如何将背景色保存到localStorage？

Question

I have a to-do list that saves to localStorage with a Priority button that changes the background color to red. That color doesn't save on refresh or adding a new to-do item. Is it possible to save color to localStorage? https://jsfiddle.net/kiddigit/hg6w01zn/

function priority() {
  var id = this.getAttribute('value');
  var todos = get_todos();

  localStorage.setItem('todo', JSON.stringify(todos));
  document.getElementById(id).style.background = "red";

  return false;
}

Answer 1

If you want to store a background color with the item, you're going to need to store the item as an object instead of just the name.

I recommend adding logic like this to your add method:

function add() {
    var task = document.getElementById('task').value;
    var todos = get_todos();
    var newTask = {
                name:task, 
                id: "item" + todos.length, 
                priority: {
                            isPriority:false, 
                            color:""
                          }
             };

    todos.push(newTask);
    localStorage.setItem('todo', JSON.stringify(todos));

    show();

    return false;
}

Then, when you show() those, your loop will look like this:

  for (var i = 0; i < todos.length; i++) {
      var todo = todos[i];
      html += "<p id='item" + i + "' isPriority='" + 
      todo.priority.isPriority + "'>" + todo["name"] + '<p>' + 
      "<button class='remove'>Delete</button>" + " " + 
      "<button class='priority' value='item" + i + "'>Priority</button>";
  };

Then when you set the priority on the object, you're just setting the

todos[i].priority.isPriority = true;

and

todos[i].priority.color = "red";

If you want to define your color based on the property, you could just set a property in the html as isPriority=true and then in css do this:

[isPriority="true"] {
    background-color: red;
}

Check out this example: https://jsfiddle.net/1Lgrb7c8/2/