gistfile1.js

/**
 * Parse Employee Data in CSV
 * CAUTION : Do not attempt to understand this code!!!
**/


var csv = require('fast-csv')
  , fs	= require('fs')
  , Q	= require('q');

// get entity classes;
var ObjectID     = require( 'mongoose' ).Types.ObjectId
  , Company      = require( '../entities/company' )
  , Employee     = require( '../entities/employee' )
  , Salary       = require( '../entities/salary' )
  , Group        = require( '../entities/group' )
  , events		 = require( 'events' );


/**
 * EmployeeParser will emit the following events
 * 'error' -> when an exception is caught
 * 'partial' -> upon failure to create all employees
 * 'completed' -> upon successfull creation of all employees
 **/
var EmployeeParser = function(){
	// call event emitter constructor on EmployeeParser instance
	events.EventEmitter.call( this );

	// provision needed persistent data structures
	this.__empList  = [];
	this.__failList = [];
}
// make EmployeeParser inherit from EventEmitter
require( 'util' ).inherits( EmployeeParser, events.EventEmitter );


EmployeeParser.prototype.createEmployees = function( csvFile ) {
	// preserve object ref
	var _this = this;

	csv
		.fromPath ( csvFile, { headers: true, ignoreEmpty: true, trim: true })
		.validate ( _this.protocols.isValid )
		.transform( _this.protocols.transform )

		.on( 'data-invalid', _this.protocols.crash  )
		.on( 'record', 		 _this.protocols.addEmp )
		.on( 'end', 		 _this.protocols.finish );

};

EmployeeParser.prototype.instance = {
	sam : [],
	ako : []
};

EmployeeParser.prototype.protocols = {

	crash  : function( invalidEmp ){
		// employee data is invalid
		// add row number to failList array
		console.log( 'crash protocol initiated' );
		this.ako.push( invalidEmp );
	},
	addEmp : function( empObj ){
		// push emp into employee array
		console.log( 'addEmp protocol initiated' );
		console.log( 'this : ', this, ' - __empList : ', this.sam );
		this.sam.push( empObj );
	},
	finish : function(){
		// parsing completed
		// emit 'completed' or 'partial'
		// depending on whether failList is empty or not
		console.log( 'finish protocol initiated' );
		this.emit( 'completed', this.sam );
	},
	isValid : function( empData ){
		// check if employee data is valid
		// by testing for all required fields
		console.log( 'isValid protocol initiated' );
		var dataIsValid = true;

		if( empData )
			return dataIsValid;
	},
	transform : function( empData ){
		// create employee object here
		console.log( 'transform protocol initiated' );
		return empData;
	}

};

module.exports = EmployeeParser;