Bootstrap color modes

bt-color-modes.html.twig

<!-- start theme selector -->
<div class="dropdown position-fixed bottom-0 end-0 mb-3 me-3 bd-mode-toggle" id="theme-switcher">
    <button class="btn btn-primary py-2 dropdown-toggle d-flex align-items-center" id="bd-theme" type="button" aria-expanded="false" data-bs-toggle="dropdown" aria-label="Toggle theme (auto)" spellcheck="false">
        <i class="bi bi-lightbulb"></i>
        <span class="visually-hidden" id="bd-theme-text">Choix du thème</span>
    </button>
    <ul class="dropdown-menu dropdown-menu-end shadow" aria-labelledby="bd-theme-text" style="">
        <li>
            <button type="button" class="dropdown-item d-flex align-items-center" data-bs-theme-value="light" aria-pressed="false" spellcheck="false">
                Thème clair
            </button>
        </li>
        <li>
            <button type="button" class="dropdown-item d-flex align-items-center" data-bs-theme-value="dark" aria-pressed="false" spellcheck="false">
                Thème sombre
            </button>
        </li>
        <li>
            <button type="button" class="dropdown-item d-flex align-items-center active" data-bs-theme-value="auto" aria-pressed="true" spellcheck="false">
                Automatique
            </button>
        </li>
    </ul>
</div>
<!-- end theme selector -->

bt-color-modes.js

/*!
 * Color mode toggler for Bootstrap's docs (https://getbootstrap.com/)
 * Copyright 2011-2023 The Bootstrap Authors
 * Licensed under the Creative Commons Attribution 3.0 Unported License.
 */

(() => {
    'use strict'

    const getStoredTheme = () => localStorage.getItem('theme')
    const setStoredTheme = theme => localStorage.setItem('theme', theme)

    const getPreferredTheme = () => {
        const storedTheme = getStoredTheme()
        if (storedTheme) {
            return storedTheme
        }

        return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'
    }

    const setTheme = theme => {
        if (theme === 'auto' && window.matchMedia('(prefers-color-scheme: dark)').matches) {
            document.documentElement.setAttribute('data-bs-theme', 'dark')
        } else {
            document.documentElement.setAttribute('data-bs-theme', theme)
        }
    }

    setTheme(getPreferredTheme())

    const showActiveTheme = (theme, focus = false) => {
        const themeSwitcher = document.querySelector('#bd-theme')

        if (!themeSwitcher) {
            return
        }

        const themeSwitcherText = document.querySelector('#bd-theme-text')
        const activeThemeIcon = document.querySelector('.theme-icon-active use')
        const btnToActive = document.querySelector(`[data-bs-theme-value="${theme}"]`)

        document.querySelectorAll('[data-bs-theme-value]').forEach(element => {
            element.classList.remove('active')
            element.setAttribute('aria-pressed', 'false')
        })

        btnToActive.classList.add('active')
        btnToActive.setAttribute('aria-pressed', 'true')
        const themeSwitcherLabel = `${themeSwitcherText.textContent} (${btnToActive.dataset.bsThemeValue})`
        themeSwitcher.setAttribute('aria-label', themeSwitcherLabel)

        if (focus) {
            themeSwitcher.focus()
        }
    }

    window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', () => {
        const storedTheme = getStoredTheme()
        if (storedTheme !== 'light' && storedTheme !== 'dark') {
            setTheme(getPreferredTheme())
        }
    })

    window.addEventListener('DOMContentLoaded', () => {
        showActiveTheme(getPreferredTheme())

        document.querySelectorAll('[data-bs-theme-value]')
            .forEach(toggle => {
                toggle.addEventListener('click', () => {
                    const theme = toggle.getAttribute('data-bs-theme-value')
                    setStoredTheme(theme)
                    setTheme(theme)
                    showActiveTheme(theme, true)
                })
            })
    })
})()