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by Christian
263:11
created

DefintionManager::add()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 6

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
dl 0
loc 6
rs 10
c 0
b 0
f 0
cc 1
nc 1
nop 2
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<?php
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declare(strict_types=1);
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/*
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 * (c) Christian Gripp <[email protected]>
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 *
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 * For the full copyright and license information, please view the LICENSE
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 * file that was distributed with this source code.
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 */
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namespace Core23\SitemapBundle\Definition;
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final class DefintionManager implements DefintionManagerInterface
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{
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    /**
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     * Collection of available sitemap definitions.
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     *
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     * @var SitemapDefinitionInterface[]
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     */
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    private $sitemaps;
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    public function __construct()
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    {
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        $this->sitemaps = [];
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    }
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    /**
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     * {@inheritdoc}
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     */
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    public function addDefinition(string $id, array $configuration = []): DefintionManagerInterface
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    {
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        $this->add($id, new SitemapDefinition($id, $configuration));
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        return $this;
0 ignored issues
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Bug Best Practice introduced by core23
The return type of return $this; (Core23\SitemapBundle\Definition\DefintionManager) is incompatible with the return type declared by the interface Core23\SitemapBundle\Def...nterface::addDefinition of type self.

If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.

Let’s take a look at an example:

class Author {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

abstract class Post {
    public function getAuthor() {
        return 'Johannes';
    }
}

class BlogPost extends Post {
    public function getAuthor() {
        return new Author('Johannes');
    }
}

class ForumPost extends Post { /* ... */ }

function my_function(Post $post) {
    echo strtoupper($post->getAuthor());
}

Our function my_function expects a Post object, and outputs the author of the post. The base class Post returns a simple string and outputting a simple string will work just fine. However, the child class BlogPost which is a sub-type of Post instead decided to return an object, and is therefore violating the SOLID principles. If a BlogPost were passed to my_function, PHP would not complain, but ultimately fail when executing the strtoupper call in its body.

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    }
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    /**
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     * {@inheritdoc}
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     */
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    public function getAll(): array
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    {
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        return $this->sitemaps;
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    }
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    /**
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     * @param string                     $code
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     * @param SitemapDefinitionInterface $sitemap
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     *
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     * @return DefintionManagerInterface
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     */
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    private function add(string $code, SitemapDefinitionInterface $sitemap): DefintionManagerInterface
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    {
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        $this->sitemaps[$code] = $sitemap;
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        return $this;
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    }
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}
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