Fine-uploader - add an asyc request to server before uploading each file?

Question

I am using Fine-uploader (traditional version) trying to let users upload files to our own server. The challenge I am having now is that I am supposed to get a token from server first before normal uploading process. The token will be sent along with each uploading request/chunk). This token is unique to each file, so this "request-for-token" step can start only after user has chosen a file.

I was thinking about putting something into "onSubmit" callback. But this "request-for-token" is an asyc call, which means the server's response will not come back right away. I don't know how to do it, or if that is the good way to do this.

Thanks for any help.

Answer 1

The onSubmit callback accepts a "thenable" return value. In other words, you can return a Promise, and Fine Uploader will wait before proceeding to the next step for that file until the returned promise is either resolved or rejected. For example:

var uploader = new qq.FineUploader({
   callbacks: {
      onSubmit: function(id, name) {
         return new Promise(function(resolve, reject) {
            // Send request to server, resolve() on success
            // ... reject() on failure.
            // Call this.setParams(tokenData, id)
            // ...to send the token w/ the upload request.
         })
      }
   }
})