php - Use Laravel to Download table as CSV

Question

I am trying to export a database table using Laravel as a csv file. I would like the user to be able to select the Export as CSV button and download the table as a csv file. Currently I've gotten this code but It is not working:

my button:

<a href="/all-tweets-csv" class="btn btn-primary">Export as CSV</a>

my route:

Route::get('/all-tweets-csv', function(){

    $table = Tweet::all();
    $filename = "tweets.csv";
    $handle = fopen($filename, 'w+');
    fputcsv($handle, array('tweet text', 'screen name', 'name', 'created at'));

    foreach($table as $row) {
        fputcsv($handle, array($row['tweet_text'], $row['screen_name'], $row['name'], $row['created_at']));
    }

    fclose($handle);

    $headers = array(
        'Content-Type' => 'text/csv',
    );

    return Response::download($handle, 'tweets.csv', $headers);
});

It returns me this error:

 The file "Resource id #154" does not exist

And I've gathered that it is because it is trying to download a file that does not exist. Is there an alternative way I can go about modifying my code in order to download as a csv.

Answer 1

I stumbled in here trying to see if Laravel had something built in by default - the answers for this question worry me a bit. I agree with @andré-daniel that the proper method is to not write a file first, but his implementation is manually putting together the values, which would fail if any value contained quotes, spaces, etc.

This is a more robust solution, using Laravel's Response::stream and php's fputcsv to format each line properly (will escape quotes, and quote necessary strings. see http://php.net/manual/en/function.fputcsv.php for details)

<?php

public function download()
{
    $headers = [
            'Cache-Control'       => 'must-revalidate, post-check=0, pre-check=0'
        ,   'Content-type'        => 'text/csv'
        ,   'Content-Disposition' => 'attachment; filename=galleries.csv'
        ,   'Expires'             => '0'
        ,   'Pragma'              => 'public'
    ];

    $list = User::all()->toArray();

    # add headers for each column in the CSV download
    array_unshift($list, array_keys($list[0]));

   $callback = function() use ($list) 
    {
        $FH = fopen('php://output', 'w');
        foreach ($list as $row) { 
            fputcsv($FH, $row);
        }
        fclose($FH);
    };

    return response()->stream($callback, 200, $headers)
}