javascripthtmlastrojsview-transitions-api

Using viewtransition for dark mode in astro


I am trying to implement the new viewtransition, in my project in astro, the problem is I have found documentation on how to fix the dark mode issue when chaging routes, but I am using a little different code and because of that it does not work, my code:

  // Get the theme toggle input
  const themeToggle: HTMLInputElement = document.querySelector(
    '.theme-switch input[type="checkbox"]'
  );

  // Get the current theme from local storage
  const currentTheme = localStorage.getItem("theme");

  // If the current local storage item can be found
  if (currentTheme) {
    // Set the body data-theme attribute to match the local storage item
    document.documentElement.setAttribute("data-theme", currentTheme);

    // If the current theme is dark, check the theme toggle
    if (currentTheme === "dark") {
      themeToggle.checked = true;
    }
  }

  // Function that will switch the theme based on the if the theme toggle is checked or not
  function switchTheme(e) {
    if (e.target.checked) {
      document.documentElement.setAttribute("data-theme", "dark");
      localStorage.setItem("theme", "dark");
    } else {
      document.documentElement.setAttribute("data-theme", "default");
      localStorage.setItem("theme", "default");
    }
  }

  // Add an event listener to the theme toggle, which will switch the theme
  themeToggle.addEventListener("change", switchTheme, false);
  document.addEventListener("astro:after-swap", switchTheme, false);
  /* TOGGLE  */
  .theme-switch-wrapper {
    margin-inline: 20px;
    display: inline-block;
    /* justify-content: flex-end; */
    /* align-items: center; */
  }

  .theme-switch {
    display: inline-block;
    height: 34px;
    position: relative;
    width: 60px;
  }

  .theme-switch input {
    display: none;
  }

  .slider {
    background-color: #dddddd;
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: 0.4s;
    border-radius: 34px;
  }

  .slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: 0.4s;
    width: 26px;
    border-radius: 50%;
  }

  input:checked + .slider {
    background-color: #8758ff;
  }

  input:checked + .slider:before {
    transform: translateX(26px);
  }

  .slider svg {
    color: #222;
    position: absolute;
    transition: opacity 0.2s ease 0s, transform 0.35s ease 0s;
    pointer-events: none;
  }

  .feather-moon {
    opacity: 0;
    left: 9px;
    bottom: 9px;
    transform: translateX(4px);
  }

  .feather-sun {
    opacity: 1;
    right: 10px;
    bottom: 9px;
    transform: translateX(0px);
  }

  input:checked + .slider .feather-moon {
    opacity: 1;
    transform: translateX(0);
  }

  input:checked + .slider .feather-sun {
    opacity: 0;
    transform: translateX(-4px);
  }
<div class="theme-switch-wrapper py-2 mt-1">
  <label class="theme-switch" for="checkbox">
    <input type="checkbox" id="checkbox" />
    <div class="slider">
      <svg
        xmlns="http://www.w3.org/2000/svg"
        width="16"
        height="16"
        viewBox="0 0 24 24"
        fill="#FCD53F"
        stroke="currentColor"
        stroke-width="2"
        stroke-linecap="round"
        stroke-linejoin="round"
        class="feather feather-sun"
      >
        <circle cx="12" cy="12" r="5"></circle>
        <line x1="12" y1="1" x2="12" y2="3"></line>
        <line x1="12" y1="21" x2="12" y2="23"></line>
        <line x1="4.22" y1="4.22" x2="5.64" y2="5.64"></line>
        <line x1="18.36" y1="18.36" x2="19.78" y2="19.78"></line>
        <line x1="1" y1="12" x2="3" y2="12"></line>
        <line x1="21" y1="12" x2="23" y2="12"></line>
        <line x1="4.22" y1="19.78" x2="5.64" y2="18.36"></line>
        <line x1="18.36" y1="5.64" x2="19.78" y2="4.22"></line>
      </svg>
      <svg
        xmlns="http://www.w3.org/2000/svg"
        width="16"
        height="16"
        viewBox="0 0 24 24"
        fill="#FCD53F"
        stroke="currentColor"
        stroke-width="2"
        stroke-linecap="round"
        stroke-linejoin="round"
        class="feather feather-moon"
      >
        <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z"></path>
      </svg>
    </div>
  </label>
</div>

So the Problem is I am using a checkbox for the project and most of the projects I've seen that use darkmode with viewtransitions, they use buttons, but my problem I think is that as I am using the change method of the checkbox, and the function I am using, it is made for used when the checkbox changes state, but to make the dark mode button persistent I have to use this EventListener:

  document.addEventListener("astro:after-swap", switchTheme, false);

and because it is not triggered by the checkbox that is why it does not work, those are my thoughts but I don't know how to fix it so please help me.

the real problem is that the button works but when I change routes it goes to default theme, but the checkbox is still on, so the localstorage that is supposed to be persistent, it is not


Solution

  • I've already fixed the issue, here is the code:

      // Get the theme toggle input
      const themeToggle: HTMLInputElement = document.querySelector(
        '.theme-switch input[type="checkbox"]'
      );
    
      // Get the current theme from local storage
      const currentTheme = localStorage.getItem("theme");
    
      // If the current local storage item can be found
      if (currentTheme) {
        // Set the body data-theme attribute to match the local storage item
        document.documentElement.setAttribute("data-theme", currentTheme);
    
        // If the current theme is dark, check the theme toggle
        if (currentTheme === "dark") {
          themeToggle.checked = true;
        }
      }
    
      function switchTheme() {
        if (themeToggle.checked) {
          document.documentElement.setAttribute("data-theme", "dark");
          localStorage.setItem("theme", "dark");
        } else {
          document.documentElement.setAttribute("data-theme", "default");
          localStorage.setItem("theme", "default");
        }
      }
    
      // Add an event listener to the theme toggle, which will switch the theme
      themeToggle.addEventListener("change", switchTheme, false);
      document.addEventListener("astro:after-swap", switchTheme);
    

    I fixed it by changing the switchTheme function so that it checks for the themeToggle variable, instead of the event fired by the eventlistener, that way now it works for the astro after swap eventlistener