pip-services4-components-node/src/run/Opener.ts

Portable Component Model in Node.js / ES2017

/** @module run */

import { IContext } from "../context/IContext";

/**
 * Helper class that opens components.
 * 
 * [[IOpenable]]
 */
export class Opener {
    /**
     * Checks if specified component is opened.
     * 
     * To be checked components must implement [[IOpenable]] interface.
     * If they don't the call to this method returns true.
     * 
     * @param component     the component that is to be checked.
     * @returns true if component is opened and false otherwise.
     * 
     * @see [[IOpenable]]
     */
    public static isOpenOne(component: any): boolean {
        if (typeof component.isOpen === "function") {
            return component.isOpen();
        }
        return true;
    }    

    /**
     * Checks if all components are opened.
     * 
     * To be checked components must implement [[IOpenable]] interface.
     * If they don't the call to this method returns true.
     * 
     * @param components     a list of components that are to be checked.
     * @returns true if all components are opened and false if at least one component is closed.
     * 
     * @see [[isOpenOne]]
     * @see [[IOpenable]]
     */
    public static isOpen(components: any[]): boolean {
        if (components == null) return true;
        
        let result = true;
        for (const component of components) {
            result = result && Opener.isOpenOne(component);
        }
        
        return result;
    }

    /**
     * Opens specific component.
     * 
     * To be opened components must implement [[IOpenable]] interface.
     * If they don't the call to this method has no effect.
     * 
     * @param context     (optional) execution context to trace execution through call chain.
     * @param component         the component that is to be opened.
     * 
     * @see [[IOpenable]]
     */
    public static async openOne(context: IContext, component: any): Promise<void> {
        if (typeof component.open === "function") {
            await component.open(context);
        }
    }    

    /**
     * Opens multiple components.
     * 
     * To be opened components must implement [[IOpenable]] interface.
     * If they don't the call to this method has no effect.
     * 
     * @param context     (optional) execution context to trace execution through call chain.
     * @param components         the list of components that are to be closed.
     * 
     * @see [[openOne]]
     * @see [[IOpenable]]
     */
    public static async open(context: IContext, components: any[]): Promise<void> {
        for (const component of components) {
            await Opener.openOne(context, component);
        }
    }

}