gistfile1.txt

<?php

class SymfonyFile extends SplFileInfo
{
    public function __construct($path, $originalName, $mimeType = null, $size = null) {
        parent::__construct($path);
    }
}

class FileHandler
{
    // Needed to create a class-wide pointer to the temporary file, otherwise it'll be GC'ed
    protected $filePointer = null;

    // NB: you can get localpath this way
    public function localpath() {
        if ($this->file->isFile()) {
            return (string)$this->file;
        }
        return sys_get_temp_dir() . '/' . $this->getHash();
    }

    /**
     * Destruct the class and unlink the tempfile.
     *
     * @return void
     */
    /**
     * @codeCoverageIgnore
     */
    public function __destruct()
    {
        if ($this->delete && $this->file instanceof SymfonyFile && getenv('APP_ENV') !== 'testing') {
            unlink($this->localpath());
        }
    }

    /**
     * Set the file instance manually.
     *
     * @param  string $path
     * @param  string $originalName
     * @param  string $mimeType
     * @param  int    $size
     * @return void
     */
    public function setFile($path, $originalName, $mimeType, $size)
    {
        $this->file = new SymfonyFile($path, $originalName, $mimeType, $size);
    }

    /**
     * Create and set the file instance manually.
     *
     * @param  string $filename
     * @param  string $mimeType
     * @return bool
     */
    public function createFile($filename, $mimeType = 'text/csv')
    {
        $validMimeTypes = ['text/csv', 'application/xml', 'image/jpeg', 'image/gif', 'image/png'];

        // valid mime type?
        if ( ! in_array($mimeType, $validMimeTypes)) {
            return false;
        }

        // create file
        $this->filePointer = tmpfile();

        // get filepath
        $path = stream_get_meta_data($this->filePointer)['uri'];

        // set file
        $this->setFile($path, $filename, $mimeType, $size = 0);

        // success!
        return true;
    }

    /**
     * Read file.
     *
     * @return array
     */
    public function readFile()
    {
        // 1. create data placeholder
        $data = [];

        // 2. open file
        $file = $this->file->openFile('r+b');

        // 3. read!
        while ( ! $file->eof()) {
            $data[] = $file->fgets();
        }

        // 4. close file pointer
        $file = null;

        // 5. return data as array
        return $data;
    }

    /**
     * Write to file.
     *
     * @param  array $data
     * @return void
     */
    public function writeToFile($data)
    {
        // 1. open file
        $file = $this->file->openFile('r+b');

        // 2. write!
        $file->fwrite(implode(PHP_EOL, $data));

        // 3. get new size
        $size = $file->fstat()['size'];

        // 4. close file pointer
        $file = null;

        // 5. refresh SymfonyFile instance
        $path     = $this->localpath();
        $filename = $this->file->getClientOriginalName();
        $mimeType = $this->file->getClientMimeType();
        // TODO: check that $this->file->getClientSize() is returning size = 0
        $this->setFile($path, $filename, $mimeType, $size);
        // TODO: check that $this->file->getClientSize() is returning size bigger than 0
    }
}

$fileHandler = new FileHandler;
$filename    = time() . '.csv';
$data        = ['line1', 'line2', 'line3', 'line4', 'line5'];
$fileHandler->createFile($filename);
$fileHandler->writeToFile($data);
echo implode('', $fileHandler->readFile()) . "\n";