reactant-di/dist/esm/decorators/lazy.js

A dependency injection lib for Reactant

import 'reflect-metadata';
import { METADATA_KEY } from '../constants.js';

/**
 * ## Description
 *
 * You can get a decorator `@lazy(serviceIdentifier)` with `getLazyDecorator((serviceIdentifier) => container.get(serviceIdentifier))`,
 * and use it on any one dependency property that you need to lazily get.
 *
 * ## Example
 *
 * ```ts
 * let container: Container;
 * const lazy = getLazyDecorator((serviceIdentifier) =>
 *   container.get(serviceIdentifier)
 * );
 *
 * @injectable()
 * class Foo {
 *   public get test() {
 *     return 'test';
 *   }
 * }
 *
 * @injectable()
 * class Bar {
 *   @lazy('foo')
 *   foo?: Foo;
 * }
 *
 * container = createContainer({
 *   ServiceIdentifiers: new Map(),
 * });
 *
 * const bar = container.get(Bar);
 *
 * container.bind('foo').to(Foo);
 * expect(bar.foo?.test).toBe('test');
 * ```
 */
var getLazyDecorator = function (getService) {
    return function (serviceIdentifier, enableCache) {
        if (enableCache === void 0) { enableCache = true; }
        return function (target, key) {
            function getter() {
                if (enableCache && !Reflect.hasMetadata(METADATA_KEY.lazy, this, key)) {
                    var service = getService(serviceIdentifier, this);
                    if (service !== null) {
                        Reflect.defineMetadata(METADATA_KEY.lazy, service, this, key);
                    }
                }
                if (Reflect.hasMetadata(METADATA_KEY.lazy, this, key)) {
                    return Reflect.getMetadata(METADATA_KEY.lazy, this, key);
                }
                return getService(serviceIdentifier, this);
            }
            function setter(newVal) {
                if (enableCache) {
                    Reflect.defineMetadata(METADATA_KEY.lazy, newVal, this, key);
                }
                else {
                    console.warn("\n          Disable cache and the property ".concat(key.toString(), " in class \"").concat(this.constructor.name, "\" instance failed to set value.\n        "));
                }
            }
            // It should be compatible with the TS decorator and the babel decorator
            return {
                configurable: true,
                enumerable: true,
                get: getter,
                set: setter,
            };
        };
    };
};

export { getLazyDecorator };