code: function(page, data) {
  			if (page.flagAniBind == true) return;
  			// do callback when animation start/end
  			["animationstart", "animationend"].forEach(function(animationkey, index) {
  				var animition = paramsIn[animationkey], webkitkey = "webkit" + animationkey.replace(/^a|s|e/g, function(matchs) {
  					return matchs.toUpperCase();
  				});
  				var animateEventName = isWebkit? webkitkey: animationkey;
  				// if it's the out element, hide it when 'animationend'
  				if (index) {
  					page.addEventListener(animateEventName, function() {
  						if (this.classList.contains("in") == false) {
  							this.style.display = "none";
  							// add on v2.5.5
  							// move here on v2.5.8
  							// main for remove page is just current page
  							// remove on v2.7.0
  							// if (this.removeSelf == true) {
  							// 	this.parentElement.removeChild(this);
  							// 	this.removeSelf = null;
  							// }
  						}
  						this.classList.remove(params(this).form);
  					});
  				}
  				// bind animation events
  				if (typeof animition == "string" && paramsIn.root[animition]) {
  					page.addEventListener(animateEventName, function() {
  						data.root[animition].call(data.root, this, this.classList.contains("in")? "into": "out", options);
  					});
  				} else if (typeof animition == "function") {
  					page.addEventListener(animateEventName, function() {
  						animition.call(data.root, this, this.classList.contains("in")? "into": "out", options);
  					});
  				}
  				// set a flag
  				page.flagAniBind = true;
  			});
  		}
docs: set animation callback as a method