import 'reflect-metadata' import {collect, Collection} from "../../util"; import { DependencyKey, DependencyRequirement, DEPENDENCY_KEYS_METADATA_KEY, DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, isInstantiable, InjectionType, DEPENDENCY_KEYS_SERVICE_TYPE_KEY, PropertyDependency, } from "../types"; import {Container} from "../Container"; /** * Get a collection of dependency requirements for the given target object. * @param {Object} target * @return Collection */ function initDependencyMetadata(target: Object): Collection { const paramTypes = Reflect.getMetadata('design:paramtypes', target) return collect(paramTypes).map((type, idx) => { return { paramIndex: idx, key: type, overridden: false, } }) } /** * Class decorator that marks a class as injectable. When this is applied, dependency * metadata for the constructors params is resolved and stored in metadata. * @constructor */ export const Injectable = (): ClassDecorator => { return (target) => { const meta = initDependencyMetadata(target) const existing = Reflect.getMetadata(DEPENDENCY_KEYS_METADATA_KEY, target) const new_meta = new Collection() if ( existing ) { const max_new = meta.max('paramIndex') const max_existing = existing.max('paramIndex') for ( let i = 0; i <= Math.max(max_new, max_existing); i++ ) { const existing_dr = existing.firstWhere('paramIndex', '=', i) const new_dr = meta.firstWhere('paramIndex', '=', i) if ( existing_dr && !new_dr ) { new_meta.push(existing_dr) } else if ( new_dr && !existing_dr ) { new_meta.push(new_dr) } else if ( new_dr && existing_dr ) { if ( existing_dr.overridden ) { new_meta.push(existing_dr) } else { new_meta.push(new_dr) } } } } else { new_meta.concat(meta) } Reflect.defineMetadata(DEPENDENCY_KEYS_METADATA_KEY, new_meta, target) } } /** * Mark the given class property to be injected by the container. * If a `key` is specified, that DependencyKey will be injected. * Otherwise, the DependencyKey is inferred from the type annotation. * @param key * @constructor */ export const Inject = (key?: DependencyKey): PropertyDecorator => { return (target, property) => { let propertyMetadata = Reflect.getMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, target?.constructor || target) as Collection if ( !propertyMetadata ) { propertyMetadata = new Collection() Reflect.defineMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, propertyMetadata, target?.constructor || target) } const type = Reflect.getMetadata('design:type', target, property) if ( !key && type ) key = type if ( key ) { const existing = propertyMetadata.firstWhere('property', '=', property) if ( existing ) { existing.key = key } else { propertyMetadata.push({ property, key }) } } Reflect.defineMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, propertyMetadata, target?.constructor || target) } } /** * Parameter decorator to manually mark a parameter as being an injection target on injectable * classes. This can be used to override the dependency key of a given parameter. * @param {DependencyKey} key * @constructor */ export const InjectParam = (key: DependencyKey): ParameterDecorator => { return (target, property, paramIndex) => { if ( !Reflect.getMetadata(DEPENDENCY_KEYS_METADATA_KEY, target) ) { Reflect.defineMetadata(DEPENDENCY_KEYS_METADATA_KEY, initDependencyMetadata(target), target) } const meta = Reflect.getMetadata(DEPENDENCY_KEYS_METADATA_KEY, target) const req = meta.firstWhere('paramIndex', '=', paramIndex) if ( req ) { req.key = key req.overridden = true } else { meta.push({ paramIndex, key, overridden: true }) } Reflect.defineMetadata(DEPENDENCY_KEYS_METADATA_KEY, meta, target) } } /** * Class decorator that registers the class as a singleton instance in the global container. * @param {string} name */ export const Singleton = (name?: string): ClassDecorator => { return (target) => { if ( isInstantiable(target) ) { const injectionType: InjectionType = { type: name ? 'named' : 'singleton', ...(name ? { name } : {}) } Reflect.defineMetadata(DEPENDENCY_KEYS_SERVICE_TYPE_KEY, injectionType, target) Injectable()(target) if ( name ) { Container.getContainer().registerNamed(name, target) } else { Container.getContainer().register(target) } } } }