Using native JS and jQuery to realize digital linear change animation

Preface

Everyone should have some experience. In the special pages of some data display, it is sometimes hoped that the number can dynamically change from one number to another, so as to attract users' attention and highlight the data. So there is the following.

Here, I use two methods: one is the native JavaScript, and the other is the jQuery plug-in.

The principle of linear change of numbers is very simple, that is, let numbers change incrementally and circulate animation.

Native JS version

First, get the DOM element. In order to be compatible with IE6, the compatibility methods are as follows:

var domUtil = {
 //  Get DOM Element 
 get: function(query) {
  var _this = this;
  if(document.querySelector) {
   return document.querySelector(query);
  } else {
   var elements = document;
   var queryStrArray = query.split(/ +/);
   for(var i = 0; i < queryStrArray.length; i++) {
    var domName = queryStrArray[i];
    elements = _this.getElementsOfParentNode(domName, elements);
   }
   if(elements.length == 1) {
    return elements[0];
   } else {
    return elements;
   }
  }
 },
 //  Get DOM Element 
 getElementsOfParentNode: function(domName, parentNode) {
  var _this = this;
  parentNode = parentNode || document;
  domName = domName.trim();
  var regExps = {
   id: /^#/,
   class: /^/
  };
  if(regExps.id.test(domName)) {
   domName = domName.replace(/^\#/g, "");
   return parentNode.getElementById(domName);
  } else if(regExps.class.test(domName)) {
   domName = domName.replace(/^./g, "");
   return _this.getElementsByClassName(domName, parentNode);
  } else {
   return parentNode.getElementsByTagName(domName);
  }
 },
 //  Get class Compatible method of element 
 getElementsByClassName: function(className, parentNode) {
  if(parentNode.getElementsByClassName){
   return parentNode.getElementsByClassName(className);
  } else {
   className = className.replace(/^ +| +$/g,"");
   var classArray = className.split(/ +/);
   var eles = parentNode.getElementsByTagName("*");
   for(var i = 0;i < classArray.length; i++){
    var classEles = [];
    var reg = new RegExp("(^| )" + classArray[i] + "( |$)");
    for(var j = 0;j < eles.length; j++){
     var ele = eles[j];
     if(reg.test(ele.className)){
      classEles.push(ele);
     }
    }
    eles = classEles;
   }
   return eles;
  }
 }
};

/*
 *  Digital animation (currently only linear changes of digital animation are supported) 
 * options Parameters: 
 *  element {String} DOM Element query String 
 *  from {Number}  Starting number 
 *  to {Number}  End number 
 *  duration {Number}  Animation time 
 *  callback {Function}  Callback function when numbers change 
 */
var animatingNumber = function(options) {
 this.element = domUtil.get(options.element);
 this.startNum = options.from;
 this.endNum = options.to;
 this.duration = options.duration || 2000;
 this.callback = options.callback;

 this.timer = null;
};

animatingNumber.prototype = {
 start: function() {
  var _this = this;
  _this.animate();
 },
 stop: function() {
  if(this.timer) {
   clearTimeout(this.timer);
   this.timer = null;
  }
 },
 animate: function() {
  var _this = this;
  var curNum = _this.startNum;
  var animateTime = 0;
  var range = _this.endNum - _this.startNum;
  var timerStep = Math.abs( Math.floor(_this.duration / range) );
  timerStep = timerStep > 20 ? timerStep : 20;
  var numStep = (range / _this.duration) * timerStep;

  _this.stop();

  (function animate() {
   _this.timer = setTimeout(function() {
    curNum = Math.ceil( curNum + numStep );
    if( (_this.endNum > _this.startNum && curNum >= _this.endNum) || (_this.endNum < _this.startNum && curNum <= _this.endNum) ) {
     curNum = _this.endNum;
    }
    _this.element.innerText = curNum;
    animateTime++;
    if(typeof this.callback == 'function') {
     this.callback(curNum);
    }
    animate();
    if(curNum >= _this.endNum) {
     _this.stop();
    }
   }, timerStep);
  })();
 }
};

animatingNumber.create = function(options) {
 return new animatingNumber(options);
};

Use:

<p>Number: <span class='dynamicNum'>500</span></p>

<script>
 animatingNumber.create({
  element: '.dynamicNum',
  from: 1,
  to: 500,
  duration: 2000
 }).start();
</script>

jQuery Plug-in Edition

The principle is the same as above, except that DOM element acquisition uses jQuery method, and the digital animation method is encapsulated into jQuery plug-in.

As follows:

/*
 *  Digital animation (currently only linear changes of digital animation are supported) 
 * options Parameters: 
 *  from {Number}  Starting number 
 *  to {Number}  End number 
 *  duration {Number}  Animation time 
 *  callback {Function}  Callback function when numbers change 
 */
(function( $ ) {
 $.fn.animatingNumber = function(options) {
  var settings = {
   element: this,
   startNum: options.from,
   endNum: options.to,
   duration: options.duration || 2000,
   callback: options.callback
  };
  var timer = null;

  var methods = {
   start: function() {
    var _this = this;
    _this.animate();
   },
   stop: function() {
    if(timer) {
     clearTimeout(timer);
     timer = null;
    }
   },
   animate: function() {
    var _this = this;
    var curNum = settings.startNum;
    var animateTime = 0;
    var range = settings.endNum - settings.startNum;
    var timerStep = Math.abs( Math.floor(settings.duration / range) );
    timerStep = timerStep > 20 ? timerStep : 20;
    var numStep = (range / settings.duration) * timerStep;

    _this.stop();

    (function animate() {
     timer = setTimeout(function() {
      curNum = Math.ceil( curNum + numStep );
      if( (settings.endNum > settings.startNum && curNum >= settings.endNum) || (settings.endNum < settings.startNum && curNum <= settings.endNum) ) {
       curNum = settings.endNum;
      }
      settings.element.text(curNum);
      animateTime++;
      if(typeof settings.callback == 'function') {
       settings.callback(curNum);
      }
      animate();
      if(curNum >= settings.endNum) {
       _this.stop();
      }
     }, timerStep);
    })();
   }
  };
  return this.each(function() {
   return methods.start();
  });

 };
})( jQuery );

Use:

<p>Number: <span class='dynamicNum'></span></p>

<script>
$('.dynamicNum').animatingNumber({
 from: 1,
 to: 1000,
 duration: 2000
});
</script>

Finally

Ok, that's all the content of this article, and we will consider adding the option of slow-moving function later. I hope the content of this article can bring 1 certain help to your study or work. If you have any questions, you can leave a message for communication.