countDownJs

enhancement on javascript original interval , based on setTimeout

usage :

var runTimes = 3 , timeInterval = 1000;
countDown(startFunc,intervalFunc,endFunc,runTimes,timeInterval);

In web development , we usually need to use count down feature like sending text password, reading agreement lisence etc.

We use to do it below :

var count = 10,handler;
var $btn = $('button[name="sendMePassword"]');
$btn.on('click',function(){
    $btn.prop('disabled',true).html('please waiting for '+(count)+' seconds');
    // call back end service
    $.get('sendpassword',function(){
        //ok function
        $btn.html('send ok');
    },function(res){
        clearInterval(handler);
        $btn.html('failed:'+res);
        $btn.prop('disabled',false);
    });
    // call back end service
    handler = setInterval(function(){
        $btn.html('please waiting for '+(count--)+' seconds');
        if(count ==0){
            $btn.prop('disabled',false);
            count = 10;
            clearInterval(handler);
        }
    })
});

As you can see above , it's quite hard to read , too much vairables makes it easy to make mistake , not mention being accidently changed value by other js because count and handler are quite common varible names we used a lot. most of your time is focus on how to implement the interval and not to make mistake , this is frastrating .

How about compared with this:

var $btn = $('button[name="sendMePassword"]');
$btn.on('click',function(){
    var h = countDown(function(time,totalTime,timeInterval){      //begin
        $btn.prop('disabled',true).html('please waiting for '+totalTime+' seconds');
    },function(time,totalTime){      //every 1 second
        $btn.html('please waiting for '+(totalTime - time)+' seconds');
    },function(){        //end
        $btn.prop('disabled',false).html('click to send password');
    },10,1000);
    
    // call back end service
    $.get('sendpassword',function(){
        //ok function
        console.log('send ok');
    },function(res){
        h.interrupt(); //this will clear all and run endFunc
        console.log('failed:'+res);
    });
});

countDown return an handler object

functions of handler:

clear : end the interval immediatelly

interrupt : end the interval immediatelly and run endfunc

pause : pause the interval loop

resume : resume the interval loop from where it is paused

repeat is not supported yet. Maybe in future feature.