	Polymorphic serialization system that works with backend .NET implementation for type-safe object resolution.

Quick Start

Basic Field Declaration

import { field } from '@cratis/fundamentals';

export class User {
    @field(String)
    name!: string;
    
    @field(Number)
    age!: number;
    
    @field(Date)
    createdAt!: Date;
    
    // Methods are preserved after deserialization
    getDisplayName(): string {
        return `${this.name} (${this.age})`;
    }
}

Polymorphic Types

import { derivedType, field } from '@cratis/fundamentals';

@derivedType('550e8400-e29b-41d4-a716-446655440001')
export class CreditCard implements IPaymentMethod {
    @field(Number)
    amount!: number;
    
    @field(String)
    cardNumber!: string;
}

@derivedType('550e8400-e29b-41d4-a716-446655440002')
export class PayPal implements IPaymentMethod {
    @field(Number)
    amount!: number;
    
    @field(String)
    email!: string;
}

For detailed usage examples and advanced scenarios, see the individual topic documentation linked above.