I have read this and this questions which seems to suggest that the file MIME type could be checked using JavaScript on client side. Now, I understand that the real validation still has to be done on server side. I want to perform a client side checking to avoid unnecessary wastage of server resource. To test…
Tag: file-upload
How to get image size of a form field (formData) in Javascript
Any idea how to get size in bytes of an image within a validating javascript function so that user will be prompted to pick a valid image size. I have seen other answers which handle this out of the form logic, but I want to know if I can get the size within the validation javascript function. Thanks Here is
How to get full path of selected file on change of using javascript, jquery-ajax?
How to get full path of file while selecting file using <input type=‘file’> but the filePath var contains only name of selected file, not the full path. I searched it on net, but it seems that for security reasons browsers (FF,chrome) just give name of file. Is there any other way to get full path of se…
Check image width and height before upload with Javascript
I have a JPS with a form in which a user can put an image: I have written this js: which works fine to check file type and size. Now I want to check image width and height but I cannot do it. I have tried with target.files[0].width but I get undefined. With other ways I get 0. Any suggestions?
Upload file with Ajax XMLHttpRequest
I am trying to send file with XMLHttpRequest with this code. I get this error: T The request was rejected because no multipart boundary was found. What am I doing wrong? Answer There is no such thing as xhr.file = file;; the file object is not supposed to be attached this way. xhr.send(file) doesn’t sen…
How to tell if dragged contents is text or files during Javascript dragenter event
Using the dragenter event I show a dropzone on the webpage to have dropped files upload quickly, and it all works well. However, the dropzone also pops up when dragging selected text. How to tell the difference early on? I know that the drop event exposes all file contents to be iterated using dataTransfer.fi…
Validation of file extension before uploading file
I am uploading images to a servlet. The validation whether the uploaded file is an image is done in server side only, by checking the magic numbers in the file header. Is there any way to validate the extensions in client side before submitting the form to servlet? As soon as I hit enter it starts uploading. …
Client Checking file size using HTML5?
I’m trying to ride the HTML5 wave but I’m facing a small issue. Before HTML5 we were checking the file size with flash but now the trend is to avoid using flash in web apps. Is there any way to check the file size in the client side using HTML5? Answer This works. Place it inside an event listener…
JavaScript file upload size validation
Is there any way to check file size before uploading it using JavaScript? Answer Yes, you can use the File API for this. Here’s a complete example (see comments): Slightly off-topic, but: Note that client-side validation is no substitute for server-side validation. Client-side validation is purely to ma…
Does HTML5 allow drag-drop upload of folders or a folder tree?
I haven’t seen any examples that do this. Is this not allowed in the API spec? I am searching for an easy drag-drop solution for uploading an entire folder tree of photos. Answer It’s now possible, thanks to Chrome >= 21. More info: https://protonet.info/blog/html5-experiment-drag-drop-of-folde…