prettier-django.md

Running Prettier against Django or Jinja templates

I really like auto-formatting tools like Black. I've been hoping to find one that works with Django and Jinja templates for years.

Today I managed to get excellent JavaScript Prettier formatter to run against a Jinja template file using the prettier-plugin-jinja-template plugin by David Odenwald.

I had a bit of a fiddle getting it to work because I'm still not fluent in npm/npx, but the recipe I used was the following.

1. Install prettier and prettier-plugin-jinja-template in a directory somewhere. This command will create a package.json and package-lock.json and a a whole node_modules/ folder - the full install adds up to 8.4M:

   npm i prettier prettier-plugin-jinja-template

2. In that directory run this command:

   npx prettier --plugin=prettier-plugin-jinja-template \
     --parser=jinja-template \
     --write path/to/your/template.html

   The --write option will rewrite the template in place.

I first tried using npm i -g prettier prettier-plugin-jinja-template to install the application once, globally, but I couldn't work out how to get the plugin working that way.

Instead, I've added it to my path another way. I already have a ~/.local/bin/ directory that is on my $PATH, so I ran the npm i command from above in that folder and then added this script there, in a file called pretty-templates.sh (created with the help of Claude):

#!/bin/bash

# Check if at least one argument is provided
if [ $# -eq 0 ]; then
    echo "Error: At least one argument is required."
    exit 1
fi

# Store the current directory
original_dir=$(pwd)

# Change directory to ~/.local/bin/
cd ~/.local/bin/ || exit

# Convert all paths to absolute paths
args=()
for arg in "$@"; do
    args+=("$original_dir/$arg")
done

# Run the prettier command with the absolute paths
npx prettier --plugin=prettier-plugin-jinja-template \
    --parser=jinja-template \
    --write "${args[@]}"

Now I can run that command from anywhere on my computer:

prettier-templates.sh templates/team_backups.html

Alternatives

Jeff Triplett pointed me to two pure Python alternatives:

• curlylint is "experimental HTML templates linting for Jinja, Nunjucks, Django templates, Twig, Liquid" - pip install curlylint then curlylint my/templates
• DjHTML is "a pure-Python Django/Jinja template indenter without dependencies" - pip install djhtml then djhtml template.html