Leveraging Custom Field Options

I am getting an error: Function name must be a string
It highlights this: $user = $callback($this->userRepository, $value);

Hey @Farry7

Have you applied all code changes from this chapter before testing it?

Cheers!

What if you want to show the name of the user instead of the e-mail address but still want to use the email property of the user to do the transformation?

Hey Dirk !

Hmm... interesting question :). Ultimately, you need the "email" (or even "user id") to be what is submitted to the server so that the form system can reliably look up that User using a unique key (the email or "user id"). So if you want to display the "name of the user" instead of the email, this is really more of a "rendering trick". What I mean is, under the surface, your form field should still work 100% with an email address, because this is what needs to be submitted.

So, there are two pieces to this:

A) How do I create an input field where the "email" is what is actually submitted (i.e. the value= attribute is set to the email) but the "name of the user" is what's actually displayed/visible.

B) How do I make the auto-complete system play with this special text box.

As far as I can tell, you'll need to do a little bit of custom setup to get this all working with the auto-complete system. On the surface, part (A) is a fairly-straightforward JavaScript trick: you render a completely normal input text box... except that maybe you add a data-name attribute which is set to the "name of the user". Then, on page load, you use JavaScript to "hide" that text box completely and create a new text box right next to it (or even just a "div" that looks like a text box) where the value="" the "name of the user". The second text box would not have a "name=" attribute, and so would not be submitted to the server. It's just there as a visual "trick".

Then, you would probably need to hook into a custom autocomplete event - https://github.com/algolia/autocomplete.js#events - probably autocomplete:selected - to that part working. In theory, if you "attach" the autocomplete to the "real input field" (the one that you hid), most things will just work. What I mean is: when the user selects someone from the auto-complete, it will update the "value" attribute of the hidden input box. The only possible problem here is positioning: I'm not sure if autocomplete will get confused about where to position the autocomplete because the input his hidden. The other thing you will need to do (just to make everything "look" correct) would be to update the visible input box with the "name of user".

There might be a JavaScript library that will combine these two abilities better than then one we're using, I'm not sure. At the end of the day, the "server form side" stuff is pretty simply - it's all a big, elaborate JavaScript trick.

Let me know if that helps :).

Cheers!

Cannot autowire service "App\Form\Transformer\SpecialtyToArrayTransformer": argument "$finderCallback" of method "__construct()" is type-hinted "callable", you should configure its value explicitly.
In Symfony 5, autowiring does not work. What to do?

Hey Ozornick!

Sorry for the slow reply! I think I know what's going on. Due to the way that transformers work in Symfony, you need to instantiate these objects manually. That's what we do here: https://symfonycasts.com/screencast/symfony-forms/custom-field-option#codeblock-71e9a67f67

Do you, by chance, have a constructor argument on one of your services that is type-hinted with SpecialtyToArrayTransformer? It looks to me like Symfony is seeing a constructor argument type-hinted with this class and is then trying to autowire & instantiate the SpecialtyToArrayTransformer, which is not what we want. We want to instantiate this manually so that we can pass the callback argument.

Let me know if that helps :).

Cheers!

I am overhelmed with the passing of a vatriable $email to the OptionsResolver:

    public function configureOptions(OptionsResolver $resolver)
    {
            $resolver->setDefaults([
            'invalid_message' => 'Hmm, user not found!',
            'finder_callback' => function(UserRepository $userRepository, string $email) {
                return $userRepository->findOneBy(['email' => $email]);
            }            
        ])

How is the variable passt through and how it comes?

I tried to build the form field 'comments' in ArticleFormType.php using query_builder like this,

->add('comments', EntityType::class, array(
                'placeholder' => 'choose comments',
                'multiple' => true,
                'invalid_message' => 'Symfony is too smart for your hacking!',
                'class' => Comment::class, 
                'query_builder' => function (CommentRepository $er)  use ($options) {
                    return $er->getWithSearchQueryBuilder($options['comment_param']); 
                },
            ))

but I could not pass the parameter to narrow my CommentRepository.
Any idea on this?

Hey pete,

That's PHP anonymous function, and the 2nd example perfectly shows how to pass variables to it - you need to add "use ()", here's an example:

public function configureOptions(OptionsResolver $resolver)
{
    $email = 'test@example.com';

    $resolver->setDefaults([
        'invalid_message' => 'Hmm, user not found!',
        'finder_callback' => function (UserRepository $userRepository) use (string $email) {
            return $userRepository->findOneBy(['email' => $email]);
        }            
    ])
}

Please, read PHP docs about using anonymous functions here to understand it better: https://www.php.net/manual/en/functions.anonymous.php

Cheers!

Thanks Victor, I got the passing variable through the anonymous function with the use. The confusing part was for me, how the value shoud be passed from controller into buildForm function of the ArticleFormType. I overseen tha part, of option parameter defined in configureOptions() but passed in the method createForm as third parameter in Controller. You clarified this part in one of the following tutorial. Thanks for a great learning material!

Hey Pete,

Ah, I see... Glad you figured that out!

Cheers!

Hi, Please can use the callable argument in symfony 3.4 ? because i don't have autocompletion in the __construct function
thanks

Hey Alain N.

The callable type-hint doesn't come from Symfony, it comes from PHP (since PHP5.4 http://php.net/manual/en/language.types.callable.php ). In other words, yes, you should be able to use it.

Cheers!

Hi, by adding the callback mechanics to my code, I lost the mechanics of NotNull on the author, the callBack necessarily expects a string in second argument, and if I don't provide any author to my form, an exception is thrown. Thank you.

I changed the signature of the callable with string $email = null, however it is the invalid_message that is returned instead of the NotNull message, an idea?

Hey gabrielmustiere

About the $email, good catch, you have to allow passing nulls in order to avoid errors. And about the wrong constraint message, I'm not totally sure, I would need to see your code but first try adding this into your Article class

class Author 
{
...
    /**
     * @ORM\ManyToOne(targetEntity="App\Entity\User", inversedBy="articles")
     * @ORM\JoinColumn(nullable=false)
     * @Assert\NotNull(message="Please set an author")
     * @Assert\Valid() # Add this line
     */
    private $author;
...
}

Cheers!

Hi MolloKhan , thanks for the reply, i added the Valid Assert, same message is returned :/
You can find my code here

I just sent you a PR! (BTW, I didn't try the code but I'm 99% sure it will fix it)

Thank you, the good exception is thrown in.

What was the solution?

Hey @Mike

Here is the solution ;) https://github.com/gabrielm...