Hidden Gems of PHP Packages: Symfony\Finder and SplFileInfo

2018-08-13

Why I Use it?

1. Do you work with files in 5 different places in your application in a single way and you miss consistent naming?

   <?php declare(strict_types=1);
   
   function processFile(string $file) {
        // is absolute?
        // relative to what?
   }
   
   function processFile(string $fileAbsolute) {}
   function processFile(string $filePath) {}
   function processFile(string $absoluteFile) {}
   function processFile(string $relativePath) {}
   function processFile(string $filename) {}
   

2. Do you need to test file paths on various CI machines?

   Expected test string didn't match:
   -Error was found in: /home/im-very-cool-guy/my-website/www/my-home-porn-web/public/index.php
   +Error was found in: /travic-ci/travis-directory-for-this-web/public/index.php
   

3. Do you want to report the user the relative path instead of hard to read absolute one?

   -Error was found in: /home/im-very-cool-guy/my-website/www/my-home-porn-web/public/index.php
   +Error was found in: public/index.php
   

4. Do you want to forget all those file_* functions and just work with the file instead?

   <?php declare(strict_types=1);
   
   file_exists($file);
   is_file($file);
   is_directory($file); // actually: is_dir($file);
   is_readable($file);
   is_absolute($file); // well, you have to create this one yourself, and don't forget the Windows and Linux differences!
   

Thanks to Symfony\Finder and its custom SplFileInfo I can be lazy, use object API and work safer and faster in all these cases above and more. Actually, I started to using SplFileInfo over stringly file paths/names after too many bugs appeared in my code and I'm happier and more relaxed ever since.

What is splFileInfo? It's native object in PHP - like DateTime - that wraps the file and provides nice object API for it. The Symfony\Finder package adds 3 extra methods that make work with files just a bit smoother. They go very well together since the package creates all the splFileInfo instances for you.

How to Install

composer require symfony/finder

How I Use it

We'll find all available feature in the documentation, but basic usage it like this:

<?php declare(strict_types=1);

use Symfony\Component\Finder\Finder;

$finder = Finder::create()
    ->files()
    ->in(__DIR__)
    ->name('composer.json')
    ->getIterator();

foreach ($finder as $splFileInfo) {
    var_dump($splFileInfo); // instance of "Symfony\Component\Finder\SplFileInfo"
}

Symfony\Component\Finder\Finder

name()

This method accepts also regular expressions. Do you want to find all YAML files?

<?php declare(strict_types=1);

use Symfony\Component\Finder\Finder;

$finder = Finder::create();
$finder->name('#\.(yaml|yml)$#');

append()

Do you want to add just a single file that finder criteria would not find? Normally, you'd have to create SplFileInfo manually, think of relative/absolute paths etc. So much work. Instead, you can just append it and Finder will add it for you.

<?php declare(strict_types=1);

use Symfony\Component\Finder\Finder;

return Finder::create()
    ->name('#\.php$#')
    ->in(__DIR__ . '/Source')
    ->append([__DIR__ . '/Source/SomeClass.twig']);

notPath() or exclude()

It's common and bad practice to put tests files into /src. It's historical reason mostly, but we still have to deal with that. You don't want to work with 3rd party code tests, right?

<?php declare(strict_types=1);

use Symfony\Component\Finder\Finder;

$finder = Finder::create()
    // directories
    ->exclude('spec')
    ->exclude('test')
    ->exclude('Tests')
    ->exclude('tests')
    ->exclude('Behat')
    ->name('*.php');

// or match path name
$finder->notPath('#tests#');

Symfony\Component\Finder\SplFileInfo

getRelativePath()

Let's get back to the composer.json example above (from in MonorepoBuilder). This is how we get relative directory:

<?php declare(strict_types=1);

/** @var \Symfony\Component\Finder\SplFileInfo $splFileInfo */
$splFileInfo->getRelativePath(); // "/"

getRelativePathname()

This method is bit different - it returns relative filename:

<?php declare(strict_types=1);

/** @var \Symfony\Component\Finder\SplFileInfo $splFileInfo */
$splFileInfo->getRelativePath(); // "composer.json"

This is very handy for output reporting in PHP CLI Apps like ECS, PHP CS Fixer, PHP_CodeSniffer or PHPStan. Compare yourself - the computer absolute scope:

An error was found in /home/im-very-cool-guy/my-website/www/my-home-porn-web/public/index.php

and human relative scope:

An error was found in public/index.php

Honorable Mentions

There are few more methods that I use from time to time:

<?php declare(strict_types=1);

/** @var \Symfony\Component\Finder\SplFileInfo $splFileInfo */
$splFileInfo->getRealPath();
// absolute path - returns "/var/www/this-post/composer.json"

$splFileInfo->getContents();
// gets the content of file with error propagated to an exception - very nice!

$splFileInfo->getBasename('.' . $splFileInfo->getExtension());
// returns "composer"

Do you like it? Go and give Symfony\Finder or at least SplFileInfo a try.

Happy coding!

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