pip-services3-commons-node/src/run/Opener.ts

Portable abstractions and patterns for Pip.Services in Node.js

/** @module run */
/** @hidden */ 
let _ = require('lodash');
/** @hidden */ 
let async = require('async');

/**
 * 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 (_.isFunction(component.isOpen))
			return component.isOpen();
		else
			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: boolean = true;
		for (let index = 0; index < components.length; index++)
			result = result && Opener.isOpenOne(components[index]);
		
		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 correlationId 	(optional) transaction id to trace execution through call chain.
	 * @param component 		the component that is to be opened.
     * @param callback 			callback function that returns error or null no errors occured.
	 * 
	 * @see [[IOpenable]]
	 */
	public static openOne(correlationId: string, component: any, callback?: (err: any) => void): void {
        if (_.isFunction(component.open)) {
			try {
				component.open(correlationId, callback);
			} catch (err) {
				if (callback) callback(err);
				else if (err) throw err;
			}
		} else if (callback)
			callback(null);
	}	

	/**
	 * Opens multiple components.
	 * 
	 * To be opened components must implement [[IOpenable]] interface.
	 * If they don't the call to this method has no effect.
	 * 
	 * @param correlationId 	(optional) transaction id to trace execution through call chain.
	 * @param components 		the list of components that are to be closed.
     * @param callback 			callback function that returns error or null no errors occured.
	 * 
	 * @see [[openOne]]
	 * @see [[IOpenable]]
	 */
	public static open(correlationId: string, components: any[], callback?: (err: any) => void): void {
        async.eachSeries(
            components,
            (component, callback) => {
                Opener.openOne(correlationId, component, callback);
            }, 
            (err) => {
				if (callback) callback(err);
				else if (err) throw err;
			}
        );
	}

}