Common methods about js registration events_javascript skills

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;(function(){
//Library encapsulation to prevent object pollution
window['cm']={};
/**
*Register events for objects
*/
var addListener=function(element,type,fn){
if(typeof element == 'undefined') return false;
if(element.addEventListener){
element.addEventListener(type,fn, false);
}else if(element.attachEvent){
var _EventRef='_' type 'EventRef';
                                                                                                              _EventRefs=element[_EventRef];
var index;
for(index in _EventRefs){
if(_EventRefs[index]['realFn']==fn){
return;
                                                                                                                                                                                                                                                var nestFn=function(){
                  fn.apply(element,arguments); 🎜>           element.attachEvent('on' type, nestFn); ]['addListener']=addListener;
/**
*Remove registered events on the object
*/
var removeListener=function(element,type,fn){
if(typeof element == 'undefined') return false ;
if(element.removeEventListener){
element.removeEventListener(type,fn,false);
}else if(element.detachEvent){
var _EventRef='_' 'EventRef' ;
                                                                                                                                                                                                            🎜> var index;
var nestFn;
for(index in _EventRefs){
if(_EventRefs[index]['realFn']==fn){
nestFn=_EventRefs[index]['nestFn'];
if(index ==_EventRefs.length-1){
                                                                                                                                                           else{
                        element[_EventRef]=_EventRefs.slice(0,index).concat(_EventRefs.slice(index 1,_EventRefs.length-1));
                    }
                    break;
                }
            }
            if(nestFn){
                element.detachEvent('on' type,nestFn);
            }
        }else{
            element['on' type]=null;
        }
    };
})();