baozhida-logistics-app/node_modules/barcode

barcode generator

Generate 1D and 2D barcodes

Supported 1D types

• Code39
• Codabar
• Code128
• UPC-A
• UPC-E
• EAN-13

Supported 2D types

• QR Code (comming soon)
• DataMatrix (comming soon)
• PDF417 (comming soon)

Requirements

• A working installation of GraphicsMagick.
• node >= 0.10.0

Installing

npm install barcode

Usage

Set it up and specify your type and options. The following 3 are the only required ones.

var barcode = require('barcode');
var code39 = barcode('code39', {
	data: "it works",
	width: 400,
	height: 100,
});

Next choose from the three methods below how you want to output your barcode.

Stream

Get a stream of the final image data. you can collect this and save out a new PNG (default type), pipe it elsewhere, or save it to a CDN.

code39.getStream(function (err, readStream) {
	if (err) throw err;

	// 'readStream' is an instance of ReadableStream
	readStream.pipe(CdnWriteStream);
});

File to disk

Save an image out to the file system, pretty simple. Just be sure to specify your outfile.

var outfile = path.join(__dirname, 'imgs', 'mycode.png')
code39.saveImage(outfile, function (err) {
	if (err) throw err;

	console.log('File has been written!');
});

Base64 encoded img src

Often times, barcodes are single use for a single print or whatever. With this method, we can create one on the fly and just send the base64 encoded image to the browser through the HTML.

code39.getBase64(function (err, imgsrc) {
	if (err) throw err;

	// if we're using HTTP or another framework
	res.end('<img src="' + imgsrc + '">');
});

Rewrite

Much of this will be due for a rewrite in the near future. 2.0 might make some API changes, but I will keep it as close to the original as possible.

Some goals for the rewrite:

• Externalize as much as possible
  • checksum calculations
  • error correcting calculations
• Abstract the drawing part
  • Allow for the 3 ways to accept the data currently implemented
  • Be able to print numbers below barcodes
• Break the process up into more defined and testable steps
  • Check for issues with settings
  • Calculate checksums (if applicable)
  • Create pattern in a data structure
  • Send the pattern to the drawer

I hope to eventually make it more maintainable this way instead of the endless amounts of spaghetti code.

License

The MIT License (MIT)