How to troubleshoot laravel errors

In the development process using the Laravel framework, various errors or exceptions will inevitably occur. How to quickly troubleshoot errors and solve problems is a challenge faced by basic developers. This article will introduce you to the troubleshooting methods for Laravel errors and help you get twice the result with half the effort during the development process.

1. Logging

Laravel will record log information in different files according to different levels (debug, info, notice, warning, error, critical, alert, emergency). We can quickly find errors in the code by looking at the log files.

1.1 View log files

Open the storage/logs directory in the project root directory, and you can see the laravel.log file. This is the total log file of all levels of logs in the system. If you want to use a certain Different levels can be configured in the config/logging.php file to collect log records;

In the log file, you can filter and view error information based on time, process, level and other conditions. The specific usage is as follows:

tail -f storage/logs/laravel.log // 监控最新的日志内容，按Ctrl+C停止
cat storage/logs/laravel.log | grep '关键字' // 搜索包含"关键字"的日志内容
tail -n 100 storage/logs/laravel.log | grep '关键字' // 查看最后100行日志是否包含"关键字"

1.2 Level setting

Through Laravel’s own directory app/Exceptions/Handler.php class, you can see that the log level is set in the report() function In the first parameter, Laravel's default log level is error, which means that only logs with error level and above will be recorded in the app/public/storage/logs/laravel.log log file.

If you want to write all warning level and above logs to the log file, you can add the starting level in the first parameter of the report() function, as shown below:

public function report(Exception $exception)
{
    if ($this->shouldReport($exception)) {
        Log::channel('daily')->warning('遇到错误啦！', [
            'error' => $exception->getMessage()
        ]);
    }

    parent::report($exception);
}

Through the Log::channel('daily')->warning() operation, the error information and level are written to the log, and the shouldReport() method is used to determine whether it needs to be written to the log.

2. Exception handling

In Laravel applications, the way to throw custom exceptions is very simple. You only need to perform the following operations:

2.1 Custom exceptions

Create a new exception class and inherit Laravel's default Exception class, as shown below:

namespace AppExceptions;
use Exception;

class CustomException extends Exception
{
    public function __construct($message = null, $code = 0)
    {
        parent::__construct($message, $code); // 调用父类的构造方法
    }
     public function report()
    {
        // 记录错误日志 
        Log::error('CustomException：'.$this->getMessage());
    }

    public function render($request)
    {
        return response()->json(['message' => $this->getMessage()], Response::HTTP_INTERNAL_SERVER_ERROR);
    }
}

In the construction method, we can define exception information and status codes, and report them in report() The error log is recorded in the method, and the exception information and status code in JSON format are returned in the render() method.

When a CustomException occurs in the application, Laravel will automatically execute the report() method to record the error information to the log file, and return the exception information to the front end through the render() method.

2.2 Trigger exception

Use the throw new CustomException () method in the code to throw an exception, as shown below:

public function test(Request $request)
{
    // ...
    if (! check_validate($request->all())) {
        throw new CustomException('请求参数不正确');
    } 
}

3. Error debugging

When developing or testing, sometimes it is necessary to type debugging information in the code to find the problem. In Laravel, we can quickly output debugging information and interrupt program execution through the dump() and dd() functions. result.

3.1 dump() and dd()

The dump() function is used to print the contents of variables or arrays without interrupting the running of the program. Similar to PHP's built-in var_dump() function.

dd() function will not only print the contents of the variable or array, but also interrupt the execution of the program, and display the code stack processed to the current position and the specific information of the exception. Similar to PHP's built-in die() or exit() functions.

Route::get('/test', function () {
    dump('Hello Laravel!');
    return response()->json(['key' => 'value']);
});

Route::get('/test2', function () {
    $array = ['key_one' => 'value_one', 'key_two' => 'value_two'];
    dd($array);
    return response()->json(['key' => 'value']);
});

In the above code, we use the dump() and dd() methods to print the contents of strings and arrays. The usage is similar to PHP native functions, which is very convenient.

4. Conclusion

During the development process of Laravel, various error messages will always appear due to various reasons. How to efficiently troubleshoot and resolve these errors is a problem that every developer must face. In this article, we introduce several common troubleshooting methods such as Laravel logging, exception handling, and error debugging. We hope it will be helpful to you when developing in Laravel.

The above is the detailed content of How to troubleshoot laravel errors. For more information, please follow other related articles on the PHP Chinese website!