Methods Reference

bwipjs.request()

Usage

bwipjs.request(req, res [, overrides])

Returns a PNG image from the query args of a node.js http request object.

This function is asynchronous.

Node.js usage only.

bwipjs.toBuffer()

Usage

bwipjs.toBuffer(options[, callback])

Uses the built-in graphics drawing and zlib PNG encoding to return a barcode image in a node.js Buffer.

options are a bwip-js/BWIPP options object. callback is an optional callback handler with prototype:

function callback(err, png)

• err is an Error object or string. If err is set, png is null.
• png is a node Buffer containing the PNG image.

If callback is not provided, a Promise is returned.

Node.js usage only.

bwipjs.toCanvas()

Usage:

bwipjs.toCanvas(canvas, options)
bwipjs.toCanvas(options, canvas)

Uses the built-in graphics drawing. Identical to node.js toBuffer() rendering.

• canvas can be an HTMLCanvasElement or an ID string or unique selector string.
• options are a bwip-js/BWIPP options object.

This function is synchronous and throws on error.

Browser usage only.

bwipjs.fixupOptions()

Usage

bwipjs.fixupOptions(options)

Call this before passing your options object to a drawing constructor. For example:

// Draw the bar code with an SVG drawing object.
try {
	// fixupOptions() modifies options values (currently padding and
	// background color) to provide a simplified interface for the
	// drawing code.
	bwipjs.fixupOptions(opts);

	// The drawing needs FontLib
	var drawing = DrawingSVG(opts, bwipjs.FontLib);
	bwipjs.render(opts, drawing);
} catch (e) {
}

bwipjs.render()

Usage

bwipjs.render(options, drawing)

Renders a barcode using the provided drawing object.

This function is synchronous and throws on error.

See Annotated Example Drawing Object.

bwipjs.raw()

Usage

bwipjs.raw(options)
bwipjs.raw(encoder, text, opts-string)

Invokes the low level BWIPP code and returns the raw encoding data.

This function is synchronous and throws on error.

See Notes on the Raw BWIPP Data.

bwipjs.loadFont()

Usage

bwipjs.loadFont(font-name, width-mult, height-mult, buffer)

• font-name : The name of the font.
• width-mult :
• height-mult : Used to adjust the width and height of the font to better match BWIPP font metrics. A value of 100 means no adjustment. A value less than 100 will decrease the dimension. A value greater than 100 will increase the dimension.
• buffer : Can be a node.js Buffer, a Uint8Array, or a base64 encoded string that contains the font file data.

To use a custom loaded font in your barcode images, you must set the font-name on the following BWIPP options:

• textfont
• addontextfont

addontextfont is only used for ISBN, ISMN, and ISSN barcodes. By default, they are rendered with OCR-A.

You can adjust the size of the font that BWIPP uses via the options:

• textsize
• addontextsize

The size values are in points.

Static Properties

bwipjs.VERSION
bwipjs.BWIPP.VERSION

To Be Documented (bwip-js Internals)

bwipjs.BWIPJS
bwipjs.BWIPP
bwipjs.STBTT
bwipjs.FontLib
bwipjs.DrawingBuiltin(options)
bwipjs.DrawingCanvas(options, canvas)
bwipjs.DrawingZlibPng(options)