How to print error messages in Laravel framework

In the development and debugging process of the Laravel framework, the processing of error and exception information is very critical. When it comes to handling error messages, printing error messages is a very important way. This article will introduce how to print error messages in the Laravel framework.

1. Error mechanism in Laravel

Errors in the Laravel framework are divided into two situations: exceptions and error messages. When an exception occurs in the code, the system will automatically throw an exception. In the writing of business code, error messages that appear require us to deal with them manually.

In the Laravel framework, error information processing is completed through the exception handler (Exception Handler). Exception handlers can catch exceptions thrown by applications, record exception data, and present user-friendly error messages.

2. Print error information

In the process of business code development, we often need to check the system error information, which is crucial for debugging and locating problems. In the Laravel framework, printing error messages is very simple.

When an error occurs in the application, we only need to output the print information in the web page. In the application, the statement to print the error message is very simple:

dd($error);

where $error is the error message.

dd() function is a debugging function provided in the Laravel framework, which can print out debugging information and end the execution of the program. During the development phase, we can use it to view the values ​​of variables, key values ​​of arrays, output of functions, etc. When we use the dd() function in the application, the page will display detailed debugging information and error information.

3. Printable error information

In the Laravel framework, we can print out a lot of useful error information, such as access routing information, controller information, template information, and database information, etc. Let's take a look at how to print out this information.

3.1 Routing information

In the Laravel framework, we can check which route is currently accessed by printing routing information. The code is as follows:

dd(Route::current());

3.2 Controller information

Sometimes, we need to view the information of the controller being called. In the Laravel framework, we can print the current controller information through the following code:

dd(app('request')->route()->getAction());

3.3 Template information

In the Laravel framework, we can print out the view (template) being used information. Use the following code to print out the information of the view being used:

dd(view()->getFinder()->getHints());

3.4 Database information

In the Laravel framework, we can print out the executed SQL statements and the queried data. The code is as follows:

\DB::listen(function ($query) {
    $sql = $query->sql;
    $bindings = $query->bindings;
    foreach ($bindings as &$binding) {
        $binding = is_numeric($binding) ? $binding : "'" . $binding . "'";
    }
    $sql = str_replace("?", "%s", $sql);
    $sql = sprintf($sql, ...$bindings);
    \Log::info($sql);
});

The above code will print out the SQL code executed in the database, which is convenient for us to view and debug.

4. Summary

In the Laravel framework, printing error messages is a very important part. We can quickly locate and debug code problems by printing information about routes, controllers, templates, and databases. Please note during the development process: Just printing the error message cannot solve the problem, and further analysis and processing are required.

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