@spec create(String.t(), level(), mode()) :: Result.t(String.t(), t())

Creates QR code. You can change the error correction level according to your needs. There are four level of error correction: :low | :medium | :quartile | :high where :low is default value.

This function returns Result, it means either tuple of {:ok, QR.t()} or {:error, "msg"}.

Example:

iex> QRCode.QR.create("Hello World")
{:ok,
%QRCode.QR{
  ecc: %QRCode.ErrorCorrection{
    blocks_in_group1: 1,
    blocks_in_group2: 0,
    codewords: {[[139, 194, 132, 243, 72, 115, 10]], []},
    codewords_per_block_in_group1: 19,
    codewords_per_block_in_group2: 0,
    ec_codewrods_per_block: 7,
    groups: {[
        [64, 180, 134, 86, 198, 198, 242, 5, 118, 247, 38, 198, 64, 236, 17,
        236, 17, 236, 17]
      ], []}
  },
  ecc_level: :low,
  encoded: <<64, 180, 134, 86, 198, 198, 242, 5, 118, 247, 38, 198, 64, 236,
    17, 236, 17, 236, 17>>,
  mask_num: 0,
  matrix: [
    [1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1],
    [1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1],
    [1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1],
    [1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1],
    [1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1],
    [1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1],
    [1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1],
    [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0],
    [1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0],
    [0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1],
    [1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1],
    [0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0],
    [1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0],
    [1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1],
    [1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1],
    [1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0],
    [1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0],
    [1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1],
    [1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0],
    [1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 1]
  ],
  message: <<64, 180, 134, 86, 198, 198, 242, 5, 118, 247, 38, 198, 64, 236,
    17, 236, 17, 236, 17, 139, 194, 132, 243, 72, 115, 10>>,
  mode: :byte,
  orig: "Hello World",
  version: 1
}}

For saving QR code to svg file, you have to render it first and then save it:

iex> qr = QRCode.QR.create("Hello World", :high)
iex> qr |> QRCode.render() |> QRCode.save("hello.svg")
{:ok, "hello.svg"}

The svg file will be saved into your project directory.

@spec create!(String.t(), level(), mode()) :: t()

The same as create/2, but raises a QRCode.Error exception if it fails.