slacktex

An API server for integrating LaTeX formulas into Slack. (What is Slack?)

About

This API accepts requests originating from a Slack slash command. The slash command input is expected to be properly formatted LaTeX formula code. From the code, it generates images and places them in a user specified directory. It then generates a URL for the image and POSTs back to Slack with the link.

Prerequisites

• Linux
• Apache or nginx
• node
• dvipng
• latex

Setup

First things first, run the following:

$ ./configure
$ npm install

Configuration

You'll need to add two things to slack:

• A slash command
• An incoming webhook

While setting those up, you'll need to determine certain configuration values that are also needed for slacktex. The default configuration is located in config/default.json. To customize this simply make a copy of the file and customize it.

$ cd config
$ cp default.json local.json

Configuration File

Server

{
  "server": {
    "host": "example.com",
    "port": 8000,
    "request_path": "/command",
    "output_path": "",
    "output_dir": "",
    "temp_dir": "/tmp",
    "output_tex": ""
  }
}

property	description
host	The hostname of the server that will accept the API requests
port	The port to bind to
request_path	The HTTP path that will accept requests, all other paths will 404
output_path	The HTTP path that will be used to generate image links, in addition to the host
output_dir	The filesystem location where the images will be put
temp_dir	The temporary directory where the API will work; this must exist
output_tex	If set to 'true', outputs the tex file also. (filename: file.png.tex)

Slack

{
  "slack": {
    "token": "",
    "command": "/command",
    "webhook_url": "",
    "link_text": ""
  }
}

property	description
token	The token string coming from Slack along with the request
command	The slash command set up in Slack sent with the request
webhook_url	The Slack incoming webhook url to POST back to after generating the image
link_text	The text to display on Slack as the link description. If empty, the given latex input will be used

PNG

{
  "png": {
    "bin": "/usr/bin/dvipng"
  }
}

property	description
bin	The file system path of the dvipng binary that converts and trims the DVI file generated by LaTeX

Tex

{
  "tex": {
    "bin": "/usr/bin/latex",
    "template": "./resource/template.tex"
  }
}

property	description
bin	The file system path of the LaTeX binary
template	The file system path of the LaTeX template used for generating the images