Zend Framework 2 - Rendering CSV data

Question

i have a model that returns car data with id, name, price etc. So i have a car controller and a csv action that fetches this data from a model:

$carTable = $this->getServiceLocator()->get('Application\Model\DbTable\Cars');
$cars = $carTable->fetchAll();

i need to download this "$cars" data as a CSV file, so the user can store it on the disk.

I have tried to disable the layout and echo a CSV string and setting "content-type" and other headers, but it didn't work out of the box. Then i figured out that i should probably create a custom CsvRenderer and register it in configuration.

Since i couldn't find any documentation about this on the ZF2 site or in blogs and Stackoverflow answers, i would like to know if this is the recommended general approach for downloading data as CSV in ZF2? or is there a simpler solution that i am not aware of?

Thanks

Answer 1

Since we are talking about ZF2, I would rather solve this by adding a new CSV ViewStrategy/Renderer/ViewModel.

Here you can read more about implementing own rendering and response strategies: Zend Docs

or even here: http://zend-framework-community.634137.n4.nabble.com/ZF2-Implementing-custom-renderer-strategy-td4655896.html

That will turn the code in the controller slimmer, cleaner and more clear, since you don't have to care about the headers in the controller, but in the renderer. Then, each time you need a new CSV output, you don't have to write that action all over again, you just use the CSV View model

Answer 2

One solution would be to return a Response object directly from the controller.

Something like this stands a good chance of working:

public function downloadAction()
{
    // magically create $content as a string containing CSV data

    $response = $this->getResponse();
    $headers = $response->getHeaders();
    $headers->addHeaderLine('Content-Type', 'text/csv');
    $headers->addHeaderLine('Content-Disposition', "attachment; filename=\"my_filen.csv\"");
    $headers->addHeaderLine('Accept-Ranges', 'bytes');
    $headers->addHeaderLine('Content-Length', strlen($content));

    $response->setContent($content);
    return $response;
}

(Note that I haven't tested this code, but have updated in line with comment!)

Answer 3

This is based off the answer provided by Rob.

In Rob's answer, by assigning $response->getHeaders() to a new $headers variable, then applying the ->addHeaderLine to that new variable, it does not properly set the headers on the $response. So when returned, the headers were not attached to the response.

To fix this, simply add the headers directly to the $response shown below:

public function downloadAction()
{
    // magically create $content as a string containing CSV data

    $response = $this->getResponse();
    $response->getHeaders()
             ->addHeaderLine('Content-Type', 'text/csv')
             ->addHeaderLine('Content-Disposition', "attachment; filename=\"my_filen.csv\"")
             ->addHeaderLine('Accept-Ranges', 'bytes')
             ->addHeaderLine('Content-Length', strlen($content));

    $response->setContent($content);
    return $response;
}