pip-services3-commons-node/src/run/Cleaner.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 cleans stored object state.
 * 
 * @see [[ICleanable]]
 */
export class Cleaner {
	/**
	 * Clears state of specific component.
	 * 
	 * To be cleaned state components must implement [[ICleanable]] 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 cleaned.
     * @param callback 			callback function that returns error or null no errors occured.
	 * 
	 * @see [[ICleanable]]
	 */
	public static clearOne(correlationId: string, component: any, callback?: (err: any) => void): void {
        if (_.isFunction(component.clear)) {
			try {
				component.clear(correlationId);
			} catch (err) {
				if (callback) callback(err);
				else throw err;
			}
		} else if (callback)
			callback(null);
	}

	/**
	 * Clears state of multiple components.
	 * 
	 * To be cleaned state components must implement [[ICleanable]] 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 cleaned.
     * @param callback 			callback function that returns error or null no errors occured.
	 * 
	 * @see [[clearOne]]
	 * @see [[ICleanable]]
	 */
	public static clear(correlationId: string, components: any[], callback?: (err: any) => void) {		
        async.eachSeries(
            components, 
            (component, callback) => {
				Cleaner.clearOne(correlationId, component, callback);
            },
            (err) => {
				if (callback) callback(err);
				else if (err) throw err;
			}
        );            
	}
}