#DelimitedFileReader

A promise enabled, ES6 Class for reading delimited text files and emitting the records as objects.

##Synopsis

Read the given file, listen to the various events to get the data:

const DelimitedFileReader = require('delimited-file-reader');

let fileReader = new DelimitedFileReader(',');

fileReader.on('comment', (comment) => {
    console.log(`comment: ${comment}`);
});

fileReader.on('data', (data) => {
    console.log(`data: ${JSON.stringify(data)}`);
});

fileReader.on('close', () => {
    console.log('Elvis has left the building!');
});

// The parse method takes a string filename or a read stream as an argument.
fileReader.parse('./simple-example.csv');


// comment: # Example file using comma delimited format with comments
// data: {"field_0":"value1-1","field_1":"value2-2"}
// data: {"field_0":"value2-1","field_1":"value2-2"}
// Elvis has left the building!

This code comes from the provided example file: simple-example.js

##Description

This class is a simple implementation of a delimited text file reader. The following are configurable.

In simpler terms:

• I have a delimited text file or stream with lf or lf\cr as record delimiters.
• The column delimiter can be expressed as a string or regular expresssion.
• They're may be comments in the file using a defined string in the starting position.
• I want to read the file and process each record as an object.
• I may want to name the properties of each object or I may let the class name them.

##Project Features

• ES6 Class
• Promise enabled
• Complete test coverage with Mocha and Chai
• JSDoc generated API documentation
• Rest parameters are used for maximum flexibility.

##Installation npm install delimited-file-reader --save

Git Repository: https://github.com/wildbillh/delimited-file-reader

##Documentation

There is JSDOC documentation provided: DelimitedFileReader.html

##Methods

###Constructor

constructor(delimiter = /[,]/, fields = [], commentChar = '#')

The constructor takes three defaulted parameters:

1. delimiter - defaults to a common. Can be any valid string or regular expresssion.
2. fields - defaults to an empty array. In this case, the class will generated field names. The user can also supply an array of strings.
3. commentChar - The string to use to designate a comment line (if it occurs at position 0). Set this to null of the feature should be disabled.

###parse

parse(filename)

This method starts the process of reading the files and emitting events. Prior to calling this method, the desired event listeners should be instantiated.

##Events

• close - File reading is complete and all records have been emitted.
• comment - A comment was encountered. The entire line is returned.
• data - Contains an object representing the record.
• error - Contains the error message.
• invalid - A record was encountered with the wrong number of fields. This can only occur if the user specifies field names. The entire line is returned.

Author: Bill Hodges