Flowbite暗模式问题

Question

我正试图在我的应用程序中实现Flowbite暗模式，但遇到了一些奇怪的问题。我遵循了docs-url，并在控制台中收到了这个错误：

Uncaught TypeError: Cannot read properties of null (reading 'classList')

据我所知，它说一个或多个值(themeTogleDarkIcon或themeToggleLightIcon(为null或基本上没有定义。基本上，我到目前为止所做的-创建了一个组件-ThemeSwitcher.vue，内容为：

<template>
<button id="theme-toggle" type="button"
class="text-gray-500 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-gray-700 focus:outline-none focus:ring-4 focus:ring-gray-200 dark:focus:ring-gray-700 rounded-lg text-sm p-2.5">
<svg id="theme-toggle-dark-icon" class="hidden w-5 h-5" fill="currentColor" viewBox="0 0 20 20"
xmlns="http://www.w3.org/2000/svg">
<path d="M17.293 13.293A8 8 0 016.707 2.707a8.001 8.001 0 1010.586 10.586z"></path>
</svg>
<svg id="theme-toggle-light-icon" class="hidden w-5 h-5" fill="currentColor" viewBox="0 0 20 20"
xmlns="http://www.w3.org/2000/svg">
<path
d="M10 2a1 1 0 011 1v1a1 1 0 11-2 0V3a1 1 0 011-1zm4 8a4 4 0 11-8 0 4 4 0 018 0zm-.464 4.95l.707.707a1 1 0 001.414-1.414l-.707-.707a1 1 0 00-1.414 1.414zm2.12-10.607a1 1 0 010 1.414l-.706.707a1 1 0 11-1.414-1.414l.707-.707a1 1 0 011.414 0zM17 11a1 1 0 100-2h-1a1 1 0 100 2h1zm-7 4a1 1 0 011 1v1a1 1 0 11-2 0v-1a1 1 0 011-1zM5.05 6.464A1 1 0 106.465 5.05l-.708-.707a1 1 0 00-1.414 1.414l.707.707zm1.414 8.486l-.707.707a1 1 0 01-1.414-1.414l.707-.707a1 1 0 011.414 1.414zM4 11a1 1 0 100-2H3a1 1 0 000 2h1z"
fill-rule="evenodd" clip-rule="evenodd"></path>
</svg>
</button>
</template>
<script>
var themeToggleDarkIcon = document.getElementById('theme-toggle-dark-icon');
var themeToggleLightIcon = document.getElementById('theme-toggle-light-icon');
// Change the icons inside the button based on previous settings
if (localStorage.getItem('color-theme') === 'dark' || (!('color-theme' in localStorage) && window.matchMedia('(prefers-color-scheme: dark)').matches)) {
themeToggleLightIcon.classList.remove('hidden');
} else {
themeToggleDarkIcon.classList.remove('hidden');
}
var themeToggleBtn = document.getElementById('theme-toggle');
themeToggleBtn.addEventListener('click', function () {
// toggle icons inside button
themeToggleDarkIcon.classList.toggle('hidden');
themeToggleLightIcon.classList.toggle('hidden');
// if set via local storage previously
if (localStorage.getItem('color-theme')) {
if (localStorage.getItem('color-theme') === 'light') {
document.documentElement.classList.add('dark');
localStorage.setItem('color-theme', 'dark');
} else {
document.documentElement.classList.remove('dark');
localStorage.setItem('color-theme', 'light');
}
// if NOT set via local storage previously
} else {
if (document.documentElement.classList.contains('dark')) {
document.documentElement.classList.remove('dark');
localStorage.setItem('color-theme', 'light');
} else {
document.documentElement.classList.add('dark');
localStorage.setItem('color-theme', 'dark');
}
}
});
</script>

将代码导入其他组件并实现：

<template>
<section>
<ThemeSwitcher />
</section>
</template>
<script>
import ThemeSwitcher from "../../components/ThemeSwitcher.vue";
export default {
name: "Login",
components: {
ThemeSwitcher
}
}
</script>

似乎所有的事情都像文档中一样完成，但错误是凭空发生的！

Answer 1

该错误是因为在初始化文档之前访问classList

我的组件解决问题

<script setup>
import {onMounted, ref} from "vue";
const themeToggleDarkIcon = ref(null);
const themeToggleLightIcon = ref(null);
const setDarkTheme = () => {
document.documentElement.classList.add('dark');
localStorage.setItem('color-theme', 'dark');
themeToggleLightIcon.value.classList.remove('hidden');
themeToggleDarkIcon.value.classList.add('hidden');
}
const setLightTheme = () => {
document.documentElement.classList.remove('dark');
localStorage.setItem('color-theme', 'light');
themeToggleLightIcon.value.classList.add('hidden');
themeToggleDarkIcon.value.classList.remove('hidden');
}
const toggleTheme = () => {
// toggle icons inside button
themeToggleDarkIcon.value.classList.toggle('hidden');
themeToggleLightIcon.value.classList.toggle('hidden');
// if set via local storage previously
if (localStorage.getItem('color-theme')) {
if (localStorage.getItem('color-theme') === 'dark') {
setLightTheme();
} else {
setDarkTheme();
}
// if NOT set via local storage previously
} else {
if (document.documentElement.classList.contains('dark')) {
setLightTheme();
} else {
setDarkTheme();
}
}
}
const initializeTheme = () => {
const isDarkFromLocalStorage = localStorage.getItem('color-theme') === 'dark';
const mySystemPreferenceIs = window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
// Change the icons inside the button based on previous settings
if (isDarkFromLocalStorage || (!('color-theme' in localStorage) && mySystemPreferenceIs === 'dark')) {
setDarkTheme();
} else {
setLightTheme();
}
}
onMounted(() => {
initializeTheme();
})
</script>
<template>
<button
id="theme-toggle"
class="text-gray-500 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-gray-700 focus:outline-none focus:ring-4 focus:ring-gray-200 dark:focus:ring-gray-700 rounded-lg text-sm p-2.5"
type="button"
@click="toggleTheme"
>
<svg
id="theme-toggle-dark-icon"
ref="themeToggleDarkIcon"
class="hidden w-5 h-5"
fill="currentColor"
viewBox="0 0 20 20"
xmlns="http://www.w3.org/2000/svg"
>
<path d="M17.293 13.293A8 8 0 016.707 2.707a8.001 8.001 0 1010.586 10.586z" />
</svg>
<svg
id="theme-toggle-light-icon"
ref="themeToggleLightIcon"
class="hidden w-5 h-5"
fill="currentColor"
viewBox="0 0 20 20"
xmlns="http://www.w3.org/2000/svg"
>
<path
clip-rule="evenodd"
d="M10 2a1 1 0 011 1v1a1 1 0 11-2 0V3a1 1 0 011-1zm4 8a4 4 0 11-8 0 4 4 0 018 0zm-.464 4.95l.707.707a1 1 0 001.414-1.414l-.707-.707a1 1 0 00-1.414 1.414zm2.12-10.607a1 1 0 010 1.414l-.706.707a1 1 0 11-1.414-1.414l.707-.707a1 1 0 011.414 0zM17 11a1 1 0 100-2h-1a1 1 0 100 2h1zm-7 4a1 1 0 011 1v1a1 1 0 11-2 0v-1a1 1 0 011-1zM5.05 6.464A1 1 0 106.465 5.05l-.708-.707a1 1 0 00-1.414 1.414l.707.707zm1.414 8.486l-.707.707a1 1 0 01-1.414-1.414l.707-.707a1 1 0 011.414 1.414zM4 11a1 1 0 100-2H3a1 1 0 000 2h1z"
fill-rule="evenodd"
/>
</svg>
</button>
</template>