Day/Night Toggle Using Cookie to Save on Page Refresh

问题

The problem I'm having of course is the toggle cookie is always true once the toggle is clicked. Is there a way to check whether the toggle is active / inactive and to save that state to a cookie to then check on page refresh if dark mode should be activated?

jQuery(document).ready(function($) {
  $(".toggle").click(function() {
    $(".toggle").toggleClass("active");
    $("body").toggleClass("night");
    $.cookie("toggle", true);
  });

  if ($.cookie("toggle") == "true") {
    $(".toggle").click();
  }
});

body.night {
  background: #00151f;
  color: #fff;
}

.toggle {
  position: absolute;
  top: 40px;
  left: 0px;
  background: #fff;
  border: 2px solid #00151f;
  width: 45px;
  height: 20px;
  cursor: pointer;
  border-radius: 20px;
  transition: 0.5s;
}

.toggle.active {
  background: #00151f;
  border: 1px solid #fff;
}

.toggle:before {
  left: 0px;
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  background: #00151f;
  border-radius: 50%;
  transition: 0.5s;
}

.toggle.active:before {
  left: 27px;
  background: #fff;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="toggle"></div>

回答1:

The issue is because you only ever set the cookie to true, even when changing the state. To fix this use hasClass() to determine what state the UI is in and set the cookie accordingly:

jQuery(document).ready(function($) {
  $(".toggle").click(function() {
    $(".toggle").toggleClass("active");
    $("body").toggleClass("night");
    $.cookie("toggle", $(".toggle").hasClass('active'));
  });

  if ($.cookie("toggle") === "true") {
    $(".toggle").addClass("active");
    $("body").addClass("night");
  }
});

Example fiddle

来源：https://stackoverflow.com/questions/54326422/day-night-toggle-using-cookie-to-save-on-page-refresh