Opinionated sorting for TailwindCSS
classes used in HEEx templates and ~H
sigils.
TailwindFormatter
is a mix format
plugin
that sorts TailwindCSS classes found in your templates. It takes
inspiration from Tailwind's official Prettier plugin.
Note: This formatter requires Elixir v1.13.4 or later.
Add tailwind_formatter
to your list of dependencies in mix.exs
:
def deps do
[
{:tailwind_formatter, "~> 0.3.5", only: :dev, runtime: false}
]
end
TailwindFormatter
is most likely to be used alongside Phoenix.LiveView.HTMLFormatter
,
so it should be installed in a way that allows the HTML formatter to
run first, followed by the Tailwind formatter. How this is done
depends on your version of Elixir.
Elixir v1.15 will support
applying multiple plugins to the same file extension type, so the
plugin can be added after the HTML formatter in your .formatter.exs
:
[
plugins: [Phoenix.LiveView.HTMLFormatter, TailwindFormatter],
inputs: [
"*.{heex,ex,exs}",
"priv/*/seeds.exs",
"{config,lib,test}/**/*.{heex,ex,exs}"
],
# ...
]
Current stable versions of Elixir do not support applying multiple
formatter plugins to the same extension type. To overcome this, a
MultiFormatter
is provided that is equivalent to running the
Phoenix.LiveView.HTMLFormatter
first, followed by
TailwindFormatter
.
[
plugins: [TailwindFormatter.MultiFormatter],
inputs: [
"*.{heex,ex,exs}",
"priv/*/seeds.exs",
"{config,lib,test}/**/*.{heex,ex,exs}"
],
# ...
]
If you only want Tailwind class organization and not HTML formatting,
you can simply specify only the TailwindFormatter
:
[
plugins: [TailwindFormatter],
inputs: [
"*.{heex,ex,exs}",
"priv/*/seeds.exs",
"{config,lib,test}/**/*.{heex,ex,exs}"
],
# ...
]
After installation and setup, run mix format
. If you already had
automatic formatting set up (for instance, if your editor is configured
to format your code on save), no changes should be required! Your
Tailwind classes should be happily organized going forward!
If some files are not being formatted as expected, double-check the
:inputs
option in your .formatter.exs
to ensure they are being
matched.
The formatter aims to follow a bundle of rules outlined in the blog post that introduced the official Tailwind Prettier plugin.
- Order classes the same way they are imported in the CSS file: Base, Components, Utilities
- Classes that override other classes appear later in the list
- Classes that impact layout take precedence over classes that decorate
- Plain classes come first before variants (i.e.
focus:
) - Unknown classes are sorted to the front
There are some differences in order to simplify the algorithm and to support Elixir use cases.
With elixir templating one may add an #{inline_elixir_function}
to the class list.
The formatter supports this and sorts these toward the front.
i.e. sm:unknown-class
will still be grouped with the other sm:
variants, even if Tailwind doesn't recognize the class.
In the original spec, 'variants' i.e. sm:hover:
are sorted as though it is one block.
Thus, the order in which they're specified does not matter.
So, for example, a chain of dark:sm:hover:text-gray-600
would be placed toward the end.
In this algorithm, classes are sorted by "layers".
All sm:
variants are grouped together, even if it's a chain of 4 variants.
So for example, dark:sm:hover:text-gray-600
will be placed before any sm:
and hover:
variants, because dark:
has precedence over sm:
and hover:
.
Thus in order to achieve more consistency, the variant chain is ordered.
So, dark:sm:hover:text-gray-600
transforms to sm:dark:hover:text-gray-600
.
Sometimes you may want to dynamically render a class depending on a variable,
i.e. lg:grid-cols-#{@cols}
or alert alert-#{@type}
. The formatter supports
this, and also sorts these toward the front of the variant group it is within.
Note: you will need to define the full class either within the Tailwind safelist or have it fully written out somewhere else in the source file.
So, for example, if @cols = 5
within grid-cols-#{@cols}
, then you will need
grid-cols-5
written in full somewhere in the source so Tailwind won't purge it
in production.
As a bonus this plugin supports the Phoenix variants that ship with new applications.
Otherwise custom classes are not supported at this time. It may be supported in the future.
As this is quite new there may be some Tailwind classes missing.
This project builds heavily off of rustywind and HTMLFormatter.