postcss-pseudo-class-enter

Pseudo Class Enter

Pseudo Class Enter is a PostCSS plugin that allows you to use the proposed :enter pseudo-class in CSS.

:enter simplifies selectors targeting elements that are designated, as the naming of :hover is somewhat misleading; it specifically means elements designated with a pointing device, rather than any device.

/* before */

nav :enter > span {
    background-color: yellow;
}

/* after */

nav :hover > span,
nav :focus > span {
    background-color: yellow;
}

From the proposal:

The :enter pseudo-class applies while the user designates an element with a keyboard, pointing device, or other form of input. It matches an element if the element would match :focus or :hover.

Usage

Follow these steps to use Pseudo Class Enter.

Add Pseudo Class Enter to your build tool:

npm install postcss-pseudo-class-enter --save-dev

Node

require('postcss-pseudo-class-enter')({ /* options */ }).process(YOUR_CSS);

PostCSS

Add PostCSS to your build tool:

npm install postcss --save-dev

Load Pseudo Class Enter as a PostCSS plugin:

postcss([
    require('postcss-pseudo-class-enter')({ /* options */ })
]);

Gulp

Add Gulp PostCSS to your build tool:

npm install gulp-postcss --save-dev

Enable Pseudo Class Enter within your Gulpfile:

var postcss = require('gulp-postcss');

gulp.task('css', function () {
    return gulp.src('./css/src/*.css').pipe(
        postcss([
            require('postcss-pseudo-class-enter')({ /* options */ })
        ])
    ).pipe(
        gulp.dest('./css')
    );
});

Grunt

Add Grunt PostCSS to your build tool:

npm install grunt-postcss --save-dev

Enable Pseudo Class Enter within your Gruntfile:

grunt.loadNpmTasks('grunt-postcss');

grunt.initConfig({
    postcss: {
        options: {
            processors: [
                require('postcss-pseudo-class-enter')({ /* options */ })
            ]
        },
        dist: {
            src: 'css/*.css'
        }
    }
});

Options

prefix

Type: String
Default: -

Adds the prefix surrounded by dashes before the pseudo-class.

outline

Type: String
Default: unset

Adds an outline declaration to matching rules when an existing one does not already exist.

Alternatives

Below are some other methods to recreate the effects of :enter.

Use @custom-selector (supported nowhere yet)

@custom-selector :--enter :focus, :hover;

:--enter { /* ... */ }

Use :matches (supported in Firefox 4+, Chrome 12+, Opera 15+, Safari 5.1+)

:matches(:focus, :hover) { /* ... */ }

Use :focus and :hover (supported everywhere)

:focus, :hover { /* ... */ }

Use Sass mixins (requires preprocessing)

@mixin -enter { &:focus, &:hover { @content; } }

@include -enter { /* ... */ }