What is formData

A way to construct a set of key/value pairs representing form fields and their values.

• Encoding type of: "multipart/form-data".

formData makes it easy to send data to a server using XMLHttpRequest or the fetch API.

formData is used to send complex data like files and audio:

const formData = new FormData();

formData.append('field_name', audioBlob, 'file_name.mp3'););

Audio can be attached as a Blob or File in-memory.

• when you record audio directly in the browser, it is stored as a Blob.

let blob = new Blob(recordingFile, { type: "audio/ogg" });
let file = new File([blob], 'recording.ogg');

const data = {
  "user" : "test",
};

const formData = new FormData();
formData.append('files.file', file);
formData.append('data', JSON.stringify(data));