PostCSS Prepend Selector

[PostCSS] plugin Prepend selector for each rule with optional exclude existing selector from prepending.

[PostCSS]: Version 8 https://github.com/postcss/postcss

The intention

The intention I had extended the plugin to create a user interface for the web using Vue-js and styled it with Tailwind-css. The Vue-js panel was integrated into an existing website/application. So the styles created with Tailwind-css should be used exclusively in the Vue-js application.

That means this plugin is not really well developed. However, it serves its purpose without claiming to be a really well-tested script.

Usage in postcss.config.js with prepend-selector-postcss

// postcss.config.js
const autoprefixer = require('autoprefixer');
const tailwindcss = require('tailwindcss');
// https://github.com/ledniy/postcss-prepend-selector
const prepend = require('prepend-selector-postcss')({
    // requiured
    selector: '.myPrefix ',
    // optional can be omitted
    exclude: ['.living_classname_to_prevent_from_prefixing '],
    // optional can be omitted
    excludePart: ['.grid-'],
    // optional can be omitted -> body{some unwanted global reset stuff}  -> body .selector{some unwanted global reset stuff}
    appendTo:['body'],
    // optional can be omitted -> Prefixing special selectors with a string that not exists in html tags to prevent using "body" - selector
    // body{some unwanted global reset stuff}  -> i_had_made_invalid_body{some unwanted global reset stuff}
    makeInvalid: {
        selectors:     ['body'],
        invalidPrefix: 'i_had_made_invalid_'
    }
})
module.exports = {
    purge  : [
        './public/**/*.html',
        './src/**/*.{js,jsx,ts,tsx,vue}',
    ],
    plugins: [
        tailwindcss,
        prepend,
        autoprefixer,
    ],
};

Prefix all

// minimal example
postcss([require('prepend-selector-postcss')({
    selector: '.myPrefix '
})])

Original Css

.foo {
    /* Input example */
}

.foo, .bar {
    /* Input example */
}

Result

.myPrefix .foo {
    /* Output example */
}

.myPrefix .foo, .myPrefix .bar {
    /* Output example */
}

Prefix all but exclude something

// example with exclude
postcss([require('prepend-selector-postcss')({
    selector: '.myPrefix ',
    exclude : ['#living_id_prefix_to_prevent_from_prefixing ', '.living_classname_to_prevent_from_prefixing '],
})])

Original Css

.foo {
    /* Input example */
}

.foo, .bar {
    /* Input example */
}

#living_id_prefix_to_prevent_from_prefixing {
    /* Input example */
}

.living_classname_to_prevent_from_prefixing {
    /* Input example */
}

.living_classname_to_prevent_from_prefixing .somethingSub {
    /* Input example */
}

Result

.myPrefix .foo {
    /* Output example */
}

.myPrefix .foo, .myPrefix .bar {
    /* Output example */
}

/* not prefixed */
#living_id_prefix_to_prevent_from_prefixing {
    /* Input example */
}

/* not prefixed */
.living_classname_to_prevent_from_prefixing {
    /* Input example */
}

/* not prefixed */
.living_classname_to_prevent_from_prefixing .somethingSub {
    /* Input example */
}

Prefix all but exclude Start-With

// exclude everything which starts with ".grid"
// excludes .grid-x | .grid .mySubClass
postcss([require('prepend-selector-postcss')({
    selector   : '.myPrefix ',
    excludePart: ['.grid']
})])

Original Css

.foo {
    /* Input example */
}

.foo, .bar {
    /* Input example */
}

.grid .padding {
    /* Input example */
}

.grid-x .cell {
    /* Input example */
}

Result

.myPrefix .foo {
    /* Output example */
}

.myPrefix .foo, .myPrefix .bar {
    /* Output example */
}

/* not prefixed */
.grid .padding {
    /* Input example */
}

/* not prefixed */
.grid-x .cell {
    /* Input example */
}

All together

// Full example
postcss([require('prepend-selector-postcss')({
    selector   : '.myPrefix ',
    exclude    : ['#living_id_prefix_to_prevent_from_prefixing ', '.living_classname_to_prevent_from_prefixing '],
    excludePart: ['.grid']
})])

Original Css

.foo {
    /* Input example */
}

.foo, .bar {
    /* Input example */
}

#living_id_prefix_to_prevent_from_prefixing {
    /* Input example */
}

.living_classname_to_prevent_from_prefixing {
    /* Input example */
}

.living_classname_to_prevent_from_prefixing .somethingSub {
    /* Input example */
}

.grid .padding {
    /* Input example */
}

.grid-x .cell {
    /* Input example */
}

Result

.myPrefix .foo {
    /* Output example */
}

.myPrefix .foo, .myPrefix .bar {
    /* Output example */
}

/* not prefixed */
#living_id_prefix_to_prevent_from_prefixing {
    /* Input example */
}

/* not prefixed */
.living_classname_to_prevent_from_prefixing {
    /* Input example */
}

/* not prefixed */
.living_classname_to_prevent_from_prefixing .somethingSub {
    /* Input example */
}

/* not prefixed */
.grid .padding {
    /* Input example */
}

/* not prefixed */
.grid-x .cell {
    /* Input example */
}

Note

Please do not forget "selector" and "exclude" the space at the end of the string. exclude and excludePart are not tested. feel free to fork.

See [PostCSS] docs for examples for your environment.

Forked from

https://github.com/ledniy/postcss-prepend-selector