Snippet Zone

Multiple Class Trick

```
.thing.thing.thing {
```
```
  color: green;
```
```
}
```
```
 
```
```
.thing.thing {
```
```
  color: red;
```
```
}
```
```
 
```
```
.thing {
```
```
  color: blue;
```
```
}
```

What color would p.thing be?

March 19, 2022

// css // tricks // ui

Todo MVC (not mvc)

```
<!DOCTYPE html>
```
```
<html lang="en">
```
```
  <head>
```
```
    <meta charset="utf-8" />
```
```
    <title></title>
```
```
    <style>
```
```
      body {
```
```
        background: white;  
```
```
      }
```
```
      .new-todo {
```
```
        padding: 4px;
```
```
      }
```
```
      .todo {
```
```
        border: 1px solid black;
```
```
        overflow: hidden;
```
```
        background: #efefef;
```
```
      }
```
```
      .todo-close {
```
```
        display: none;
```
```
      }
```
```
      .todo:hover .todo-close {
```
```
        display: block;
```
```
      }
```
```
      .todo * {
```
```
        float: left;
```
```
        padding: 10px; 
```
```
      }
```
```
      .todo-complete {
```
```
        background: green;
```
```
      }
```
```
      .todo-complete .todo-val {
```
```
        text-decoration: line-through;
```
```
        color: white;
```
```
      }
```
```
 
```
```
      .show-active .todo-complete {
```
```
        display: none;
```
```
      }
```
```
 
```

      .show-complete .todo:not(.todo-complete) {

```
        display: none;
```
```
      }
```
```
      .todo-edit {
```
```
        background: gray !important;
```
```
        color: black !important;
```

        text-decoration: none !important;

```
      }
```
```
      .todo-name {
```
```
        width: 200px;  
```
```
        border: 1px solid gray;
```
```
      }
```
```
 
```
```
      .check-all[data-on="true"] {
```
```
        font-weight: bold;
```
```
 
```
```
        background: darkGray;
```
```
      }
```
```
    </style>
```
```
  </head>
```
```
  <body>
```
```
    <div class="app">
```

      <button class="check-all">&#9660;</button>

      <input class="todo-name" type="text" placeholder="What needs to be done?"/>

```
      <div class="todos"></div>
```
```
      <div class="todo-foot">
```
```
        <span>
```

          <span class="todo-num">#</span>

          item<span class="plural">s</span>

```
          left
```
```
        </span>
```

        <button class="all">all</button>

        <button class="active">active</button>

        <button class="completed">completed</button>

        <button class="clear-completed">clear completed</button>

```
      </div>
```
```
    </div>
```
```
 
```
```
    <script id="todo" type="text/html">
```
```
      <div class="todo">
```

        <input class="todo-check" type="checkbox" />

        <div class="todo-val">$val</div>

        <button class="todo-close">X</button>

```
      </div>
```
```
    </script> 
```
```
 
```
```
    <script>
```
```
      (function() {  
```

        var todoName = document.querySelector('.todo-name'),

            todoTmpl = document.querySelector('#todo').innerHTML,

            todos = document.querySelector('.todos'),

            todoFoot = document.querySelector('.todo-foot'),

            todoNum = document.querySelector('.todo-num'),

            plural = document.querySelector('.plural'),

            checkAll = document.querySelector('.check-all'),

```
            evts = {};
```
```
 
```
```
        function save() {
```

          localStorage.todos = todos.innerHTML;

```
        }
```
```
 
```
```
        function addTodo(value) {
```

          if (value.trim().length > 0) {

```
            todoName.value = '';
```

            todos.innerHTML += todoTmpl.replace('$val', value);

```
            generalUpdate();
```
```
          }
```
```
        }
```
```
 
```

        function updateProp(target, attr, val) {

          val ? target.setAttribute(attr, attr) : target.removeAttribute(attr);

```
          target[attr] = val;
```
```
        }
```
```
 
```

        function setTodoComplete(todo, val) {

```
          if (val) {
```

            todo.classList.add('todo-complete');

```
          } else {
```

            todo.classList.remove('todo-complete');

            checkAll.setAttribute('data-on', false);

            localStorage.setItem('allChecked', false);

```
          }
```

          updateProp(todo.querySelector('.todo-check'), 'checked', val);

```
        }
```
```
 
```

        function updateItemsLeft(todoCount) {

          todoNum.innerHTML = todoCount;

          plural.style.display = todoCount === 1 ? 'none' : 'inline';

```
        }
```
```
 
```

        function handleNoItems(todoCount) {

          todoFoot.style.display = todoCount === 0 ? 'none' : 'block';

```
        }
```
```
 
```
```
        function generalUpdate() {
```

          var todoCount = document.querySelectorAll('.todo').length,

              todoCompleted = document.querySelectorAll('.todo-complete');

          updateItemsLeft(todoCount - todoCompleted.length);

```
          handleNoItems(todoCount);
```
```
          save();
```
```
        }
```
```
 
```

        evts['check-all-click'] = function() {

          var todos = document.querySelectorAll('.todo'),

```
              leng = todos.length,
```

              val = checkAll.allChecked = !checkAll.allChecked;

          for (var i = 0; i < leng; i++) {

            setTodoComplete(todos[i], val);

```
          }
```

          checkAll.setAttribute('data-on', val);

          localStorage.setItem('allChecked', val);

```
        };
```
```
 
```

        evts['todo-close-click'] = function(e, todo) {

```
          todos.removeChild(todo);
```
```
        };
```
```
 
```

        evts['todo-check-click'] = function(e, todo) {

          setTodoComplete(todo, e.target.checked);

```
        };
```
```
 
```

        evts['all-click'] = function() {

          todos.classList.remove('show-active');

          todos.classList.remove('show-complete');

```
          delete localStorage.mode;
```
```
        };
```
```
 
```

        evts['active-click'] = function() {

```
          evts['all-click']();
```

          todos.classList.add('show-active');

```
          localStorage.mode = 'active';
```
```
        };
```
```
 
```

        evts['completed-click'] = function() {

```
          evts['all-click']();
```

          todos.classList.add('show-complete');

          localStorage.mode = 'completed';

```
        };
```
```
 
```

        evts['clear-completed-click'] = function(e, todo) {

          var completed = document.querySelectorAll('.todo-complete'),

```
              leng = completed.length;
```

          for (var i = 0; i < leng; i++) {

            completed[i].parentNode.removeChild(completed[i]);

```
          }
```
```
        };
```
```
 
```

        todoName.addEventListener('change', function(e) {

```
          addTodo(todoName.value);
```
```
        });
```
```
 
```

        document.addEventListener('click', function(e) {

          var key = e.target.className + '-click',

              todo = e.target.parentNode;

```
          if (evts[key] != null) {
```
```
            evts[key](e, todo);
```
```
            generalUpdate();
```
```
          }
```
```
        });
```
```
 
```
```
        function todoBlur(e) {
```

          e.target.removeEventListener('blur', todoBlur);

          e.target.classList.remove('todo-edit');

          e.target.contentEditable = false;

          if (e.target.innerHTML.trim().length === 0) {

            e.target.parentNode.parentNode.removeChild(e.target.parentNode);

```
          }
```
```
          save();
```
```
        }
```
```
 
```

        document.addEventListener('dblclick', function(e) {

```
          var range, sel;
```

          if (e.target.className === 'todo-val') {

            e.target.contentEditable = true;

            e.target.initialVal = e.target.innerHTML;

```
            e.target.focus();
```

            e.target.addEventListener('blur', todoBlur);

            e.target.classList.add('todo-edit');

```
 
```
```
            // put cursor at end
```

            range = document.createRange();

            range.selectNodeContents(e.target);

```
            range.collapse(false);
```

            sel = window.getSelection();

```
            sel.removeAllRanges();
```
```
            sel.addRange(range);
```
```
          }
```
```
        });
```
```
 
```

        document.addEventListener('keydown', function(e) {

          if (document.activeElement.classList.contains('todo-val')) {

            if (e.which === 27) { // ESC

              e.target.innerHTML = e.target.initialVal;

```
              todoBlur(e);  
```

            } else if (e.which === 13) { // ENTER

```
              todoBlur(e);  
```
```
            }
```
```
          }
```
```
        });
```
```
 
```

        document.addEventListener('keyup', function(e) {

          if (document.activeElement.classList.contains('todo-val')) {

```
            save();
```
```
          }
```
```
        });
```
```
 
```

        if (localStorage.todos != null) todos.innerHTML = localStorage.todos;

        if (localStorage.allChecked === 'true') evts['check-all-click']();

        if (localStorage.mode != null) evts[localStorage.mode + '-click']();

```
 
```
```
        generalUpdate();
```
```
 
```
```
      })();
```
```
    </script>
```
```
  </body>
```
```
</html>
```

I’ve always liked Todo MVC. At some point a few years back I tried to re-create the behavior in a natural vanilla way (whatever was natural to me). The above is what came out at the time. Now, with es6 and some other tricks that I like to use – I think this could be even better… still fun to look at.

NOTE: It is not MVC at all – not even close 😀

March 18, 2022

// javascript // tricks // ui

Proxy Constants

```
const spec = {
```
```
  get(o, key) { 
```
```
    return o[key] != null ? 
```
```
      o[key] : o[key] = Objector()
```
```
  }
```
```
};
```
```
 
```

const Objector = () => new Proxy({}, spec);

```
 
```
```
const events = Objector();
```
```
 
```
```
events.graphics.RENDERED;
```
```
events.graphics.ERASED;
```
```
events.ui.LOADING;
```
```
events.ui.LOADED;
```
```
events.files.OPENED;
```
```
events.files.CLOSED;
```
```
 
```
```
const { ERASED } = events.graphics;
```

console.log('a', ERASED === events.graphics.ERASED);

console.log('b', ERASED === events.files.CLOSED);

This is somewhat evil… I’ve never liked these java style constants. Maybe I’ll write up a detailed alternative method some time.

March 8, 2022

// humor // proxies // tricks

What is Clicked?

document.addEventListener('click', e => console.log(e.target))

Try that one in your console and then click on stuff. I use that frequently when debugging…

March 3, 2022

// dom // tricks // ui

Cut Hole in Canvas (eraser)

document.body.style.background = 'gray';

const canvas = document.createElement('canvas');

```
const c = canvas.getContext('2d');
```
```
 
```
```
canvas.width = 300;
```
```
canvas.height = 300;
```
```
 
```
```
c.fillStyle='rgba(255, 0, 0, 0.8)'
```

c.fillRect(0, 0, canvas.width, canvas.height);

```
 
```

c.globalCompositeOperation = 'destination-out';

```
c.fillStyle = 'black';
```
```
c.fillRect(100, 100, 150, 50);
```
```
 
```
```
document.body.appendChild(canvas);
```

destination-out is great for creating masks and eraser tools – things like that – in this case a 150×50 rectangle is cut out of a red background.

March 2, 2022

// canvas // color // graphics // tricks

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