Validate xml mime type in Laravel - laravel

Question

I have a validator set up to check if the document we upload is an XML file
if ($request->input('action') == 'upload_document') {
$validator = Validator::make($request->all(), [
'file' => 'bail|required|mimes:application/xml,xml|max:10000',
]
);
}
But when I do my upload, this validator triggers me an error "File must e of type application/xml,xml" even when I drop a real XML file with a .xml extension.
I have in my php.ini config extension=php_fileinfo.dll of course

Answer 1

Note that mime type validation instruct Laravel to read the content of the file to determine its type, so changing an image extension from .jpg to .xml will not trick it
From the Docs
mimes:foo,bar,...
The file under validation must have a MIME type corresponding to one of the listed extensions.
Basic Usage Of MIME Rule
'photo' => 'mimes:jpeg,bmp,png'
Even though you only need to specify the extensions, this rule actually validates against the MIME type of the file by reading the file's contents and guessing its MIME type.
A full listing of MIME types and their corresponding extensions may be found at the following location: https://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types
So make sure your file is an actual valid xml file (try this with phpunit.xml) from your Laravel project
Route::post('/', function (Request $request) {
if ($request->input('action') == 'upload_document') {
$validator = Validator::make(
$request->all(),
[
'file' => 'bail|required|mimes:application/xml,xml|max:10000',
]
);
$validator->validate();
dd('the file is valid');
}
});
And a form like this
<form method="post" enctype="multipart/form-data">
#csrf
<input name="action" value="upload_document">
<input type="file" name="file">
<button type="submit">Submit</button>
</form>
#error('file')
{{ $message }}
#enderror
Result:
"the file is valid"
But when testing with image.xml
The file must be a file of type: application/xml, xml.
 Alternatively, you can validate by extension
Route::post('/', function (Request $request) {
if ($request->input('action') == 'upload_document') {
$request->validate([
'file' => [
'bail',
'required',
'max:10000',
function ($attribute, $value, $fail) {
if ($value->getClientMimeType() !== 'text/xml') {
$fail($attribute.'\'s extension is invalid.');
}
},
]
]);
dd('the file is valid');
}
});
Now an image file with the xml extension passes the validation
See using closures for custom validation

Answer 2

It seems that the XML provided by an external company is not respecting the proper XML standard.
As it is not on my hands, I won't reformat it and I will have to manage it as text only. So I guess I can't use a validator in my case.

Answer 3

For those who try to pass xml extension on Laravel 5 (like me).
This will work with other additional extensions also.
Since Laravel ExtensionGuesser allows to add custom guesser via method register we do the folowing.
Make new class with own extensions array. I've made it exdending the original one so it corresponds the interface. I've put it to Helpers folder.
<?php
namespace App\Helpers;
use Symfony\Component\HttpFoundation\File\MimeType\MimeTypeExtensionGuesser;
/**
* Provides a best-guess mapping of mime type to file extension.
*/
class PriorExtensionGuesser extends MimeTypeExtensionGuesser
{
/**
* Addition to pretty old map of mime types and their default extensions.
*
* #see http://svn.apache.org/repos/asf/httpd/httpd/trunk/docs/conf/mime.types
*/
protected $defaultExtensions = array(
'text/xml' => 'xml',
);
}
In you controller (don't forget use statement):
use Symfony\Component\HttpFoundation\File\MimeType\ExtensionGuesser;
public function store (Request $request) {
if ($request->hasFile('file')) {
$guesser = ExtensionGuesser::getInstance(); //take the guesser who will guess
$guesser->register(new \App\Helpers\PriorExtensionGuesser()); //add own guesser
$validator = Validator::make($request->all(), [
'file' => 'file|mimes:txt,xls,xlsx,csv,xml|max:32768',
]);
if ($validator->fails()) {
.....
So now guesser checks our array in Prior* class then goes to original one.