Iona

Document generation from Elixir, using LaTeX.

Highlighted Features

• Generate professional-quality typeset .pdf (and .dvi) documents using LaTeX, and support defining your own TeX processors for different formats.
• Built-in support for EEx templating with automatic escaping and a custom helpers
• Preprocessing support (multiple runs for bibliographies, etc)
• Optionally generating a prepared directory with a build.sh script for final processing.

Prerequisites

While features are on the roadmap to ease authorship of .tex documents, at the current time knowledge of LaTeX is assumed (or at least a basic willingness to wade into that very deep topic).

We recommend you start your knowledge quest at the LaTeX homepage.

Installation

Add as a dependency to your mix.exs:

def deps do
  [
    iona: "~> 0.4"
  ]
end

Install it with mix deps.get and don't forget to add it to your applications list if using an older version of Elixir:

def application do
  [applications: [:iona]]
end

LaTeX

Of course you need a TeX system installed, including latex, pdflatex, or any other variants you'd like to use to process your .tex source into final documents. (The default configuration assumes pdflatex is installed for PDF generation and latex is installed for DVI generation. See "Configuration," below.)

You can download and install a TeX system at the LaTeX Project website -- or using the the package management system of your choice.

Examples

From TeX source

Generate a PDF from an existing .tex source:

Iona.source(path: "simple.tex")
|> Iona.write!("/path/to/document.pdf")

You can also use a binary string:

Iona.source("\documentclass[12pt]{article} ...")
|> Iona.write!("/path/to/simple.pdf")

More complex preprocessing needs for citations and bibliographies? Define the prepocessing pipeline:

Iona.source(path: "academic.tex")
|> Iona.write!("/path/to/academic.pdf",
               preprocess: ~w(latex bibtex latex))

To generate a directory with a build script that can be run to finalize the build, use :prepare:

Iona.source(path: "academic.tex")
|> Iona.write!("/path/to/academic.pdf",
               preprocess: ~w(latex bibtex latex),
               prepare: "/path/to/prepared/directory")

Want to get the raw document content as a binary? Use to:

Iona.source(path: "fancy.tex")
|> Iona.to(:pdf)
|> MyModule.do_something_with_pdf_string

Complex preprocessors

You can provide functions in the preprocessing pipeline too. The function will be invoked, given the temporary directory processing is occuring and the basename of the original file (eg, "source.tex"):

Iona.source(path: "source.tex")
|> Iona.write!("/path/to/source.pdf",
               preprocess: [fn (directory, filename) -> :ok end])

Function preprocessors should return:

• :ok if processing should continue
• {:shell, command} to indicate a command should be run as a preprocessor (see example below)
• {:error, reason} if processing should halt

If given {:shell, command}, Iona will execute that command as a preprocessor. This is especially useful for interpolation, eg:

knitr = fn (_, filename) ->
  {:shell, "R -e 'library(knitr);knitr(\"#{filename}\");'" }
end

Iona.source(path: "graphs.Rnw")
|> Iona.write!("/path/to/graphs.pdf",
               preprocess: [knitr])

Important: As always, only interpolate trusted input into shell commands.

From an EEx TeX template

%{title: "My Document"}
|> Iona.template(path: "/path/to/template.tex.eex")
|> Iona.write("/path/to/my_document.pdf")

Values are inserted into EEx with, eg, <%= @title %> after being automatically escaped by Iona.Template.Helper.escape/1.

If you're confident values are safe for raw insertion into your LaTeX documents (or you'd like to support insertion of LaTeX commands), use raw/1, made available by default as part of Iona.Template.Helper:

For instance, if you wanted to style @title as boldface, you could pass it as "{\bf My Document}" and insert it as a raw string:

<%= raw @title %>

With Custom Helpers

You can import additional helper modules for use in your templates by two methods.

The first (and preferred) method is by overriding the :helpers application configuration setting (see "Configuration," below).

You can also pass a :helpers option to Iona.template/1 with a list of additional helpers:

%{title: "My Document"}
|> Iona.template(path: "/path/to/template.tex.eex",
                 helpers: [My.Custom.HelperModule])
|> Iona.write("/path/to/my_document.pdf")

Note in this case the setting is additive; the list is concatenated with the :helpers defined in the application configuration.

Configuration

The default, out-of-the-box settings for Iona are equivalent to the following Mix config:

config :iona,
  helpers: [Iona.Template.Helper],
  preprocess: [],
  processors: [pdf: "pdflatex", dvi: "latex"]

Note you can also pass a :preprocess and :processor options to define a preprocessing pipeline on a case-by-case basis. See the examples above or the documentation for Iona.to/3 and Iona.write/3.

License

See LICENSE.

LaTeX

LaTeX is free software, and is not distributed with this (unaffiliated) project. Please see the LaTeX homepage for more information.