cakephp2 can't get file data array through $this->request->data - ajax

Question

usually, we get all the data we need from $this->request->data. but if I'm using ajax file upload, I can't get that data e.g: tmp_name, size, etc.
my javascript code is like:
function uploadFile(file_blob_chunk, file_name, file_part, total_file_chunk, file_id) {
fd = new FormData();
fd.append("file_for_upload", file_blob_chunk);
fd.append("somestring", "This is some extra data");
xhr = new XMLHttpRequest();
xhr.open("POST", "files/index/" + file_id + '/' + file_part, true);
//Onload happened after file finished uploaded
xhr.onload = function(e) {
//alert(file_name + "done");
};
xhr.upload.addEventListener("progress", function(evt) {
if (evt.lengthComputable) {
}}, false);
xhr.send(fd);
}
and in FilesController.php
public function index($file_id = null, $file_part = null) {
if ($this->request->is('post')) {
//I can't use $this->request->data, to get the file details
}
}
If I use
debug($this->request->data);
I will only get
array(
'somestring' => 'This is some extra data'
)
I can't get the file data
Unless Im using debug($_FILES), I won't get
array(
'file_for_upload' => array(
'name' => 'blob',
'type' => 'application/octet-stream',
'tmp_name' => 'C:\xampp\tmp\phpAC42.tmp',
'error' => (int) 0,
'size' => (int) 9304862
)
)

Answer 1

If you want to use $this->request->data your post data should be in the format cake expects, eg: data[Model][some_field]
you have CustomField