Looking for more information on how to do PHP the right way? Check out PHP: The Right Way

Rob Allen:
Implementing CORS in Zend Expressive
Nov 15, 2017 @ 09:20:13

In a new post to his site Rob Allen shows you how to implement CORS in a Zend Expressive application through the use of a simple middleware wrapper that sends the appropriate headers.

On a recent project, I needed to implement CORS support for my Expressive API. The easiest way to do this is to use Mike Tuupola's PSR-7 CORS Middleware.

As this is a standard Slim-Style PSR-7 middleware implementation, we need to wrap it for Expressive, so we make a factory. [...] We then register this in our AppConfigProvider::getDependencies() by adding to the factories key.

He includes the code and configuration changes required to make it all work and includes example output of a request (with headers) from a curl call to the API. He also includes a section on working with JSON error responses and ProblemDetails for when there are issues related to the current CORS policy definition.

tagged: cors tutorial zendexpressive middleware json error problemdetails

Link: https://akrabat.com/implementing-tuupola-cors-in-expressive/

Rob Allen:
Customising Whoops in Expressive
Nov 08, 2017 @ 09:53:40

Rob Allen has a new post to his site showing how you can customize the Whoops output in a Zend Expressive application. Whoops is a package that provides more well-structured and more attractive error output when an issue comes up.

I find the Whoops error handler page in Expressive quite hard to read and particularly dislike that the error message displayed in the top left is hidden if it's more than a few words long.

To fix this, I discovered that you can provide a custom CSS file to the PrettyPrintHandler and then override to your heart's content! One way to do this is to add a delegator factory to add the additional functionality, so let's do that.

He then includes the configuration changes you'll need to make in the Expressive setup to have it recognize the factory and be able to use it as a dependency. He then includes the code to create the factory itself, adding a path to the local CSS files and pushing the custom whoops.css file into the page handler. Example CSS is included showing an update to the display of the main message, removing the need for a mouseover to view it.

tagged: zendexpressive zendframework whoops error handler css configuration factory tutorial

Link: https://akrabat.com/customising-whoops-in-expressive/

Sergey Zhuk:
Building ReactPHP Memached Client: Errors And Connection Handling
Oct 27, 2017 @ 09:21:56

Sergey Zhuk has posted the second part of his series covering the creation of a ReactPHP-based memcached client for asynchronous cache handling. In part one he set up some of the basic structure of the client and got it to a working state. In this latest part he expands on that base and improved the error and connection handling to make it more robust.

In the previous article, we have created a simple streaming Memcached client for ReactPHP ecosystem. It can connect to Memcached server, execute commands and asynchronously return results. In this article we are going to implement some improvements: connection handling [and] errors handling.

He then goes through and makes changes to allow for correct handling of the connection closing where it can either be closed by an option you specify or a forced close from the server. On the error handling side he shows how to handle invalid commands (throwing a WrongCommandException) and a failed command, such as when the value couldn't be stored for one reason or another.

tagged: reactphp memcached client async error connection handling series part2

Link: http://seregazhuk.github.io/2017/10/14/memcached-reactphp-p2/

Sebastian De Deyne:
Debugging the dreaded "Class log does not exist" error in Laravel
Oct 26, 2017 @ 09:57:03

Sebastian De Deyne has a post to his site that shares some hints on how to track down the dreaded "class log does not exist" error in Laravel-based applications.

Every now and then I come across a Class log does not exist exception in Laravel. This particular exception is thrown when something goes wrong really early in the application, before the exception handler is instantiated.

Whenever I come across this issue I'm stumped. Mostly it's related to an invalid configuration issue or an early service provider that throws an exception. I always forget how to debug this, so it's time to document my solution for tracking down the underlying error.

As Laravel hides the real issue behind an error thrown from the logging class, it's difficult to determine where the problem actually lies. The path to solve this and get to the actual error involves a change to the handle method and using the die method to output both the message and stack trace of the issue before Laravel can try to handle it. Obviously this is only really meant for debugging but can be handy when this error is hiding the real reason for the failure.

tagged: laravel error message exception logger classlog exist tutorial

Link: https://sebastiandedeyne.com/posts/2017/debugging-the-dreaded-class-log-does-not-exist-error-in-laravel

Rob Allen:
Displaying errors in Expressive with Twig
Oct 19, 2017 @ 12:47:36

Rob Allen has a quick post for the Twig and Zend Expressive users out there showing how to display errors if you're not using the Whoops error handler.

If you're not using the Whoops error handler with Expressive and are using the Twig renderer, then you are given no information about the problem that occurred, even in debug mode.

He includes the Twig template to output the error message and, if the application is in "debug" mode, show an optional block of extra information. This provides details about the exception thrown and some of the previous errors. The previous errors are looped about output to provide more context around the failure.

tagged: error twig zend zendexpressive tutorial output debug

Link: https://akrabat.com/displaying-errors-in-expressive-with-twig/

Asmir Mustafic:
How to add custom error codes to your Symfony API responses
Sep 22, 2017 @ 11:10:01

Asmir Mustafic has posted a guide on his site showing how to create custom error codes in the API responses from your Symfony-based application.

When writing APIs, a proper error handling is fundamental. HTTP status codes are a great start, but often when we deal with user inputs is not enough. If out model has complex validation rules, understanding the reason behind an 400 Bad Request error can be not trivial.

Fortunately when for symfony developers there are many libraries to deal with it. Symfony Validator, <a href="https://github.com/symfony/form>Symfony Form, <a href="https://github.com/FriendsOfSymfony/FOSRestBundle>FOS REST Bundle and JMS Serializer combined allows you to have nice error messages to be shown to your users.

He walks you through the code required to create the default error handling with an "author" example. This includes the creation of the entity as well as the form and controller to handle the request/response. He then refactors this away from the default to create the custom error handler with handlers for the message and code to be returned. The post ends with the configuration changes to register it with the application and what the result ends up looking like.

tagged: symfony tutorial custom error code api example

Link: http://www.goetas.com/blog/how-to-add-custom-error-codes-to-your-symfony-api-responses/

thePHP.cc:
Don't call instance methods statically
Jul 25, 2017 @ 11:16:39

In this new post on thePHP.cc site they talk about calling instance methods statically, more specifically that it should be avoided.

There are quite a few things in PHP 4 that were a bit strange. One example is that PHP 4 allowed static calling of instance methods. [...] To keep backwards compatibility with PHP 4, this code works up to PHP 5, even though [the method in the example[ is not declared static.

[...] Now things will get really weird. When calling an instance method of another class statically, the $this context would carry over from the caller to the called class. In other words, $this suddenly refers to another object instance. While in PHP 5, this used to be an E_STRICT error, PHP 7 will emit an E_DEPRECATED error.

They point out that, while this is definitely odd behavior that shouldn't exist, it hasn't been removed because of PHP's backwards compatibility principles and only removing functionality like this in major versions. So, instead, they recommend calling all non-static methods using an instance of the class injected rather than directly calling them.

tagged: instance method call static object avoid error

Link: https://thephp.cc/news/2017/07/dont-call-instance-methods-statically

Laravel News:
A guide for prioritizing application errors
Jul 03, 2017 @ 10:17:26

The Laravel News site has posted a tutorial that offers some advice on how to prioritize fixing bugs and errors in your applications.

One major problem is that prioritizing errors isn’t always clear. Figuring out how much negative impact a bug is really causing is important to answer because not all bugs are worth fixing.

That’s why having a solid workflow in place for prioritizing bugs is so important. In order to confidently allocate your engineering resources on bug fixes and feature building, you need to understand the scope of each application error, and its impact on your customers. Then you can definitively say particular bugs are high enough priority that they should be scheduled into a sprint alongside your work on building new features.

The article is then broken down into a few different sections, each with a few points underneath:

  • Get setup with smart error reporting from the start
  • Focus your error inbox to keep it actionable
  • Prioritize the most relevant errors first
  • Prioritize errors by moving them into your debugging workflow

The post is sponsored by Bugsnag so there's some of the content that suggests using their service but the advice is sound for any kind of error handling workflow.

tagged: priority error tracking application fixes workflow tips

Link: https://laravel-news.com/prioritize-application-errors

Laravel News:
Laravel 5.5 Gets Improvements with the Default Error Views
May 05, 2017 @ 10:55:31

On the Laravel News site there's a recent post showing a feature coming in version 5.5 of the framework that will help make creating error views easier:

Coming in Laravel 5.5 is a new and improved design for the error pages. The default errors will extend from an errors::layout file and get some small design additions over the current style with flexbox and a vertically centered message.

They compare the older version to the newer, cleaner one and how you can still, even in 5.5, have your own custom error pages named based on the HTTP error code (like 500.blade.php or 403.blade.php). They end the post covering the renderHttpException and how it determines which of the error templates to use.

tagged: laravel error template v55 update customize blade tutorial

Link: https://laravel-news.com/laravel-5-5-error-views

Hackermoon.com:
Debugging a PHP application with strace
Mar 28, 2017 @ 11:24:43

On the Hackernoon.com site there's a recent post from Paolo Agostinetto showing you how to debug your PHP application with a different tool that most might use: strace.

Every once in a while it happens that you have a tricky bug, and when it does you risk to lose hours or even days fixing it.

[...] Yet, sometimes there is that one bug that makes you lose your shit after a whole afternoon spent looking for the root cause. In my experience, bugs that I introduce are generally very quick and easy to spot and fix. But the real challenge is finding bugs in other people’s code like third party libraries, PHP extensions or even PHP itself.

He then talks about a time when his situation was a bit different - he was getting 500 errors from his code that weren't being caught correctly by error handling. He found that Apache was out-of-memory-ing but debugging the exact cause (a suspect Doctrine query) would take more time. Instead he turned to strace and, with a bit of hunting in the resulting output, he tracked the issue down to XDebug being enabled (and a setting that was generating a memory leak).

tagged: debug application strace memory error xdebug process

Link: https://hackernoon.com/debugging-a-php-application-with-strace-4d0ae59f880b