data:Url php with random numbers - php

Question

I need to write a function that returns a date:url picture with a random number, I’m absolutely confused, here are my attempts, tell me where to go next
$function = new \Twig\TwigFunction('picture', function () {
header("Content-Type: image/png");
$im = #imagecreate(50, 50)
or die("Невозможно создать поток изображения");
$background_color = imagecolorallocate($im, 0, 0, 0);
$text_color = imagecolorallocate($im, 233, 14, 91);
$string = rand();
imagestring($im, 1, 5, 5, $string, $text_color);
imagepng($im);
imagedestroy($im);
$img64 = base64_encode($im);
return $img64;
});
$twig->addFunction($function);

Answer 1

Issues:
header("Content-Type: image/png"); doesn't make any sense. Your function returns plain text that isn't even meant to be returned to browser as-is but injected inside HTML. Get rid of this line.
The # in #imagecreate(50, 50) is the error control operator. By default it'll just hide useful error messages from you. You don't possibly want it either.
You define $background_color but never use it. You can feed it to imagefill() or, if you want it black, omit it altogether.
imagepng($im) immediately prints the image. That's bad when you want to process and return it. You can capture with e.g. output control functions.
base64_encode($im) triggers:
Warning: base64_encode() expects parameter 1 to be string, resource
You're incorrectly assuming that imagecreate() returns the final image bytes; it doesn't. It returns a resource to be passed as argument to other image functions. You don't need it for anything else. Additionally, if you didn't see the message it can mean that you haven't configured PHP to display error messages.
There's no need to imagedestroy(). The image is local to the function, builtin garbage collector will take care.
Don't store the image bytes in temporary variables for no reason, that will only increase memory consumption.
So you basically need to understand that your code is not a black box and ensure that every line you write has a purpose known to you and is used as the corresponding manual page explains.
$im = imagecreate(50, 50)
or die("Невозможно создать поток изображения");
$text_color = imagecolorallocate($im, 233, 14, 91);
$string = rand();
imagestring($im, 1, 5, 5, $string, $text_color);
ob_start();
imagepng($im);
return base64_encode(ob_get_clean());