A CSV stream reader, with many many features, and ability to work with the largest datasets
npm install csv-reader.pause() if you need some time to process the row and .resume() when you are ready to receive and process more rows.
npm install --save csv-reader
`
The options you can pass are:
Name | Type | Default | Explanation
---- |-----------|---------| -----------
delimiter | String | , | The character that separates between cells
multiline | Boolean | true | Allow multiline cells, when the cell is wrapped with quotes ("...\n...")
allowQuotes | Boolean | true | Should quotes be treated as a special character that wraps cells etc.
skipEmptyLines | Boolean | false | Should empty lines be automatically skipped?
~~skipHeader~~ | Boolean | false | Should the first header row be skipped? (Deprecated, please use skipLines)
skipLines | Number | 0 | Number of lines to skip (if skipHeader is true, then this gets +1) (after the header line if headerLine is set)
headerLine | Number | 0 | Line number of the header (skipLines will be lines skipped after the header line)
asObject | Boolean | false | If true, each row will be converted automatically to an object based on the header. This adds 1 to skipLines.
parseNumbers | Boolean | false | Should numbers be automatically parsed? This will parse any format supported by parseFloat including scientific notation, Infinity and NaN.
parseBooleans | Boolean | false | Automatically parse booleans (strictly lowercase true and false)
ltrim | Boolean | false | Automatically left-trims columns
rtrim | Boolean | false | Automatically right-trims columns
trim | Boolean | false | If true, then both 'ltrim' and 'rtrim' are set to true
Events:
A 'data' event will be emitted with each row, either in an array format ((string|number|boolean)[]) or an Object format (Object), depending on the asObject option.
A preliminary 'header' event will be emitted with the first row, only in an array format, and without any interpolation to different types (string[]).
Of course other events as usual - end and error.
Usage example:
`javascript
const Fs = require('fs');
const CsvReadableStream = require('csv-reader');
let inputStream = Fs.createReadStream('my_data.csv', 'utf8');
inputStream
.pipe(new CsvReadableStream({ parseNumbers: true, parseBooleans: true, trim: true }))
.on('data', function (row) {
console.log('A row arrived: ', row);
})
.on('end', function () {
console.log('No more rows!');
});
`
A common issue with CSVs are that Microsoft Excel for some reason does not save UTF8 files. Microsoft never liked standards.
In order to automagically handle the possibility of such files with ANSI encodings arriving from user input, you can use the autodetect-decoder-stream like this:
`javascript
const Fs = require('fs');
const CsvReadableStream = require('csv-reader');
const AutoDetectDecoderStream = require('autodetect-decoder-stream');
let inputStream = Fs.createReadStream('my_data.csv')
.pipe(new AutoDetectDecoderStream({ defaultEncoding: '1255' })); // If failed to guess encoding, default to 1255
// The AutoDetectDecoderStream will know if the stream is UTF8, windows-1255, windows-1252 etc.
// It will pass a properly decoded data to the CsvReader.
inputStream
.pipe(new CsvReadableStream({ parseNumbers: true, parseBooleans: true, trim: true }))
.on('data', function (row) {
console.log('A row arrived: ', row);
}).on('end', function () {
console.log('No more rows!');
});
``