CrissCross

CrissCross is a Markdown-centric templating engine for offline documents.

Some of its features:

• Replace Mustache-style placeholders
• Include/import subfiles !INCLUDE "subfile.md"
• Convert to other formats using pandoc or rmarkdown

Getting Started

Prerequisites

• Python 3
• (optional) either pandoc or rmarkdown is required to convert files from one format to another
• (optional) LaTeX is required for PDF generation

Installation

pip3 install crisscross

Examples

Here are some sample use cases of CrissCross, ordered by increasing complexity.

• English and Spanish: Generate PDFs of the same file with keywords in different languages.
• PhD Applications: Generate personal statements customized for different schools.
• Weekly Quiz: Generate quizzes and their solutions for 2 different sections using the same template.
  • The examples uses crisscross combine to take the "Cartesian product" of different sets of YAML metadata files, and crisscross process to generate PDF files from them.

Here's a sneak peek of the PhD applications example. CrissCross allows you to go from a template that looks like this:

I am applying to **{{school_alt_name}}**’s PhD program because **{{school}}** is awesome. 

!INCLUDE "custom/{{school}}_last.md"

To PDFs like these:

Michigan	UChicago

Usage

Commands

There are two commands, process and combine.

Process

process is the command that processes the template files.

Example

Convert TEMPLATE.md into PDF, using key-value pairs specified in VARS.yaml:

crisscross process TEMPLATE.md -y VARS.yaml -o OUTDIR/TEMPLATE.pdf

Options

Usage: crisscross process [OPTIONS] TEMPLATES...

  Preprocess text files, and render with pandoc or rmarkdown.

Options:
  -y, --yaml PATH                 The YAML file(s) to be used. If wildcard
                                  characters are used, then the whole argument
                                  must be quoted, e.g., -y '*.yaml'.
                                  (Default: custom/*.yaml)
  --no-yaml                       Use no YAML files. In this case, key-value
                                  pairs must be supplied with -k --key-value.
                                  (Default: disabled)
  -o, --out PATH                  Schema for the path to an output file.
                                  Variables are accepted. 
                                  (Default:
                                  docs/{{id}}.pdf)
  --open-ren / --no-open-ren      Whether to open the rendered files
                                  automatically. 
                                  (Default: enabled)
  --open-text / --no-open-text    Whether to open the generated text files
                                  automatically. 
                                  (Default: disabled)
  -a, --args TEXT                 A string of arguments to be passed on to
                                  pandoc. Passing arguments to rmarkdown not
                                  supported. If there are spaces, the string
                                  should be quoted.
  -r, --render [pandoc|rmarkdown]
                                  Render using vanilla pandoc or rmarkdown, or
                                  do not render at all. 
                                  (Default: pandoc)
  --no-render                     Do not render the files with pandoc or
                                  rmarkdown. Only do variable substitution or
                                  file inclusion. 
                                  (Default: disabled)
  --include-tag [include|import]  Syntax for file inclusion. Either !INCLUDE
                                  "filename" or @import "filename". 
                                  (Default:
                                  include)
  -V, --variable TEXT             A key-value pair separated by ":". No spaces
                                  allowed. Can be used in conjunction with or
                                  in place of YAML files.
  -f, --force                     Suppress warnings. 
                                  (Default: disabled)
  -q, --quiet / -v, --verbose     Suppress messages. 
                                  (Default: disabled)
  -h, --help                      Show this message and exit.

Combine

combine is a helper command takes the "Cartesian product" of lists of files.

Example

crisscross combine a1,a2 b1,b2 -o out/

would generate under out/

out/
  a1_b1
  a1_b2
  a2_b1
  a2_b2

where a1_b1 is a concatenation of a1 and b1, a1_b2 a concatenation of a1 and b2, and so on.

See the quiz example for a real-world use case of combine.

Options

Usage: crisscross combine [OPTIONS] [FILES]...

  Generate the 'Cartesian product' of multiple files.

Options:
  -o, --out DIRECTORY          Output directory.
  -s, --separator TEXT         Character used to join the names of input
                               files.
  -q, --quiet / -v, --verbose  Suppress messages. 
                               (Default: disabled)
  -h, --help                   Show this message and exit.

File Inclusion

Two inclusion tags are supported:

• !INCLUDE "foo.md", in the style of Markdown Preprocessor, and
• @import "foo.md", in the style of Markdown Preview Enhanced
  • However, unlike MPE, CrissCross does not support <!-- @import "foo.md" -->.

Adding asis after the inclusion tag will tell CrissCross to include the file as is, and not to further process it: !INCLUDE asis "foo.md"

Key-Value Pairs

Key-value pairs tell CrissCross how to replace placeholder expressions. They can be either placed in YAML files:

lang: English
level: Level

Alternatively, they could be supply using the -V option:

crisscross process -V key1:value1 -V key2:value2 TEMPLATE -o OUTFILE

Roadmap

• [ ] Add the option to render inline placeholders as is
• [ ] Add the option to use different patterns for placeholder expressions
• [ ] Add logic support

Built With

This project uses the following open source libraries.

• pallets/click: Python composable command line interface toolkit
• hackebrot/poyo: A lightweight YAML Parser for Python
• noahmorrison/chevron: A Python implementation of mustache

Acknowledgments

This project is heavily inspired by:

• alpianon/include-pandoc: A wrapper for pandoc to pre-process includes
• michaelstepner/pandoc-mustache: Pandoc filter for variable substitution using Mustache syntax

Other related projects

• jreese/markdown-pp: Preprocessor for Markdown files to generate a table of contents and other documentation needs
• DCsunset/pandoc-include: Pandoc filter to allow file includes
• owickstrom/pandoc-include-code: A Pandoc filter for including code from source files
• MrToph/pandoc-code-file-filter: A filter for pandoc to include sections of code from a file