A small Symfony 2 class for returning a response as a CSV file. Based on the Symfony JsonResponse class.

CsvResponse.php

<?php

namespace Jb\AdminBundle\Http;

use Symfony\Component\HttpFoundation\Response;

class CsvResponse extends Response
{
    protected $data;

    protected $filename = 'export.csv';

    public function __construct($data = array(), $status = 200, $headers = array())
    {
        parent::__construct('', $status, $headers);

        $this->setData($data);
    }

    public function setData(array $data)
    {
        $output = fopen('php://temp', 'r+');

        foreach ($data as $row) {
            fputcsv($output, $row);
        }

        rewind($output);
        $this->data = '';
        while ($line = fgets($output)) {
            $this->data .= $line;
        }

        $this->data .= fgets($output);

        return $this->update();
    }

    public function getFilename()
    {
        return $this->filename;
    }

    public function setFilename($filename)
    {
        $this->filename = $filename;
        return $this->update();
    }

    protected function update()
    {
        $this->headers->set('Content-Disposition', sprintf('attachment; filename="%s"', $this->filename));

        if (!$this->headers->has('Content-Type')) {
            $this->headers->set('Content-Type', 'text/csv');
        }

        return $this->setContent($this->data);
    }
}

works like a charm, thanks a lot!

@mathewbyrne Could you please explain, why do you write to file and then read from it in the same method? I do not understand this approach.

An improved version based on Symfony\Component\Serializer\Encoder\CsvEncoder.

<?php

namespace App\Http;

use Symfony\Component\HttpFoundation\Response;

class CsvResponse extends Response
{
    private $data;
    private $filename;

    public function __construct($filename, $data = array(), $status = 200, $headers = array())
    {
        parent::__construct('', $status, $headers);
        $this->filename = $filename.'_'.md5(uniqid(rand(), true)).'.csv';
        $this->encode($data);
        $this->serve();
    }

    private function encode(array $data)
    {
        $handle = fopen('php://temp', 'w+');

        foreach ($data as $row) {
            fputcsv($output, $row);
        }

        rewind($handle);

        $this->data = stream_get_contents($handle);

        fclose($handle);
    }

    private function serve()
    {
        $this->headers->set('Content-Disposition', sprintf('attachment; filename="%s"', $this->filename));
        if (!$this->headers->has('Content-Type')) {
            $this->headers->set('Content-Type', 'text/csv');
        }

        return $this->setContent($this->data);
    }
}

Thanks.
@glauberm there's a small misprint in

foreach ($data as $row) { 
    fputcsv($output, $row); 
}

should be

foreach ($data as $row) { 
    fputcsv($handle, $row); 
}