show image file javascript code example

Example 1: preview image file upload javascript

<input type="file" accept="image/*" onchange="loadFile(event)">
<img id="output"/>
<script>
  var loadFile = function(event) {
    var output = document.getElementById('output');
    output.src = URL.createObjectURL(event.target.files[0]);
    output.onload = function() {
      URL.revokeObjectURL(output.src) // free memory
    }
  };
</script>

Example 2: show image javascript

HTML:
<img id="theImage" src="yourImage.png">
<a id="showImage">Show image</a>

JavaScript:
document.getElementById("showImage").onclick = function() {
    document.getElementById("theImage").style.visibility = "visible";
}

CSS:
#theImage { visibility: hidden; }

Example 3: show image javascript

JS:
function setImageVisible(id, visible) {
    var img = document.getElementById(id);
    img.style.visibility = (visible ? 'visible' : 'hidden');
}

HTML:
<img id="myImageId" src="yourImage.png">
Then, your links would be:
<a href="javascript:setImageVisible('myImageId', true)">show image</a>
<a href="javascript:setImageVisible('myImageId', false)">hide image</a>

CSS:
#theImage { visibility: hidden; }

Example 4: how to display image before upload in jhtml

function display(input) {
   if (input.files && input.files[0]) {
      var reader = new FileReader();
      reader.onload = function(event) {
         $('#myid').attr('src', event.target.result);
      }
      reader.readAsDataURL(input.files[0]);
   }
}

$("#demo").change(function() {
   display(this);
});