How to determine if user selected a file for file upload?
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09-06-2019 - |
Question
If I have a
<input id="uploadFile" type="file" />
tag, and a submit button, how do I determine, in IE6 (and above) if a file has been selected by the user.
In FF, I just do:
var selected = document.getElementById("uploadBox").files.length > 0;
But that doesn't work in IE.
Solution
This works in IE (and FF, I believe):
if(document.getElementById("uploadBox").value != "") {
// you have a file
}
OTHER TIPS
this piece of code works in my local environment, hope it will also works in live
var nme = document.getElementById("uploadFile");
if(nme.value.length < 4) {
alert('Must Select any of your photo for upload!');
nme.focus();
return false;
}
function validateAndUpload(input){
var URL = window.URL || window.webkitURL;
var file = input.files[0];
if (file) {
var image = new Image();
image.onload = function() {
if (this.width) {
console.log('Image has width, I think it is real image');
//TODO: upload to backend
}
};
image.src = URL.createObjectURL(file);
}
};
<input type="file" name="uploadPicture" accept="image/*" onChange="validateAndUpload(this);"/>
Call this function on change .
You can use:
var files = uploadFile.files;
if (files.length == 0) { console.log(true) } else { console.log(false) }
if (files[0] == undefined) { console.log(true) } else { console.log(false) }
if (files[0] == null) { console.log(true) } else { console.log(false) }
All three give the same result.
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