Calculate & Display percentage of progress of page load

Question

I have a loader which loads when page loads at the starting. I need to show the percentage of completion in it.

My application has lots of jquery and css included in it and it also include a ajax call.

As of now, I have displayed the progress bar when page load starts and hided it when the ajax completed successfully.

Also, I have displayed the percentage but increased it manually using the below code:

function timeout_trigger() {
    $(".progress").css("max-width", p + "%");
    $(".progress-view").text(p + "%");
    if (p != 100) {
        setTimeout('timeout_trigger()', 50);
    }
    p++;
}
timeout_trigger();

The problem here is, before the progress reaches 100, the page loads and the content is displayed and hence the loader is hided in between let say - at 60% - the loader is hided.

I want to calculate the percentage of page load completion (ie. jquery loading time, css loading time etc) dynamically and increase the progress accordingly.

Please help to get through this..

Answer 1

You can use this:

Source: Display a loading bar before the entire page is loaded

Script

<script>
        ;(function(){
          function id(v){ return document.getElementById(v); }
          function loadbar() {
            var ovrl = id("overlay"),
                prog = id("progress"),
                stat = id("progstat"),
                img = document.images,
                c = 0,
                tot = img.length;
            if(tot == 0) return doneLoading();

            function imgLoaded(){
              c += 1;
              var perc = ((100/tot*c) << 0) +"%";
              prog.style.width = perc;
              stat.innerHTML = "Loading "+ perc;
              if(c===tot) return doneLoading();
            }
            function doneLoading(){
              ovrl.style.opacity = 0;
              setTimeout(function(){ 
                ovrl.style.display = "none";
              }, 1200);
            }
            for(var i=0; i<tot; i++) {
              var tImg     = new Image();
              tImg.onload  = imgLoaded;
              tImg.onerror = imgLoaded;
              tImg.src     = img[i].src;
            }    
          }
          document.addEventListener('DOMContentLoaded', loadbar, false);
        }());
    </script>

HTML (At the starting of body or at the end)

<div id="overlay">
            <div id="progstat"></div>
            <div id="progress"></div>
        </div>

CSS

#overlay{
  position:fixed;
  z-index:99999;
  top:0;
  left:0;
  bottom:0;
  right:0;
  background:rgba(0,0,0,0.9);
  transition: 1s 0.4s;
}
#progress{
  height:1px;
  background:#fff;
  position:absolute;
  width:0;
  top:50%;
  transition: 1s;
}
#progstat{
  font-size:0.7em;
  letter-spacing: 3px;
  position:absolute;
  top:50%;
  margin-top:-40px;
  width:100%;
  text-align:center;
  color:#fff;
}

Answer 2

function timeout_trigger() {
   $(".progress").css("max-width",p+"%");
   $(".progress-view").text(p+"%");
   if(p!=100) {
       setTimeout('timeout_trigger()', 50);
   }
   p++;
}
timeout_trigger();

This code will work only when you download 1% per 50ms, if download goes faster - if will fail.

It must be something like this:

var size = file.getsize(); // file size

function timeout_trigger() {
   var loaded = file.getLoaded(); // loaded part
   p = parseInt(loaded / size);

   $(".progress").css("max-width",p+"%");
   $(".progress-view").text(p+"%");
   if(p!=100) {
       setTimeout('timeout_trigger()', 20);
   }
}
timeout_trigger();

To realise method getLoaded() you can use AJAX event onprogress (I hope you are loading files async). Check Monitoring Progress part here https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/Using_XMLHttpRequest