PHP Tips and tricks

In 2014, I created a PHP version of the Munin plugins for Beanstalkd introduced by AirBnB, but originally created in Python.

Fast forward four years, and after being adapted for compliances with the PHP-FIG PSR1, PSR2 and PSR12 standards, as well as the Zend coding standards, and with extra documentation, I published the first "stable" version 1.0.0 of the package today under the Apache APL-2.0 license.

The problem: XDebug doesn't work for Composer scripts

PhpStorm is quite convenient to debug scripts with XDebug (do you support Derick for giving us XDebug ?): just add a "Run/Debug configuration", choosing the "PHP Script" type, give a few parameters, and you can start debugging your PHP CLI scripts, using breakpoints, evaluations, etc.

Wonderful. So now, let's define such a configuration to debug a Composer script, say a Behat configuration generator from site settings for some current Drupal 8 project. Apply the configuration, run it in debug mode, and ....

...PhpStorm doesn't stop, the script runs and ends, and all breakpoints were ignored. How to actually use breakpoints in the IDE ?

In most cases, call_user_func() and call_user_func_array() are just slower but more flexible ways to call functions or methods. But it turns out they are not entirely equivalent where methods are involved. Consider this fragment, and guess the output.

The problem: routing /blogs, not just /blogs/ in Silex

Route mounting in the Silex PHP framework allows conveniently grouping controllers per feature in separate files, then using mounting them on some prefix path like $app->mount('/blogs'). This will prepend the prefix "/blogs" to the paths defined in the the feature controller, effectively delegating to it all the /blogs/* routes. However, as the Silex documentation claims:

When mounting a route collection under /blog, it is not possible to define a route for the /blog URL. The shortest possible URL is /blog/.

This means handling the route mount point has to be done by a route outside the mounted feature, which makes it slightly less clean, as you have to do something like:

<?php$blog = require_once __DIR__ . '/controllers-blog.php';// This will handle /blogs/ and below, but not /blogs$app->mount('/blogs', $blog);// So we have to use a non-mounted route from a sub-request to avoid a redirect().$app->get('/blogs', function () use($app) {   // forward to /blogs/   $subRequest = Request::create('/blogs/' , 'GET');   return $app->handle($subRequest , HttpKernelInterface::SUB_REQUEST);}?>

But is there really no workaround for this limitation ? Sure there is!

The problem: packages.drupal.org broken

I was starting my weekly work for the Drupal GraphQL module by the customary composer update --prefer-source -vvv command, ready to watch composer spit out some hundred lines sipping my coffee, but this time something turned out to be wrong:

  [...snip...]
Downloading https://packages.drupal.org/8/drupal/provider-2016-4%24a30289dd8394e5271bd77777bb14b361c5938656f1cddad7fae1c00d5d6ba9c6.json

  [Composer\Downloader\TransportException]
  The "https://packages.drupal.org/8/drupal/provider-2016-4%24a30289dd8394e5271bd77777bb14b361c5938656f1cddad7fae1c00d5d6ba9c6.json" file could not be downloaded (HTTP/1.1 404 Not Found)
  [...snip...]

OK, so packages.drupal.org is down for now. How can we work around this ?

The mystery

There are a number of issues on StackOverflow and elsewhere about the problems met when upgrading to PHP 7, so when I upgraded a Debian Wheezy server this week, I only upgraded to Jessie with its standard 5.6 version, not expecting problems. But of course, there had to be this mystifying error which seems to be most often associated with PHP 7.0 : like Debian bug 709302:

[Wed May 22 14:20:26 2013] [error] [client 127.0.0.1] PHP Fatal error: require_once(): Failed opening required './libraries/php-gettext/gettext.inc' (include_path='.') in /usr/share/phpmyadmin/libraries/select_lang.lib.php on line 389
[Wed May 22 14:20:26 2013] [error] [client 127.0.0.1] PHP Fatal error: /require_once(): Failed opening required /'./libraries/php-gettext/gettext.inc' (include_path='.') in //usr/share/phpmyadmin/libraries/select_lang.lib.php on line 389
[Wed May 22 14:20:26 2013] [error] [client 127.0.0.1] PHP Fatal error: require_once(): Failed opening required './libraries/php-gettext/gettext.inc' (include_path='.') in /usr/share/phpmyadmin/libraries/select_lang.lib.php on line 389

So how do we fix this for 5.6 ?

One nice thing during Drupal 7/8 development is the ability, thanks to the devel module, to get a list of all SQL queries ran on a page. As I've been working quite a bit on MongoDB in PHP recently, I wondered how to obtain comparable results when using MongoDB in PHP projects. Looking at the D7 implementation, the magic happens in the Database class:

<?php// Start logging on the default database.define(DB_CHANNEL, 'my_logging_channel');\Database::startLog(DB_CHANNEL);// Get the log contents, typically in a shutdown handler.$log = \Database::getLog(DB_CHANNEL);?>

With DBTNG, that's all it takes, and devel puts it to good use UI-wise. So is there be an equivalent mechanism in MongoDB ? Of course there is !

While porting (well, actually rewriting) an old PHP library to Go, I had to use a CRC (cyclic redundancy check) on a buffer. In old-school PHP, the standard is well established since PHP 4: just use crc32 from the strings package, and beware of the sign bit or, to be a bit more current while still compatible, use the hash() function from the hash package, like this example:

Call a method on a nil pointer (null object) ? This is a classical bug. What if it somehow turned out to be a valid and useful construct in some languages, say in Go ? And what about PHP ?

Doctrine Annotations is a central part of the Drupal 8 Plugin API. One of its conceptual annoyances is the need for a separate autoloading process for annotations, which in some scenarios leads to duplicated path declarations. Let us see how to remedy to it.