Rails-LaTeX

Git: github.com/baierjan/rails-latex
Original author: Geoff Jacobsen
Copyright: 2010-2015 Geoff Jacobsen, Jan Baier and contributors
License: MIT-LICENSE

Description

rails-latex is a renderer for rails, which allows tex files with erb to be turned into an inline pdf.

Synopsis

app/helpers/application_helper.rb:

def lesc(text)
  LatexToPdf.escape_latex(text)
end

app/views/stories/show.html.erb:

...
<%= link_to "print", story_path(@story,:format => :pdf) %>

app/views/stories/show.pdf.erb:

...
<%= lesc @story.name % >

app/views/layouts/application.pdf.erbtex:

\documentclass[12pt,a4paper,sloppy,< %= @landscape % >]{article}
...
< %= yield % >
\end{document}

config/initializers/mime_types.rb:

...
Mime::Type.register "application/pdf", :pdf, ['text/pdf'], ['pdf']

Only the file containing the \documentclass should be of type: .pdf.erbtex . Partials and views (when there is a layout) should be of type .pdf.erb .

If a LaTeX package requires more than one parser run add the following to the .pdf.erbtex file:

<% @latex_config={:parse_runs => 3} %>

You can override the defaults like so:

LatexToPdf.config.merge! :command => 'xetex', :arguments => ['-etex'], :parse_runs => 2

or to change just the arguments:

LatexToPdf.config[:arguments].delete('-halt-on-error')

The defaults are:

command: 'pdflatex'
arguments: ['-halt-on-error']
parse_runs: 1

The last log file is moved to tmp/rails-latex/input.log , and the corresponding source TeX file to tmp/rails-latex/input.tex . If the PDF is not produced the build directory is not removed; an archive script should be written to occasionally clean up the tmp/rails-latex directory.

See the rails application under examples/rails-latex-demo/ for a working example.

Generating a String

If you need to generate the LaTeX document as a string you can use the render_to_string method. You will probably need to pass the :layout => true option to invoke the PDF generator. Here is an example to generate an email attachment:

In the controller you will have something along the lines of:

def send_email_method
  output = render_to_string(:template => "/your_model/your_view.pdf.erb", :layout => true)
  MyMailer.email_sender(current_user, output).deliver
end

The thing to note is the :layout => true which is needed so that the pdf template can grab the application erbtex layout. Then in your mailer:

def email_sender(user, pdf_attachment)
  @user = user
  attachments["attachment_name.pdf"] = {:mime_type => 'application/pdf', :content => pdf_attachment}
  mail( .... )
end

Exception handling and debugging

When LaTeX render fails, RailsLatex::ProcessingError is thrown. In your code, you can catch it and react according to your needs. To make your life easier, TeX source and log are attached to the exception as instance variables src and log.

Requirements

ruby 1.8 or 1.9
rails 3 or later

Install

gem install rails-latex

Development

Developing rails-latex requires bundler and RedCloth

rake test
rake build

Contributions

Geoff Jacobsen
Tommaso Patrizi
Klaus Reske
Jan Baier
Jakub Cerny