Jinja template indenter (original) (raw)

DjHTML

A pure-Python Django/Jinja template indenter without dependencies.

{% block content %}

{% blocktranslate trimmed %} Don't you hate code that's not properly indented? {% endblocktranslate %}

{% endblock %}

DjHTML indents mixed HTML/CSS/JavaScript templates that containDjangoor Jinja template tags. It works similar to other code-formatting tools such asBlack and interoperates nicely withpre-commit.

DjHTML is an indenter and not a formatter: it will only add/remove whitespace at the beginning of lines. It will not insert newlines or other characters. The goal is to correctly indent already well-structured templates, not to fix broken ones.

Installation

DjHTML requires Python 3.9 or higher and is compatible with all operating systems supported by Python. Install DjHTML with the following command:

Note thatWindows still uses legacy code pagesinstead of UTF-8. It is highly advised to set the environment variablePYTHONUTF8 to 1 with thesetxcommand:

C:\> setx /m PYTHONUTF8 1

Usage

After installation you can indent templates using the djhtmlcommand:

$ djhtml template.html
reindented template.html
1 template has been reindented.

You can also run djhtml . to indent all HTML files beneath the current directory.

An exit status of 0 means that everything went well, regardless of whether any files were changed. When the option -c / --check is used, the exit status is 1 when one or more files would have changed, but no changes are actually made. All available options are given bydjthml -h / djthml --help.

`fmt:off` and `fmt:on`

You can exclude specific lines from being processed with the{# fmt:off #} and {# fmt:on #} operators:

{# fmt:off #} ,-.|
/ .
_,--./ {# fmt:on #}

Contents inside <pre> ... </pre>, , /* ... */, and{% comment %} ... {% endcomment %} tags are also ignored (depending on the current mode).

Modes

The indenter operates in one of three different modes:

DjHTML mode: the default mode. Invoked by using the djhtml command or the pre-commit hook.
DjCSS mode. Will be entered when a <style> tag is encountered in DjHTML mode. It can also be invoked directly with the commanddjcss.
DjJS mode. Will be entered when a <script> tag is encountered in DjHTML mode. It can also be invoked directly with the commanddjjs.

pre-commit configuration

A great way to use DjHTML is as a pre-commithook, so all your HTML, CSS and JavaScript files will automatically be indented upon every commit.

First, install pre-commit:

$ pip install pre-commit
$ pre-commit install

Then, add the following to your .pre-commit-config.yaml:

repos:

repo: https://github.com/rtts/djhtml rev: 'main' # replace with the latest tag on GitHub hooks:
- id: djhtml
- id: djcss
- id: djjs

Now run pre-commit autoupdate to automatically replace main with the latest tag on GitHub,as recommended by pre-commit.

If you want to override a command-line option, for example to change the default tabwidth, you change the entry point of these hooks:

hooks:
  - id: djhtml
    # Use a tabwidth of 2 for HTML files
    entry: djhtml --tabwidth 2
  - id: djcss
  - id: djjs

If you want to limit the files these hooks operate on, you can usepre-commit mechanisms for filtering. For example:

hooks:
  - id: djhtml
    # Indent only HTML files in template directories
    files: .*/templates/.*\.html$
  - id: djcss
    # Run this hook only on SCSS files (CSS and SCSS is the default)
    types: [scss]
  - id: djjs
    # Exclude JavaScript files in vendor directories
    exclude: .*/vendor/.*

Now when you run git commit you will see something like the following output:

$ git commit

DjHTML...................................................................Failed
- hook id: djhtml
- files were modified by this hook

reindented template.html
1 template has been reindented.

To inspect the changes that were made, use git diff. If you are happy with the changes, you can commit them normally. If you are not happy, please do the following:

Run SKIP=djhtml git commit to commit anyway, skipping thedjhtml hook.
Consider opening an issuewith the relevant part of the input file that was incorrectly formatted, and an example of how it should have been formatted.

Your feedback for improving DjHTML is very welcome!

Development

First of all, clone this repository:

$ git clone https://github.com/rtts/djhtml
$ cd djhtml

Then, create a Python virtualenv and activate it:

$ python -m venv ~/.virtualenvs/djhtml
$ . ~/.virtualenvs/djhtml/bin/activate

Then, install the package in development modeincluding the dev dependencies, and install the pre-commit hooks:

$ python -m pip install -e '.[dev]'
$ pre-commit install --install-hooks

You can run the unittests with:

Or use nox to test all supported Python interpreters:

Finally, to get a little insight into the tokenization step of the indenting algorithm, you can run DjHTML with the -d / --debugargument. You will see a Python representation of the tokens that are created.