Strange circular dependency in Symfony 5

Question

I am having a problem with Symfony 5 and its Circular Dependency detection mechanism.

I have defined the following class

namespace App\HTSC\Entity\Finance\Subscription;

/**
 * Category
 */
class Category {
    /**
     * @var string
     */
    private $name;

    /**
     * @var integer
     */
    private $version = 1;

    /**
     * @var integer
     */
    private $id;

    /**
     * @var array
     */
    private $fees;

    /**
     * Map of feeType => fee
     * @var array
     */
    private $feeMap = null;
    
    /**
     * Constructor
     */
    public function __construct(Category $category = null)
    {
        if (!is_null($category)) {
            $this->name = $category->name;
            $this->setFees($category->fees);
        } else {
            $this->fees = array();
        }
    }
    
    /**
     * Set name
     *
     * @param string $name
     * @return Category
     * @throws \InvalidArgumentException
     */
    public function setName($name)
    {
        if (is_null($name) || empty($name = trim($name))) {
            return \InvalidArgumentException('Empty category name');
        }
        $this->name = $name;
    
        return $this;
    }

    /**
     * Get name
     *
     * @return string 
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Set version
     *
     * @param integer $version
     * @return Category
     */
    public function setVersion($version)
    {
        $this->version = $version;
    
        return $this;
    }

    /**
     * Get version
     *
     * @return integer 
     */
    public function getVersion()
    {
        return $this->version;
    }

    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    {
        return $this->id;
    }
   
    /**
     * Sets an array of fees to the category.
     * 
     * @param array $fees
     * @return Category
     */
    public function setFees(array $fees) {
        $this->fees = array();
        $this->feeMap = array();
        
        foreach ($fees as $fee) {
            $this->addFee($fee);
        }   
        
        return $this;
    }
    
    /**
     * Add fee to category. Only one fee per fee type allowed. 
     *
     * @param Fee $fee
     * @return Category
     */
    public function addFee(Fee $fee)
    {
        if (!$fee->isValid()) throw new \InvalidArgumentException('Invalid fee added to category');
        
        $feeMap = $this->getFeeMap();
        if (key_exists($fee->getType()->getName(), $feeMap)) {
            throw new \InvalidArgumentException('Multiple fee type [' . $fee->getType()->getName() . '] specified for category [' . $this->name . ']');
        }
        $this->fees[] = $fee;
        $this->feeMap[$fee->getType()->getName()] = $fee;
    
        return $this;
    }

    /**
     * Remove fee
     *
     * @param Fee $fee
     * @return Category
     */
    public function removeFee(Fee $fee)
    {
        $this->fees->removeElement($fee);
        
        return $this;
    }
    
    /**
     * Get fees
     *
     * @return Fee[]
     */
    public function getFees()
    {
        return $this->fees;
    }

    /**
     * Get fee of given type. Returns null if type is not present.
     *
     * @return Fee 
     */
    public function getFee(FeeType $type) 
    {
        $feeMap = $this->getFeeMap();
        if (key_exists($type->getName(), $feeMap)) return $feeMap[$type->getName()];
        return null;
    }
    
    private function getFeeMap() {
        if (is_null($this->feeMap)) {
            $this->feeMap = array();
            foreach ($this->fees as $fee) $this->feeMap[$fee->getType()->getName()] = $fee;
        }
        return $this->feeMap;
    }
    /**
     * Returns whether a category is considered valid.
     * @return boolean
     */
    public function isValid() {
        if (empty($this->name)) return false;
        if (empty($this->fees)) return false;
        return true;
    }
}

When I access the web site and hence my code above, Symfony responds with the following message:

Circular reference detected for service "App\HTSC\Entity\Finance\Subscription\Category", path: "App\HTSC\Entity\Finance\Subscription\Category -> App\HTSC\Entity\Finance\Subscription\Category".

Normally when a circular dependency is detected, a second class is involved; in my case it is a circular dependency between the class itself?

I also inspected other classes using this class, but cannot determine a circular dependency with the this class anywhere.

Anybody experienced the same problem and knows a solution for this?

score 2 · Accepted Answer · answered Aug 24 '20 at 12:53

If that is a model or entity it should not be registered as a service.

Since it is registered as a service then it attempts to set Category service to the Category in the constructor:

public function __construct(Category $category = null)

If you have explicitly registered this as a service in your services.yaml then please unregister it.

If you have not registered it explicitly then please exclude it in your automatic wiring. For example if you have an entry:

    App\:
        resource: '../src/*'
        exclude: '../src/{DependencyInjection,Entity,Migrations,Tests,Kernel.php}'

then be sure to add the folder which holds your class to the exclude value.

Please note that "normal" (root level) Entities are also excluded here.

Hi Bartosz. Thanks, that helped. I added the subtree in which these classes reside to the exclude value in services.yaml, which solved the problem. — hatemp, Aug 24 '20 at 13:13

Strange circular dependency in Symfony 5

1 Answers1