标签上传图片文件。现在,它接受所有文件类型。但是,我想将其限制为仅包含 .jpg、.gif 等的特定图像文件扩展名。我怎样才能实现这个功能?" /> 标签上传图片文件。现在,它接受所有文件类型。但是,我想将其限制为仅包含 .jpg、.gif 等的特定图像文件扩展名。我怎样才能实现这个功能?"> 标签上传图片文件。现在,它接受所有文件类型。但是,我想将其限制为仅包含 .jpg、.gif 等的特定图像文件扩展名。我怎样才能实现这个功能?" />
I need to upload only image file through <input type="file">
tag.
Right now, it accepts all file types. But, I want to restrict it to only specific image file extensions which include .jpg
, .gif
etc.
How can I achieve this functionality?
Use the accept attribute of the input tag. To accept only PNG's, JPEG's and GIF's you can use the following code:
Or simply:
Note that this only provides a hint to the browser as to what file-types to display to the user, but this can be easily circumvented, so you should always validate the uploaded file on the server also.
It should work in IE 10+, Chrome, Firefox, Safari 6+, Opera 15+, but support is very sketchy on mobiles (as of 2015) and by some reports, this may actually prevent some mobile browsers from uploading anything at all, so be sure to test your target platforms well.
For detailed browser support, see http://caniuse.com/#feat=input-file-accept
Using this:
<input type="file" accept="image/*">
works in both FF and Chrome.
Use it like this
<input type="file" accept=".png, .jpg, .jpeg" />
It worked for me
https://jsfiddle.net/ermagrawal/5u4ftp3k/
Steps: 1. Add accept attribute to input tag 2. Validate with javascript 3. Add server side validation to verify if the content is really an expected file type
For HTML and javascript:
<html>
<body>
<input name="image" type="file" id="fileName" accept=".jpg,.jpeg,.png" onchange="validateFileType()"/>
<script type="text/javascript">
function validateFileType(){
var fileName = document.getElementById("fileName").value;
var idxDot = fileName.lastIndexOf(".") + 1;
var extFile = fileName.substr(idxDot, fileName.length).toLowerCase();
if (extFile=="jpg" || extFile=="jpeg" || extFile=="png"){
//TO DO
}else{
alert("Only jpg/jpeg and png files are allowed!");
}
}
</script>
</body>
</html>
Explanation:
The accept attribute filters the files that will be displayed in the file chooser popup. However, it is not a validation. It is only a hint to the browser. The user can still change the options in the popup. The javascript only validates for file extension, but cannot really verify if the select file is an actual jpg or png. So you have to write for file content validation on server side.
This can be achieved by
<input type="file" accept="image/*" />
But this is not a good way. you have to code on the server side to check the file an image or not.
Check if image file is an actual image or fake image
if(isset($_POST["submit"])) {
$check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
if($check !== false) {
echo "File is an image - " . $check["mime"] . ".";
$uploadOk = 1;
}
else {
echo "File is not an image.";
$uploadOk = 0;
}
}
For more reference, see here
http://www.w3schools.com/tags/att_input_accept.asp
http://www.w3schools.com/php/php_file_upload.asp
Using type="file" and accept="image/*" (or the format you want), allow the user to chose a file with specific format. But you have to re check it again in client side, because the user can select other type of files. This works for me.
<input #imageInput accept="image/*" (change)="processFile(imageInput)" name="upload-photo" type="file" id="upload-photo" />
And then, in your javascript script
processFile(imageInput) {
if (imageInput.files[0]) {
const file: File = imageInput.files[0];
var pattern = /image-*/;
if (!file.type.match(pattern)) {
alert('Invalid format');
return;
}
// here you can do whatever you want with your image. Now you are sure that it is an image
}
}
const file: File = imageInput.files[0];
? Also, assigning id to input is not done in conventional manner.
Just as an addition: if you want to include all modern image file types with the best cross-browser support it should be:
<input type="file" accept="image/apng, image/avif, image/gif, image/jpeg, image/png, image/svg+xml, image/webp">
This allows all image file types that can be displayed in most browsers while excluding less commons formats like TIFF or formats that are not suitable for the web like PSD.
you can use accept
attribute for <input type="file">
read this docs http://www.w3schools.com/tags/att_input_accept.asp
You can add specific type of image or other file type and do validation in your code :
<input style="margin-left: 10px; margin-top: 5px;" type="file" accept="image/x-png,image/jpeg,application/pdf"
(change)="handleFileInput($event,'creditRatingFile')" name="creditRatingFile" id="creditRatingFile">
handleFileInput(event) {
console.log(event);
const file = event.target.files[0];
if (file.size > 2097152) {
throw err;
} else if (
file.type !== "application/pdf" &&
file.type !== "application/wps-office.pdf" &&
file.type !== 'application/pdf' && file.type !== 'image/jpg' && file.type !== 'image/jpeg' && file.type !== "image/png"
) {
throw err;
} else {
console.log('file valid')
}
}
In html;
<input type="file" accept="image/*">
This will accept all image formats but no other file like pdf or video.
But if you are using django, in django forms.py;
image_field = forms.ImageField(Here_are_the_parameters)
If you want to upload multiple images at once you can add multiple
attribute to input.
upload multiple files:
Simple and powerful way(dynamic accept)
place formats in array like "image/*"
var upload=document.getElementById("upload"); var array=["video/mp4","image/png"]; upload.accept=array; upload.addEventListener("change",()=>{ console.log(upload.value) })
Other people's answers refactored for ReactJS (hooks)
import React from 'react';
const ImageUploader = () => {
const handleImageUpload = (e) => {
// If no file selected, return
if (e.target.files.length === 0) return false;
const file = e.target.files[0];
// If no image selected, return
if (!/^image\//.test(file.type)) {
alert(`File ${file.name} is not an image.`);
return false;
}
// ...
};
return (
<>
<input type='file' accept='image/*' onChange={(e) => handleImageUpload(e)} />
</>
);
};
export default ImageUploader;
Success story sharing
accept="file/csv, file/xls"
is it valid??image/x-png
? According to this list, it is justimage/png
. iana.org/assignments/media-types/media-types.xhtml