Elixir2pdf

Elixir2pdf is a simple Elixir wrapper for ErlGuten, a Erlang PDF generation application. It is limited to my current needs of ErlGuten's functionality as well as some additional functionality not provided by ErlGuten.

Installation

The package can be installed via GitHub:

def deps do
  [{:elixir2pdf, github: "jsonkenl/elixir2pdf"}]
end

Basic Usage

PDF files have the following basic properties:

• The origin {0, 0} of a given document is the bottom-left corner. The x-axis extends to the right and the y-axis extends upward.
• Locations and sizes are stored as a PDF unit. Each PDF unit is equal to 1/72 of an inch. For example, the coordinate point {72, 72} is located 1 inch to the right of the left edge of the page and 1 inch above the bottom edge of the page.
• PDF documents are sized according to their media box and crop box values. The media box is the total size of the document while the crop box is the viewable area. While most PDF documents have the same media box and crop box values, this is important to note because the origin {0, 0} is in relation to the media box as opposed to the viewable area of the crop box.

Elixir2pdf works by creating a PDF GenServer process and utilizing various functions to add objects to the state of said process and ultimately exporting the data to a PDF document. See below for a list of ErlGuten functionality currently exposed and an example. Follow the links to view details for each function.

Current Exposed Functions:

General

• new/1
• close/1

Document

• set_new_page/1
• export/2

Text

• set_font/3
• text/4
• right_aligned_text/5
• center_aligned_text/6

Graphics

• draw_line/5
• draw_rectangle/5
• insert_image/4

Example:

defmodule Example do
  import Elixir2pdf

  @font1 {"OCR-B-Digits", 10}
  @font2 {"Times-Roman", 6}
  @font3 {"Courier-Bold", 12}
  @font4 {"Times-Roman", 5}
  @font5 {"OCR-A-Digits", 10}

  def check_template do
    pid = new

    pid
    |> draw_rectangle({85,675}, {300, 125}, 0.5)
    |> set_font(@font1, :blue)
    |> right_aligned_text(@font1, 375, 785, "1025")
    |> set_font(@font2)
    |> right_aligned_text(@font2, 300, 765, "DATE")
    |> draw_line({305, 765}, {355, 765}, 0.5)
    |> text(90,750, "PAY TO THE")
    |> text(90,745, "ORDER OF")
    |> draw_line({125, 745}, {315, 745}, 0.5)
    |> draw_line({315,745}, {315, 750}, 0.5)
    |> set_font(@font3)
    |> text(320, 745, "$")
    |> draw_rectangle({330, 742}, {45, 13}, 1, :antiquewhite4)
    |> draw_line({95, 727}, {320, 727}, 0.5)
    |> set_font(@font2)
    |> text(325, 727, "DOLLARS")
    |> set_font(@font4)
    |> text(90, 695, "MEMO")
    |> draw_line({110, 695}, {220, 695}, 0.5)
    |> draw_line({240, 695}, {375, 695}, 0.5)
    |> set_font(@font5)
    |> text(110, 680, "000000000  000000000    1025")
    |> export("./example.pdf")
    |> close
  end
end

Contributing

Contributions are encouraged. Feel free to fork the repo, add your code along with appropriate tests and documentation (ensuring all existing tests continue to pass) and submit a pull request.