You can preview an image before it is uploaded without using AJAX the following way:
imgInp.onchange = evt => {
const [file] = imgInp.files
if (file) {
blah.src = URL.createObjectURL(file)
}
}<form runat="server">
<input accept="image/*" type='file' id="imgInp" />
<img id="blah" src="#" alt="your image" />
</form>How to preview an image before it is uploaded?
There are a couple ways you can do this. The most efficient way would be to use URL.createObjectURL() on the File from your <input>. Pass this URL to img.src to tell the browser to load the provided image.
Here’s an example:
<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>You can also use FileReader.readAsDataURL() to parse the file from your <input>. This will create a string in memory containing a base64 representation of the image.
<input type="file" accept="image/*" onchange="loadFile(event)">
<img id="output"/>
<script>
var loadFile = function(event) {
var reader = new FileReader();
reader.onload = function(){
var output = document.getElementById('output');
output.src = reader.result;
};
reader.readAsDataURL(event.target.files[0]);
};
</script>Answer #3:
One-liner solution:
The following code uses object URLs, which is much more efficient than data URL for viewing large images (A data URL is a huge string containing all of the file data, whereas an object URL, is just a short string referencing the file data in memory):
<img id="blah" alt="your image" width="100" height="100" />
<input type="file"
onchange="document.getElementById('blah').src = window.URL.createObjectURL(this.files[0])">Generated URL will be like this:
blob:http%3A//localhost/7514bc74-65d4-4cf0-a0df-3de016824345Answer #4:
THIS IS THE SIMPLEST METHOD
To PREVIEW the image before uploading it to the SERVER from the Browser without using Ajax or any complicated functions.
It needs an “onChange” event to load the image.
function preview() {
frame.src=URL.createObjectURL(event.target.files[0]);
}<form>
<input type="file" onchange="preview()">
<img id="frame" src="" width="100px" height="100px"/>
</form>Answer #5:
The answer shared above works well in “standard” browsers like FF and Chrome. The solution for IE exists but looks different. Here description of the cross-browser solution:
In HTML we need two preview elements, img for standard browsers and div for IE
HTML:
<img id="preview"
src=""
alt=""
style="display:none; max-width: 160px; max-height: 120px; border: none;"/>
<div id="preview_ie"></div>
In CSS we specify the following IE-specific thing:
CSS:
#preview_ie {
FILTER: progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)
}
In HTML we include the standard and the IE-specific Javascripts:
<script type="text/javascript">
{% include "pic_preview.js" %}
</script>
<!--[if gte IE 7]>
<script type="text/javascript">
{% include "pic_preview_ie.js" %}
</script>
The pic_preview.js is the Javascript from the LeassTaTT’s answer. Replace the $('#blah') with the $('#preview') and add the $('#preview').show()
Now the IE-specific Javascript (pic_preview_ie.js):
function readURL (imgFile) {
var newPreview = document.getElementById('preview_ie');
newPreview.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = imgFile.value;
newPreview.style.width = '160px';
newPreview.style.height = '120px';
}
That’s is. Works in IE7, IE8, FF and Chrome. Please test in IE9 and report.
How to preview an image before it is uploaded?
Here’s the solution:
Html
<input type="file" accept="image/*" onchange="showMyImage(this)" />
<br/>
<img id="thumbnil" style="width:20%; margin-top:10px;" src="" alt="image"/>
JS
function showMyImage(fileInput) {
var files = fileInput.files;
for (var i = 0; i < files.length; i++) {
var file = files[i];
var imageType = /image.*/;
if (!file.type.match(imageType)) {
continue;
}
var img=document.getElementById("thumbnil");
img.file = file;
var reader = new FileReader();
reader.onload = (function(aImg) {
return function(e) {
aImg.src = e.target.result;
};
})(img);
reader.readAsDataURL(file);
}
}How to show a preview of multiple images before uploading?
Here’s a multiple files version, based on the first answer.
The HTML
<input type="file" multiple id="gallery-photo-add">
<div class="gallery"></div>
JavaScript / jQuery
$(function() {
// Multiple images preview in browser
var imagesPreview = function(input, placeToInsertImagePreview) {
if (input.files) {
var filesAmount = input.files.length;
for (i = 0; i < filesAmount; i++) {
var reader = new FileReader();
reader.onload = function(event) {
$($.parseHTML('<img>')).attr('src', event.target.result).appendTo(placeToInsertImagePreview);
}
reader.readAsDataURL(input.files[i]);
}
}
};
$('#gallery-photo-add').on('change', function() {
imagesPreview(this, 'div.gallery');
});
});
Requires jQuery 1.8 due to the usage of $.parseHTML, which should help with XSS mitigation.
This will work out of the box, and the only dependency you need is jQuery.
Answer #7- example with multiple images using JQuery:
JavaScript (jQuery)
function readURL(input) {
for(var i =0; i< input.files.length; i++){
if (input.files[i]) {
var reader = new FileReader();
reader.onload = function (e) {
var img = $('<img id="dynamic">');
img.attr('src', e.target.result);
img.appendTo('#form1');
}
reader.readAsDataURL(input.files[i]);
}
}
}
$("#imgUpload").change(function(){
readURL(this);
});
}
Markup (HTML)
<form id="form1" runat="server">
<input type="file" id="imgUpload" multiple/>
</form>Hope you learned something from this post.
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