Plupload: run uploader.php even with no image loaded - php

Question

I'm using plupload to upload images in a form. When I press submit, the uploader.php does it job by uploading the images and processing the other form data using the multipart_params og pluploader.
However, I want to submit the form as well when no image is selected. When I submit with no image selected now, uploader.php simply doesn't run.
Is there a way to run uploader.php in all cases, even with no files selected?
Thanks.
This is the simplified code I'm working on:
<textarea id="textarea_input"></textarea>
<label id="browse" href="javascript:;">
<i class="fa fa-camera"></i> Add image
<span id="filelist"></span>
</label>
<a id="start-upload" href="javascript:;"">Add</a>
<span id="console"></span>
<script type="text/javascript">
var uploader = new plupload.Uploader({
browse_button: 'browse', // this can be an id of a DOM element or the DOM element itself
url: 'uploader.php',
multi_selection: false,
resize: {
width: 1500,
height: 1500,
quality: 30
},
filters: {
mime_types : [
{ title : "Image files", extensions : "jpg,gif,png,jpeg" }
],
max_file_size: "10mb",
prevent_duplicates: true
},
multipart_params : {
"textarea_input" : "value1" //predefine textarea_input here, uploader right before uploader.start()
}
});
uploader.init();
uploader.bind('FilesAdded', function(up, files) {
while (up.files.length > 1) { //custom: limit to 1 file upload.
up.removeFile(up.files[0]);
document.getElementById('filelist').innerHTML = '';
}
var html = '';
plupload.each(files, function(file) {
html += '<br /><span id="' + file.id + '">' + file.name + ' (' + plupload.formatSize(file.size) + ') <b></b></span>';
});
document.getElementById('filelist').innerHTML += html;
});
uploader.bind('UploadProgress', function(up, file) {
document.getElementById(file.id).getElementsByTagName('b')[0].innerHTML = '<span>' + file.percent + "%</span>";
});
uploader.bind('Error', function(up, err) {
document.getElementById('console').innerHTML += "\nError #" + err.code + ": " + err.message;
});
uploader.bind('UploadComplete', function(up, files) {
window.location = "mobilelogbook.php?saved=2";
});
document.getElementById('start-upload').onclick = function() {
uploader.settings.multipart_params["textarea_input"] = document.getElementById("textarea_input").value;
uploader.start();
};
</script>
And the uploader.php:
<?php
if (empty($_FILES) || $_FILES["file"]["error"]) {
$fileName = '';
} else {
$fileName = $_FILES["file"]["name"];
move_uploaded_file($_FILES["file"]["tmp_name"], "images/logbook/$fileName");
}
if (isset($_POST['textarea_input'])) {
$log = $_POST['textarea_input'];
} else {
$log = '';
}
// SQL GOES HERE: ADDS THE TEXTAREA_INPUT AND FILENAME TO A TABLE.
die('{"OK": 1}');
?>