如何使用 Doctrine 的 ArrayCollection::exists 方法

Question

I have to check if an Email entity already exists in the ArrayCollection but I have to perform the check on the emails as strings (the Entity contains an ID and some relations to other entites, for this reason I use a separate table that persists all emails).

Now, in the first I wrote this code:

    /**
     * A new Email is adding: check if it already exists.
     *
     * In a normal scenario we should use $this->emails->contains().
     * But it is possible the email comes from the setPrimaryEmail method.
     * In this case, the object is created from scratch and so it is possible it contains a string email that is
     * already present but that is not recognizable as the Email object that contains it is created from scratch.
     *
     * So we hav to compare Email by Email the string value to check if it already exists: if it exists, then we use
     * the already present Email object, instead we can persist the new one securely.
     *
     * @var Email $existentEmail
     */
    foreach ($this->emails as $existentEmail) {
        if ($existentEmail->getEmail()->getEmail() === $email->getEmail()) {
            // If the two email compared as strings are equals, set the passed email as the already existent one.
            $email = $existentEmail;
        }
    }

But reading the ArrayCollection class I seen the method exists that seems to be a more elgant way of doing the same thing I did.

But I don't know how to use it: can someone explain me how to use this method given the code above?

Answer 1

Of course, in PHP a Closure is a simple Anonymous functions . You could rewrite your code as follow:

$exists =  $this->emails->exists(function($key, $element) use ($email){
    return $email->getEmail() === $element->getEmail()->getEmail();
});

Hope this help

Answer 2

Thank you @Matteo!

Just for completeness, this is the code with which I came up:

public function addEmail(Email $email)
{
    $predictate = function($key, $element) use ($email) {
        /** @var  Email $element If the two email compared as strings are equals, return true. */
        return $element->getEmail()->getEmail() === $email->getEmail();
    };

    // Create a new Email object and add it to the collection
    if (false === $this->emails->exists($predictate)) {
        $this->emails->add($email);
    }

    // Anyway set the email for this store
    $email->setForStore($this);

    return $this;
}