xeerpe

CSS backgrounds in Gleam: gradients, patterns, effects, animations and a lot of presets. A binding for xeerpe, with xeerpe bundled (no npm needed).

Demo · Docs · xeerpe.io

gleam add xeerpe

import lustre/attribute
import lustre/element/html
import xeerpe
import xeerpe/css
import xeerpe/quick

fn sky() {
  xeerpe.new()
  |> quick.linear("#FFB347", "#4A1942", deg: 170.0)
  |> quick.vignette(0.3, "#1a0b1f")
  |> quick.grain(3.0)
  |> quick.breathe("6s")
}

pub fn view() {
  html.div([attribute.styles(css.properties(sky()))], [])
}

Made for Lustre. It only produces CSS, so it works with anything on the JavaScript target.

Modules

• xeerpe: every xeerpe call, same names in snake_case (linearGradient → linear_gradient).
• xeerpe/quick: short versions of the common calls.
• xeerpe/css: properties for attribute.styles, text_properties for gradient text, inline for a style string. Keyframes for animations are added to the page automatically.
• xeerpe/colors: xeerpe's palette.

All the options

quick takes the usual arguments. For everything else, call xeerpe with an options record. Every record has a default to start from:

xeerpe.new()
|> xeerpe.linear_gradient(
  xeerpe.LinearGradientOptions(
    ..xeerpe.linear_gradient_options,
    from: Some("#FFB347"),
    to: Some("#4A1942"),
    angle: Some(xeerpe.Deg(170.0)),
  ),
)

Presets

let assert Ok(gold) = xeerpe.preset("gold")
gold |> quick.grain(2.0)

xeerpe.preset_names() lists all, xeerpe.preset_categories() groups them.

Builders are data

A Builder is just a list of calls. Nothing runs until css.properties. Keep one in your model, compare with ==, extend without changing the original.

Using another xeerpe

The bundled xeerpe is version xeerpe.bundled_version. To run a different one:

npm install xeerpe@<version>

// src/my_xeerpe.mjs
import * as xeerpe from "xeerpe";
export const module = () => xeerpe;

@external(javascript, "./my_xeerpe.mjs", "module")
fn my_xeerpe() -> Dynamic

pub fn main() {
  let assert Ok(Nil) = xeerpe.use_module(my_xeerpe())
  // start your app
}

This changes behaviour only. The Gleam API stays the one of the bundled version. xeerpe.use_bundled() switches back.

Quirks

In xeerpe 1.0.2:

• breathe, aurora and liquid resize every layer, so patterns stretch.
• Animation direction only works with pulse and aurora.
• DotsOptions.style and GrainOptions.animated do nothing.
• An animated gradient may show a thin line on one edge. Add background-repeat: no-repeat.

Development

npm install --prefix test/npm-xeerpe   # xeerpe from npm, the tests compare against it
gleam test
gleam run -m lustre/dev start xeerpe_dev   # demo, add #reference for every option
scripts/update-xeerpe.sh [version]         # bundle a new xeerpe release
scripts/build-site.sh                      # demo site into dist/

Credits

xeerpe by Nicola Centonze does all the work; this is a Gleam wrapper around it, bundling its index.mjs under MIT. The pink logo is a parody of xeerpe's green one, not the official one.