pip-services3-components-nodex/obj/src/build/CompositeFactory.js

Component definitions for Pip.Services in Node.js / ES2017

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.CompositeFactory = void 0;
const CreateException_1 = require("./CreateException");
/**
 * Aggregates multiple factories into a single factory component.
 * When a new component is requested, it iterates through
 * factories to locate the one able to create the requested component.
 *
 * This component is used to conveniently keep all supported factories in a single place.
 *
 * ### Example ###
 *
 *     let factory = new CompositeFactory();
 *     factory.add(new DefaultLoggerFactory());
 *     factory.add(new DefaultCountersFactory());
 *
 *     let loggerLocator = new Descriptor("*", "logger", "*", "*", "1.0");
 *     factory.canCreate(loggerLocator); 		// Result: Descriptor("pip-service", "logger", "null", "default", "1.0")
 *     factory.create(loggerLocator); 			// Result: created NullLogger
 */
class CompositeFactory {
    /**
     * Creates a new instance of the factory.
     *
     * @param factories 	a list of factories to embed into this factory.
     */
    constructor(...factories) {
        this._factories = [];
        if (factories != null) {
            this._factories = this._factories.concat(factories);
        }
    }
    /**
     * Adds a factory into the list of embedded factories.
     *
     * @param factory 	a factory to be added.
     */
    add(factory) {
        if (factory == null) {
            throw new Error("Factory cannot be null");
        }
        this._factories.push(factory);
    }
    /**
     * Removes a factory from the list of embedded factories.
     *
     * @param factory 	the factory to remove.
     */
    remove(factory) {
        this._factories = this._factories.filter((f) => f != factory);
    }
    /**
     * Checks if this factory is able to create component by given locator.
     *
     * This method searches for all registered components and returns
     * a locator for component it is able to create that matches the given locator.
     * If the factory is not able to create a requested component is returns null.
     *
     * @param locator 	a locator to identify component to be created.
     * @returns			a locator for a component that the factory is able to create.
     */
    canCreate(locator) {
        if (locator == null) {
            throw new Error("Locator cannot be null");
        }
        // Iterate from the latest factories
        for (let index = this._factories.length - 1; index >= 0; index--) {
            let thisLocator = this._factories[index].canCreate(locator);
            if (thisLocator != null) {
                return thisLocator;
            }
        }
        return null;
    }
    /**
     * Creates a component identified by given locator.
     *
     * @param locator 	a locator to identify component to be created.
     * @returns the created component.
     *
     * @throws a CreateException if the factory is not able to create the component.
     */
    create(locator) {
        if (locator == null) {
            throw new Error("Locator cannot be null");
        }
        // Iterate from the latest factories
        for (let index = this._factories.length - 1; index >= 0; index--) {
            let factory = this._factories[index];
            if (factory.canCreate(locator) != null) {
                return factory.create(locator);
            }
        }
        throw new CreateException_1.CreateException(null, locator);
    }
}
exports.CompositeFactory = CompositeFactory;
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