Example of a simple functional file

sample.js

'use strict';


/**
 * This notation was generated by templates.
 * // -------------------------------------------------
 * GLOBAL FILE NOTATIONS
 * Project of: Rocketdesk Auth
 * Filename: Connector.js by jimmie
 * Created: 2017-07-17 @ 23:00
 * Product of: Rocketdesk.net
 * // -------------------------------------------------
 * Make sure this file is part of its proper namespace
 * and project before moving on.
 * // -------------------------------------------------
 * Code-tags conventionally should be used (See below) :
 * TODO - Something that someone need to do.
 * DOING - Self remind for what you are doing.
 * CONSIDER - Reminder to consider a change or addition.
 * BUG - The below section of a code cause a bug.
 * FIXME - The below section of code need to be fixed.
 * HACK - The below section of code is a workaround.
 * XXX - Any notation important enough to consider implementing.
 * CLARIFY - Very incomprehensible section of code below.
 *
 * Created by jimmie on (2017-07-17).
 *
 * Repository link: https://github.com/jimmiehansson/rocket.git
 */


/**
 * Require node specific modules and libraries
 * here to separate from the rest of the code.
 */
const { Pool, Client } = require('pg');


/**
 * Import universal/associated libraries
 * here to separate from the rest of the code.
 */
import {
    scheduleConnection,
    eventDispatch,
} from './PoolHandler';
import {
    PRE_ENV
} from './Constants/Environment';
import {
    populate
} from './Config/Db';
import {
    PGSQL_POOL_CONNECTION_TIMEOUT_MILLIS,
    PGSQL_POOL_IDLE_TIMEOUT_MILLIS,
    PGSQL_POOL_MIN_CLIENTS,
    PGSQL_POOL_MAX_CLIENTS,
    PGSQL_POOL_EVENT_CONNECT,
    PGSQL_POOL_EVENT_ACQUIRE,
    PGSQL_POOL_EVENT_ERROR,
    PGSQL_POOL_SSL,
    PGSQL_CLIENT_SSL,
    PGSQL_CLIENT_TYPES
} from './Constants/Common';
import {

} from './Constants/Language/English';


/**
 * DOING: Get the environment
 * before initiating the connections.
 * Production should be set explicitly.
 * @param PRE_ENV
 */
const loadEnvironment = PRE_ENV||'local';


/**
 * DOING: Should create a connection instance
 * with the populate config object and return
 * a pool reference.
 * @param {string} configurationType
 * @returns {PG.Pool}
 */
const initPoolConnector = configurationType => new Pool(
    populate.default()[configurationType],
    {
        connectionTimeoutMillis : PGSQL_POOL_CONNECTION_TIMEOUT_MILLIS,
        idleTimeoutMillis : PGSQL_POOL_IDLE_TIMEOUT_MILLIS,
        min : PGSQL_POOL_MIN_CLIENTS,
        max : PGSQL_POOL_MAX_CLIENTS,
        ssl : PGSQL_POOL_SSL
    });


/**
 * DOING: Should create a connection instance
 * with the populate config object and return
 * a client reference.
 * @param {string} configurationType
 * @returns {PG.Client}
 */
const initClientConnector = configurationType => new Client(
    populate.default()[configurationType],
    {
        ssl : PGSQL_CLIENT_SSL,
        types : PGSQL_CLIENT_TYPES
    });


/**
 * DOING: Should register the events
 * from the connection being registered.
 * @param db
 */
export const registerConnection = db => {
    db
        .on(PGSQL_POOL_EVENT_CONNECT, client => registerClient(db, client))
        .on(PGSQL_POOL_EVENT_ACQUIRE, client => registerAcquire(db, client))
        .on(PGSQL_POOL_EVENT_ERROR, error => registerError(db, error));
};


/**
 * DOING: Should delegate the connection
 * event from the pool handler.
 * @param db
 * @param client
 */
const registerClient = (db, client) => eventDispatch(PGSQL_POOL_EVENT_CONNECT, db, client);


/**
 * DOING: Should delegate the acquire
 * event from the pool handler.
 * @param db
 * @param client
 */
const registerAcquire = (db, client) => eventDispatch(PGSQL_POOL_EVENT_ACQUIRE, db, client);


/**
 * DOING: Should delegate the error
 * event from the pool handler.
 * @param db
 * @param client
 */
const registerError = (db, client) => eventDispatch(PGSQL_POOL_EVENT_ERROR, db, client);


/**
 * DOING: Should return a reference object
 * to the client cursor with the current environment.
 * @param {boolean} instanceType
 * @returns {Object}
 */
export const dbConnector = instanceType => (instanceType) ? scheduleConnection(initPoolConnector(loadEnvironment)) : scheduleConnection(initClientConnector(loadEnvironment));