Default Configuration like outputBuffering, displayErrorDetails not working in slim 3

1

I am using slim version 3.8 and I want to disable outputBuffering and show all errors:
Following is my simple Hello World program.

require_once(dir.‘/vendor/autoload.php’);

$configuration = [
‘settings’ => [
‘displayErrorDetails’ => true,
“outputBuffering” => false,
],
];

$app = new \Slim\App($configuration);

// Add route callbacks
$app->get(‘/’, function ($request, $response, $args) {
echo “here”;
return $response->withStatus(200)->write(‘Hello World!’);
});

// Run application
$app->run();

If I comment echo “here”; then it works fine.
But this code is throwing exception - 500 internal error saying that “Unexpected data in output buffer. Maybe you have characters before an opening”.
Can someone please tell me what’s going wrong here?

2

I copied and pasted that code into my index.php file, added <?php to a blank line at the top and changed the require line to require __DIR__ . '/../vendor/autoload.php'; That is working fine for me. Also make sure you are not using a closing php tag at the bottom of the file.

Here is my index.php, it works with the echo line commented out as well.

<?php

require __DIR__ . '/../vendor/autoload.php';

$configuration = [
    'settings' => [
        'displayErrorDetails' => true,
        "outputBuffering" => false,
    ],
];

$app = new \Slim\App($configuration);

// Add route callbacks
$app->get('/', function ($request, $response, $args) {
    echo "here";
    return $response->withStatus(200)->write('Hello World!');
});

// Run application
$app->run();
3

I tried your code again. It’s still not working in my case. Following is my index.php file as corrected by you and there is no blank space at top and I am not using closing php tag.

<?php

require __DIR__ . '/../vendor/autoload.php';

$configuration = [
    'settings' => [
        'displayErrorDetails' => true,
        "outputBuffering" => false,
    ],
];

$app = new \Slim\App($configuration);

// Add route callbacks
$app->get('/', function ($request, $response, $args) {
    echo "here";
    return $response->withStatus(200)->write('Hello World!');
});

// Run application
try {
    $app->run();
} catch (\Exception $e) {
    print_r($e);// it's catching exception here.
}

In my case, it is throwing exception and I am getting 500 internal server error. If I comment out echo “here”, then it works fine.
Is it really running in your case without commenting out echo “here”??

4

I’ve fixed my problem doing this:

<?php

$configuration = [
    'settings' => [
        'displayErrorDetails' => true,
        "outputBuffering" => false,
        'addContentLengthHeader' => false,
    ],
];

I added the attribute addContentLengthHeader with the value false in the settings array and this solved problem.

By default, Slim adds a Content-Length header to the response with the length of the response. If there are characters added outside of the Slim response, the value for the Content-Length would be incorrect and this would result in characters being cut off in the browser (the browser ignores data after the content-length bytes).

5

Yes, without commenting out the echo and without adding the ‘addContentLengthHeader’. The reason/difference must be elsewhere. But, if I put in your try/catch then I get a 500 error.