file-upload
How to check a uploaded file whether it is an image or other file?
I’m assuming that you’re running this in a servlet context. If it’s affordable to check the content type based on just the file extension, then use ServletContext#getMimeType() to get the mime type (content type). Just check if it starts with image/. String fileName = uploadedFile.getFileName(); String mimeType = getServletContext().getMimeType(fileName); if (mimeType.startsWith(“image/”)) { // It’s an …
What is HTML5 File.slice method actually doing?
The important thing to keep in mind is that File inherits from Blob, File doesn’t actually have a slice method, it gets this method from Blob. File just adds a couple metadata attributes. The best way to think of a Blob (or File) is as a pointer to data, but not the actual data itself. …
Handling large file uploads with Flask
I think the super simple way to get around that simply sends the file in lots of small parts/chunks. So there are going to be two parts to making this work, the front-end (website) and backend (server). For the front-end part, you can use something like Dropzone.js which has no additional dependencies and decent CSS …
Detect MIME type of uploaded file in Ruby
The ruby-filemagic gem will do it: require ‘filemagic’ puts FileMagic.new(FileMagic::MAGIC_MIME).file(__FILE__) # => text/x-ruby; charset=us-ascii This gem does not look at the file extension at all. It reads a bit of the file contents and uses that to guess the file’s type.
How to read into memory the lines of a text file from an IFormFile in ASP.NET Core?
The abstraction for the IFormFile has an .OpenReadStream method. To prevent a ton of undesirable and potentially large allocations, we should read a single line at a time and build up our list from each line that we read. Additionally, we could encapsulate this logic in an extension method. The Index action ends up looking …
Why do browsers present selected files as coming from C:\fakepath\ instead of their true local path?
Some browsers have a security feature that prevents JavaScript from knowing your file’s local full path. It makes sense – as a client, you don’t want the server to know your local machine’s filesystem. It would be nice if all browsers did this.
Get the filename of a fileupload in a document through JavaScript
In google chrome element.value return the name + the path, but a fake path. Thus, for my case I used the name attribute on the file like below : function getFileData(myFile){ var file = myFile.files[0]; var filename = file.name; } this is the call from the page : <input id=”ph1″ name=”photo” type=”file” class=”jq_req” onchange=”getFileData(this);”/>
How to persist file upload fields after a rails validation error
Carrierwave is a great tool for handling file uploads and can handle this for you https://github.com/jnicklas/carrierwave#making-uploads-work-across-form-redisplays