js代码收藏

js对象转换成jquery对象:

 

jQuery(document).ready(function(){
  var links = jQuery("#simple-menu li a");
  for(var i=0;i<links.length;i++){
    jQuery(links[i]).click(function(){
	jQuery(".current").removeClass("current");
        jQuery(this).addClass("current");//将js对象包装成jQuery对象
	 //这里this换成links[i],不会增加current类
     });
   }
  
});

 

动态创建form:

<a href="/topics/1" onclick="if (confirm('你确定要删除这篇博客？')) { var f = document.createElement('form'); f.style.display = 'none'; this.parentNode.appendChild(f); f.method = 'POST'; f.action = this.href;var m = document.createElement('input'); m.setAttribute('type', 'hidden'); m.setAttribute('name', '_method'); m.setAttribute('value', 'delete'); f.appendChild(m);var s = document.createElement('input'); s.setAttribute('type', 'hidden'); s.setAttribute('name', 'authenticity_token'); s.setAttribute('value', '4k3y+j4gi85qFk7QQugsdEuWiCoOFrLPPLJgye7ERXg='); f.appendChild(s);f.submit(); };return false;">删除</a> 

 

 

Handling runtime errors in JavaScript using try/catch/finally

alert("I am missing a closing parenthesis //syntax error
alert(x) //exception assuming "x" isn't defined yet
undefinedfunction() //exception

 

try{
    undefinedfunction()
}
catch(e){
    //catch and just suppress error
}

 

try{
    undefinedfunction()
    alert('I guess you do exist')
}
catch(e){
    alert('An error has occurred: '+e.message)
}

 

try{
    undefinedfunction()
    alert('I guess you do exist')
}
catch(e){
    alert('An error has occurred: '+e.message)
}
finally{
    alert('I am alerted regardless of the outcome above')
}

 

var ajaxrequest=null
if (window.ActiveXObject){ //Test for support for different versions of ActiveXObject in IE
    try {
        ajaxrequest=new ActiveXObject("Msxml2.XMLHTTP")
    }
    catch (e){
        try{
        ajaxrequest=new ActiveXObject("Microsoft.XMLHTTP")
        } //end inner try
        catch (e){
            alert("I give up. Your IE doesn't support Ajax!")
        } //end inner catch
    } //end outer catch
}
else if (window.XMLHttpRequest) // if Mozilla, Safari etc
    ajaxrequest=new XMLHttpRequest()
 
ajaxrequest.open('GET', 'process.php', true) //do something with request

 

function change_list(){
  var q=document.getElementById("search_input");
  var str=trim(q.value);
  if(str!=""){
    new Ajax.Request("/friend/find", {
    method: "post",
    parameters: "query="+str,
    evalScripts: true,
    onComplete:    function(request) { element.fire("ajax:complete", request); },
    onSuccess:     function(request) { element.fire("ajax:success",  request); },
    onFailure:     function(request) { element.fire("ajax:failure",  request); }
     });
  }  
}

 

function change_group(id,grp){
  jQuery.ajax({
  type:"post",
  url:"/friend/change_group",
  dataType: "json", 
  data:{user_id: id,group: grp},
  success:function (result, textStatus) {
		if(textStatus == "success"){	  
			jQuery("#list"+result.jsonReturn[0]).hide();
			jQuery("#group"+result.jsonReturn[0]).html(result.jsonReturn[1]);
		}
   }
  });
}