move_uploaded_file() expects parameter 2 to be valid path, object given - php

Question

I'm using Symfony 2.3 to save a file uploaded by a form POST.
This is the code I use in the controller:
$fileDir = '/home2/divine/Symfony/src/App/Bundle/Resources/public/files';
$form['my_file']->getData()->move($fileDir, 'book.pdf');
Under water, Symfony executes this code to move the file:
move_uploaded_file("/tmp/phpBM9kw8", "/home2/divine/Symfony/src/App/Bundle/Resources/public/files/book.pdf");
The public directory has 777 permissions.
This is the error I get:
"Could not move the file "/tmp/phpBM9kw8" to "/home2/divine/Symfony/src/App/Bundle/Resources/public/files/book.pdf"
(move_uploaded_file() expects parameter 2 to be valid path, object given)"
I'm using PHP 5.3.
Update:
This is the code snipped that executes the move_uploaded_file():
// Class: Symfony\Component\HttpFoundation\File\UploadedFile
$target = $this->getTargetFile($directory, $name);
if (!#move_uploaded_file($this->getPathname(), $target)) {
// etc...
The $target" variable is created here:
protected function getTargetFile($directory, $name = null) {
// Some error handling here...
$target = $directory.DIRECTORY_SEPARATOR.(null === $name ? $this->getBasename() : $this->getName($name));
return new File($target, false);
}
The $target variable is therefor a File class. It does have a __toString() method, inherited from SplFileInfo:
/**
* Returns the path to the file as a string
* #link http://php.net/manual/en/splfileinfo.tostring.php
* #return string the path to the file.
* #since 5.1.2
*/
public function __toString () {}
But somehow that __toString method is not working.

Answer 1

But somehow that __toString method is not working
It is one of the “magic methods”, it gets called automatically when the object is used in a string context – so for example if you had 'foo' . $object.
But I don’t think it is supposed to work in this situation here. Because PHP is loosely typed, you can pass anything into move_uploaded_file. No automatic conversion to string will happen at this point. And then internally, the function only checks if the parameter is a string, but doesn’t try to convert it into one – because that would make little sense, it could be any kind of object, and there is no way of telling if calling __toString would result in a valid file path.
You might wonder now, why in the error message we do get to see the path:
Could not move the file "/tmp/phpBM9kw8" to "/home2/divine/Symfony/src/App/Bundle/Resources/public/files/book.pdf"
My guess is, that when that error message is assembled, there is string concatenation going on, so that __toString does get called at this specific point.
If you are willing to modify the Symfony source code, I think this should work as an easy fix, if you just change this line
if (!#move_uploaded_file($this->getPathname(), $target)) {
to
if (!#move_uploaded_file($this->getPathname(), ''.$target)) {
– then you have the situation again, where __toString will be called, because the object is transferred into a string context by concatenating it with a string (an empty one, because we don’t want to tamper with the resulting value.)
Of course modifying a framework’s files directly is not the most recommendable way of dealing with this – after the next update, our change might be lost again. I’d recommend that you check the Symfony bugtracker (they should have something like that) to see if this is a known issue already and if maybe an official patch file exists; and otherwise report it as a bug, so that it can be fixed in a future version.