php类路径不是调用其方法的文件路径

I want to create a class in php to upload files and validate file information before doing it. My class is not in the root directory. The structure is something like this:

-project
    -root
        index.php
-src
    -classes
        class.file.php
    -files
        myFile.txt

My file class is like this:

<?php
Class File {
    public function uploadFile($file) {
        $target = "../files/" . basename($file['name']);
        //some additional validation
        if(move_uploaded_file($file['tmp_name']) {
            return true;
        } else {
            return false;
        }
    }
}

And finally my index file is:

<?php
include '/../../classes/class.file.php';
$objFile = new File();
if(isset($_POST['uploadFile']) && isset($_FILES['txtFile'])) {
    if($objFile->uploadFile($_FILES['txtFile')) {
        echo "file uploaded";
    } else {
        echo "file not uploaded";
    }
}
?>

The problem I have is that this will only work if the relative target path is from the php file where the method is called. I can't use absolute path. How can I set my uploadFile method to work with the proper path no matter where it is called? Please be nice is one of my first projects in php.

You're using an absolute file path for your include (with the leading forward slash) but you are using a relative file path in your files class for the upload location ($target).

Try switching to an absolute file path. Also, the use of the realpath function and the __DIR__ and __FILE__ magic constants will help you here.

Instead of include '/../../classes/class.file.php'; use: include dirname(FILE).'/../../classes/class.file.php';

If you use an autoloader then you can make all of your includes relative to your autoloader path.

Even better you can use Composer and configure your project to use PSR-0 or PSR-4 standards.