I'm using ajax to send file via POST request to the server (my Flask app), but I can only retrieve this file (binary data) in Flask using request.form, not request.files, and request.files is desired. Code as below.
How can I get file with request.files ? (Conversely, with Postman and other tools, I can get the file with request.files. In request.form case, info such as content-type is missing)
// "file_content" is read previously
var formData = new FormData();
formData.append("file", file_content);  // "file_content" is binary data
.ajax({
  type:"POST",
  async: false,
  url: ...,
  data: formData,
  dataType:"json",
  processData: false,
  contentType: false,
});
The tricky thing is send a local file, and most relevant answers are using document.getElementById().
