Value

@tsed/di

Usage

import { Value } from "@tsed/di";

See /packages/di/src/common/decorators/value.ts.

Overview

function Value(expression: string, defaultValue?: unknown): PropertyDecorator;

• expression (string): Dot-notation path to the configuration value

• defaultValue (unknown): Optional. default value if not found

Description

Inject a reactive configuration value into a property.

Creates a getter/setter that always reflects the current configuration value. Unlike @Constant(), the value is not frozen and can change at runtime.

Usage

import {Injectable, Value} from "@tsed/di";

@Injectable()
export class MyService {
  @Value("swagger.path")
  swaggerPath: string;

  @Value("api.port", 3000)
  port: number;

  constructor() {
    // Not available yet - undefined
  }

  $onInit() {
    console.log(this.swaggerPath); // Current value
    this.swaggerPath = "/new-path"; // Can be modified
  }
}

Difference from @Constant

• @Constant: Frozen immutable value (deep clone)
• @Value: Reactive value (always reads current config)