laravel 5.1 Request::ajax return false - ajax

Question

Hello i use same script for Laravel 4.2 and Laravel 5.1 and problem is for Laravel 4.2 work perfectly, but on Laravel 5.1 i can't understand why it's return bad result
Problem is why I got $request->ajax() false for Laravel 5.1?
routes.php
Route::post('/upload-image', [
'as' => 'upload-image-post',
'uses' => 'PageController#profileImage'
]);
PageController.php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Http\Requests;
use App\Http\Controllers\Controller;
class PageController extends Controller
{
public function profileImage(Request $request)
{
//here is problem
//result good: (Laravel 4.2 shows true)
//result bad: (Laravel 5.1 shows false)
var_dump($request->ajax());
}
}
upload-image.blade.php (js)
<script>
jQuery(document).ready(function($) {
$('#upload_image').click(function(event) {
$('#image').trigger('click');
});
$('#image').change(function(event) {
/* Act on the event */
$('#imageform').submit();
});
$('#imageform').ajaxForm({
beforeSubmit: function() {
},
success: function(msg) {
},
error: function(request, status, error) {
},
complete: function(xhr) {
if(xhr.status != 401) {
$('#image').val('');
result = xhr.responseText;
result = $.parseJSON(result);
if( !$.isEmptyObject(result.file_base_url) ) {
var img = new Image();
img.onload = function() {
$('#register_profile_photo').attr('src', img.src);
$('#register_profile_photo').attr('alt', result.image_alt);
//spinner.stop();
$('#upload-image-error').text('');
}
img.src = result.file_base_url;
} else {
$('#upload-image-error').text(result.image[0]);
}
}
}
});
});
upload-image.blade.php (html)
<form enctype="multipart/form-data" name='imageform' role="form" id="imageform" method="post" action="{!! route('upload-image-post') !!}">
{!! csrf_field() !!}
<div style="display:none;">
<input type="file" name="image" id="image" placeholder="Please choose your image" >
</div>
</form>
<div class="profile-img">
<img style="float: right" id="register_profile_photo" src="default.png" alt="Default image">
<div style="float: right" class="img-edit">Edit picture</div>
</div>
PS. If you test for laravel 4.2 this code need change from "{!! .. !!}" to "{{ .. }}"

Answer 1

I do not think this problem is caused by Laravel version. Laravel sources show, that ajax() call is propagated to Symfony's request component. And that source changed good 5 years back.
You should trace if X-Requested-With header is sent to your application in both cases. You can also set breakpoint to Symfony\Component\HttpFoundation\Request::isXmlHttpRequest() and see what you have in headers.