Thinkphp6 output QR code image format to solve the conflict with debug

demand , Dynamically output QR code pictures .

If it's on Debug Pattern , There is interference from debugging tools , The picture cannot be displayed normally , If there is no such problem in the formal environment . But I started in a formal environment debug Pattern , Debug error , Then the problem is GG 了 .

like this ：

An extreme approach is direct echo picture exit , Just do it

        header('Content-Type:'.$result->getMimeType());
        echo  $result->getString();
        exit;

In this way, you can output pictures

If only to complete the requirements , Just as above .

As a good programmer, you should not compromise for the framework , But fix it .

Whether to use exit perhaps die End your program , It's not recommended ：

The exit(...) and die(...) statements should absolutely not be used in Web PHP pages as this might lead to a very bad user experience. In such case, the end user might have the feeling that the web site is down or has encountered a fatal error.

But of course PHP can also be used to develop command line application and in such case use of exit(...) or die(...) statement can be justified but must remain limited and not spread all over the application. We expect exceptions to be used to handle errors and those exceptions should be caught just before leaving the application to specify the exit code with help of exit(...) or die(...) statements.

Reference resources ： “exit(…)” and “die(…)” statements should not be used

Find the problem

Since it is debug The problem of , I put debug Just turn it off

$this->app->debug(false);

But the debugging toolbar still appears , ultimately , Find a way to deal with trace Class , To find out .

    public function handle($request, Closure $next)
    {
    
        $debug = $this->app->isDebug();

        //  Register log listening 
        if ($debug) {
    
            $this->log = [];
            $this->app->event->listen(LogWrite::class, function ($event) {
    
                if (empty($this->config['channel']) || $this->config['channel'] == $event->channel) {
    
                    $this->log = array_merge_recursive($this->log, $event->log);
                }
            });
        }

        $response = $next($request);
		
        // Trace Debug injection 
        if ($debug) {
    
            $data = $response->getContent();
            $this->traceDebug($response, $data);
            $response->content($data);
        }


        return $response;
    }

Trace Service registration ：

  public function register()
    {
    
        $this->app->middleware->add(TraceDebug::class);
    }

$response = $next($request); Middleware , The above is the record of the log , The following is the processing after the request is completed . You can see what you get here isDebug It is copied when the framework is loaded , That is to say, we modify it in the controller app In container debug It's invalid .

Change your mind

In the bottom judgment , If the return object is json, perhaps ajax The direct display of debug, therefore $contentType There should be no problem changing to image format .

    public function output(App $app, Response $response, array $log = [])
    {
    
        $request     = $app->request;
        $contentType = $response->getHeader('Content-Type');

        if ($request->isJson() || $request->isAjax()) {
    
            return false;
        } elseif (!empty($contentType) && strpos($contentType, 'html') === false) {
    
            return false;
        } elseif ($response->getCode() == 204) {
    
            return false;
        }
		.
		.
		.

Look directly at the control output Respose Class processing , here Respose The creation of requires input and output content types , Find according to the namespace think Framework file

    public static function create($data = '', string $type = 'html', int $code = 200): Response
    {
    
        $class = false !== strpos($type, '\\') ? $type : '\\think\\response\\' . ucfirst(strtolower($type));

        return Container::getInstance()->invokeClass($class, [$data, $code]);
    }

See light suddenly , The original output needs a file format , There happens to be no picture format here , So you need to create a class of image format by yourself ：

<?php

namespace app\common\service\system\think;

use think\Cookie;
use think\Response;

class Image extends Response
{
    

    /** *  Output type * @var string */
    protected $contentType = 'image/png';

    public function __construct( $data = '', int $code = 200)
    {
    
        $this->init($data, $code);
    }
}

Introduce the custom class , It can be avoided exit Bring risks

        $content =   $result->getString();
        $res = Response::create($content,Image::class);
        return $res;

It's written very loosely , Make a note of , Ideas for finding problems , I hope it helps you