Recently, I had occasion to complete some coding exercises. Since there was some exposition involved, I wanted to take advantage of some of the affordances for literate programming provided by org-mode in Emacs.

I won’t get too much into the definition and benefits of literate programming here. My intent is to create a reference of some of my favorite org-mode commands that, in practice, I don’t get to use that often; but, would like to have collected in one spot.

Embedding

Images

The caption is added with #+CAPTION: caption text goes here, placed on a line above the image path; the name for the image is done the same way.

#+CAPTION: take your pick – based on work by Renee French
#+NAME: gopher goin'
[[https://blog.golang.org/gopher/usergroups.png]]

The image in the link on the last line could be to a file on the local file system.

It’ll look like this:

image embed be like

And, via the lambda.cx blog, adding the HTML attributes for alt text or title is as simple as using #+ATTR_HTML:

#+ATTR_HTML: :alt this is some alt text
#+ATTR_HTML: :title this is the image title
[[file:image.png]]

An entire file

Let’s say you want to embed an entire file in your output, and use the syntax highlighting for that file type. It’s as simple as using #+INCLUDE:, the path to the file, and then src plus the source code language:

#+INCLUDE: "path/to/file.go" src go

Quickly jump to the file with C-c ', if you like.

Part of a file

More likely, you’ll want to embed part of a file. It’s similar to the previous command, but with a :lines argument followed by which lines to add:

#+INCLUDE: "some/dir/README.org" :lines "4-"

No number after the - will import all lines until the end of the file.

REST calls

This is useful when testing an API that’s in development. I’ve definitely been bitten by accidentally using a newly-outdated curl command from my command line history, and wondering why the response didn’t match what I expected.

After installing ob-restclient.el, it can be used like:

#+begin_src restclient :results value code :exports both
POST http://localhost:8080/api/check
Content-Type: "application/json"

{
  "ipAddress": "0.0.0.1"
}
#+end_src

Kicking off the request with C-c C-c will embed the response below it, looking like:

#+RESULTS:
#+begin_src restclient
{
  "ipAddress": "0.0.0.1",
  "isNewVisitor": true
}
#+end_src

Exporting

Front matter

#+TITLE: Bradfield CSI application

becomes both the <title> in the exported HTML, as well as an h1 tag with the class set to "title".

#+AUTHOR: Chris Boette

becomes a <meta> tag in the exported HTML, with the name attribute set to "Chris Boette", as well as a <p> tag with the class set to "author".

#+DATE: Friday 6 November 12020

becomes a <p> tag with the class date.

#+HTML_HEAD: <style>body { padding: 1rem; } header h1 { font-size: 1.75rem; } h1 { font-size: 1.5rem; } img { max-width: 28rem; } </style>

This one is fun. It allows for the setting of various tags directly in the <head> tag. I chose to augment the existing CSS with some more modern styling conventions.