Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

JavaScript

Babel is required to process package imports. If you need a different preprocessor remove all packages first.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <h2>
  The info below will change in <span id='timer'>5</span> seconds</h2>
<div id="input-area">
</div>
<!-- View层 end -->
              
            
!

CSS

              
                table {
  border: 1px solid #ddd;
  border-collapse: collapse;
}
td, th {
  border: 1px solid #ddd;
}
ul, li {
  list-style: none;
}
.school {
  margin-top: 10px;
  padding: 10px;
  border: 1px solid #ddd;
}
.school--yellow {
  border: 1px solid dark-yellow;
  color: #fff;
  background-color: yellow;
}
              
            
!

JS

              
                // --- View层 请看Html代码段
// --------- Model层 ----------
var newPerson = {
  myInput: "dfdf"
};

// --------- viewModel层 ----------
// console.log(window)
var snabbdom = window.snabbdom; //定义patch函数 实现dom节点更新的核心方法
var patch = snabbdom.init([
  snabbdom_class,
  snabbdom_props,
  snabbdom_style,
  snabbdom_eventlisteners
]);
var h = window.h; // 定义h函数
var toVNode = window.tovnode.default; // 定义toVNode函数
var oldVNode = null,
  newVNode = null;
function bindInputModel() {
  var inputEl = document.querySelector("#my-input");
  if (inputEl && inputEl.value !== undefined) {
    inputEl.oninput = function(e) {
      console.log(newPerson.myInput);
      if (e.target.value !== newPerson.myInput) {
        newPerson.myInput = e.target.value;
      }
    };
  }
}
function updateInputArea(newVal, oldVal) {
  var el = document.querySelector("#input-area");
  // 传统的拼接html字符串的方式实现更新视图View
  var compiled = _.template(
    '<input type="text" class="form-control" data-hotkey="xxxhotkey" name="search" value="${ myInput }" placeholder="Search or jump to…" id="my-input" /><span>The value of the input is <b id="my-input__val">${ myInput }</b></span>'
  );
  var inputEl = el.querySelector("#my-input");
  if (!inputEl) {
    el.innerHTML = compiled({ myInput: newVal });
    oldVNode = toVNode(el);
  bindInputModel();
  } else { // 关键的实现双向绑定代码如下
    var newNode = el.cloneNode(false)
    newNode.innerHTML = compiled({ myInput: newVal });
    newVNode = toVNode(newNode)
    patch(oldVNode, newVNode)
    oldVNode = newVNode
  }
}
Object.defineProperty(newPerson, "myInput", {
  set: function(x) {
    if (x !== this.oldPropValue) {
      updateInputArea(x, this.oldPropValue);
      this.oldPropValue = x;
    } else {
      console.log("myInput的值没变");
    }
  },
  get: function() {
    console.log("in property get accessor");
    return this.oldPropValue;
  },
  enumerable: true,
  configurable: true
});
bindInputModel();

// --------- mvvm 数据驱动开发方式,现在只需修改newPerson的数据,View层的Dom节点会自动更新,如下:
setTimeout(function() {
  newPerson.myInput = "新的值";
}, 5000);

// 下面只是计时器,与上面无关,set the timer
Object.prototype.delay = function(time, doSomething) {
  var self = this,
    startTime = time;
  if (self) {
    setTimeout(function() {
      doSomething(self, startTime);
    }, time);
  }
  return this;
};
var el = document.querySelector("#timer");
for (var i = 0; i <= 5; i++) {
  el.delay(i * 1000, function(self, startTime) {
    self.innerHTML = 5 - startTime / 1000;
  });
}

              
            
!
999px

Console