#barcode API reference

Generate scannable barcodes as images (not printer commands - the complement to label, which emits printer-native barcode commands). encode(data, symbology, opts) -> Symbol builds a device-independent representation - a black/white module matrix for 2D codes, a run of bar widths for 1D codes - and the renderers turn a Symbol into output: svg (resolution-independent, embeds in HTML / email), png (a monochrome PNG hand-encoded over compress + crc, no image library), terminal (Unicode half-block art), and matrix (the raw cells).

Symbologies: 2D qr (Reed-Solomon over GF(256), EC levels L/M/Q/H, automatic version selection 1-40, data-mask scoring, and numeric / alphanumeric / byte mode chosen for compactness) and datamatrix (ECC200, square symbols 10x10 to 26x26); 1D code128, code93, ean13, ean8, upca, upce, itf, code39, and gs1-128 (FNC1 + Application Identifiers). A 1D SVG also carries a human-readable text line (Options.humanReadable). Pure .j over compress (zlib) + crc (CRC-32) + encoding + the bitwise operators; runs on both binaries.

Import with import "barcode.j" as barcode;. See the barcode guide for prose and examples.

#Functions

#barcode.defaults()

Sensible default rendering options (scale 8, quiet 4, EC level M, black on white). Scale 8 (8 px per module / narrow bar) keeps a code comfortably scannable off a screen by a phone camera, where a smaller render invites focus and moire trouble; drop opts.scale for a more compact image.

Returns {Options} - the defaults

#barcode.encode(data as string, symbology as string, opts as Options)

Encode data as a symbol of the given symbology. 2D: "qr", "datamatrix". 1D: "code128", "code93", "ean13", "ean8", "upca", "upce", "itf", "code39", "gs1-128".

Parameters

• data {string} - the payload
• symbology {string} - the symbology
• opts {Options} - rendering / EC options (uses ecLevel for QR)

Returns {Symbol} - the encoded symbol

Throws

• {Error} - kind "barcode" on an unknown symbology or invalid data

#barcode.matrix(symbol as Symbol)

The raw cells of a 2D symbol.

Parameters

• symbol {Symbol} - a matrix symbol

Returns {list of list of bool} - the module grid (true = dark)

#barcode.png(symbol as Symbol, opts as Options)

Render a symbol as a monochrome (grayscale) PNG.

Parameters

• symbol {Symbol} - the symbol
• opts {Options} - scale / quiet / height

Returns {bytes} - the PNG image

#barcode.svg(symbol as Symbol, opts as Options)

Render a symbol as an SVG string.

Parameters

• symbol {Symbol} - the symbol
• opts {Options} - scale / quiet / height / colours

Returns {string} - the SVG document

#barcode.terminal(symbol as Symbol)

Render a symbol as Unicode half-block art for a terminal (2D only).

Parameters

• symbol {Symbol} - a matrix symbol

Returns {string} - the terminal rendering

#Structs

#barcode.Options

Rendering options.

#barcode.Symbol

A device-independent encoded symbol.

#Enums

#barcode.SymbolKind

The kind of an encoded symbol: Matrix (a 2D module grid, e.g. QR) or Linear (a 1D run of bar / space widths).