Get all errors along with fields the error is connected to

Question

I'm using Symfony2 forms to validate POST and PUT requests to an API. The form handles binding the request data to the underlying entity and then validating the entity. Everything is working pretty well except for collecting errors. I'm using the FOSRestBundle and am throwing a Symfony\Component\HttpKernel\Exception\HttpException with a 400 status code and a message containing the form error messages if validation fails. The FOSRestBundle handles converting this into a JSON response. The controller method I have to perform all of this looks like the following (all fields bubble their errors up to the form):

protected function validateEntity(AbstractType $type, $entity, Request $request)
{
    $form = $this->createForm($type, $entity);
    $form->bind($request);
    if (! $form->isValid()) {
        $message = ['Invalid parameters passed.'];
        foreach ($form->getErrors() as $error) {
            $message[] = $error->getMessage();
        }
        throw new HttpException(Codes::HTTP_BAD_REQUEST, implode("\n", $message));
    }
}

The problem I have is that when I collect the form level errors through $form->getErrors() I can only access the error message and not the name of the field that the error is connected to. This is a particular problem when a POST or PUT parameter corresponds to an id for a related entity. If an invalid value is submitted the error messages for that is simply 'This value is not valid', which is not very good in this context. Ideally I'd like to do either of the following:

• For each error get hold of the field name it's connected to so that I can format the message something like "fieldname: error message"
• If that's not possible is it possible to customise the error message for an invalid entity type so that something better than 'This value is not valid' is displayed?

Answer 1

You can take getErrorsAsString method as an example to get the functionality you want. Also you have to set invalid_message option on the form field to change This value is invalid message.

Answer 2

and for symfony >= 2.2

private function getErrorMessages(\Symfony\Component\Form\Form $form) {
    $errors = array();
    foreach ($form->getErrors() as $key => $error) {
        $template = $error->getMessageTemplate();
        $parameters = $error->getMessageParameters();

        foreach ($parameters as $var => $value) {
            $template = str_replace($var, $value, $template);
        }

        $errors[$key] = $template;
    }
    if ($form->count()) {
        foreach ($form as $child) {
            if (!$child->isValid()) {
                $errors[$child->getName()] = $this->getErrorMessages($child);
            }
        }
    }
    return $errors;
}

Answer 3

Use this function to get all error messages after binding form.

private function getErrorMessages(\Symfony\Component\Form\Form $form) {
    $errors = array();
    foreach ($form->getErrors() as $key => $error) {
        $template = $error->getMessageTemplate();
        $parameters = $error->getMessageParameters();

        foreach($parameters as $var => $value){
            $template = str_replace($var, $value, $template);
        }

        $errors[$key] = $template;
    }
    if ($form->hasChildren()) {
        foreach ($form->getChildren() as $child) {
            if (!$child->isValid()) {
                $errors[$child->getName()] = $this->getErrorMessages($child);
            }
        }
    }
    return $errors;
}

Answer 4

I created a bundle to help with this issue.

You can get it here:

https://github.com/Ex3v/FormErrorsBundle

Contributions are welcome. Cheers.

Answer 5

I needed a solution to get an associative array of all errors of all nested forms with the key formated so it represents the document id of the corresponding form field element:

namespace Services;

use Symfony\Component\Form\Form;
use Symfony\Component\Form\FormErrorIterator;

/**
 * Class for converting forms.
 */
class FormConverter
{
    /**
     * Gets all errors of a form as an associative array with keys representing the dom id of the form element.
     *
     * @param Form $form
     * @param bool $deep Whether to include errors of child forms as well
     * @return array
     */
    public function errorsToArray(Form $form, $deep = false) {
        return $this->getErrors($form, $deep);
    }

    /**
     * @param Form $form
     * @param bool $deep
     * @param Form|null $parentForm
     * @return array
     */
    private function getErrors(Form $form, $deep = false, Form $parentForm = null) {
        $errors = [];

        if ($deep) {
            foreach ($form as $child) {
                if ($child->isSubmitted() && $child->isValid()) {
                    continue;
                }

                $iterator = $child->getErrors(true, false);

                if (0 === count($iterator)) {
                    continue;
                } elseif ($iterator->hasChildren()) {
                    $childErrors = $this->getErrors($iterator->getChildren()->getForm(), true, $child);
                    foreach ($childErrors as $key => $childError) {
                        $errors[$form->getName() . '_' . $child->getName() . '_' .$key] = $childError;
                    }
                } else {
                    foreach ($iterator as $error) {
                        $errors[$form->getName() . '_' . $child->getName()][] = $error->getMessage();
                    }
                }
            }
        } else {
            $errorMessages = $this->getErrorMessages($form->getErrors(false));
            if (count($errorMessages) > 0) {
                $formName = $parentForm instanceof Form ? $parentForm->getName() . '_' . $form->getName() : $form->getName();
                $errors[$formName] = $errorMessages;
            }
        }

        return $errors;
    }

    /**
     * @param FormErrorIterator $formErrors
     * @return array
     */
    private function getErrorMessages(FormErrorIterator $formErrors) {
        $errorMessages = [];
        foreach ($formErrors as $formError) {
            $errorMessages[] = $formError->getMessage();
        }

        return $errorMessages;
    }
}

Answer 6

Tried everything, nothing worked as I wanted.
Here is my attempt with Symfony 4 (also why the hell isn't this available by default in the framework is beyond me, it's like they dont want us to use forms with ajax :thinking:)

It returns a messages array, with the keys being the dom id as it would be generated by Symfony (it works with arrays as well)

//file FormErrorsSerializer.php
<?php

namespace App\Helper;

use Symfony\Component\Form\Form;
use Symfony\Component\Form\FormError;
use Symfony\Component\Form\FormErrorIterator;

class FormErrorsSerializer
{
    public function getFormErrors(Form $form): array
    {
        return $this->recursiveFormErrors($form->getErrors(true, false), [$form->getName()]);
    }

    private function recursiveFormErrors(FormErrorIterator $formErrors, array $prefixes): array
    {
        $errors = [];

        foreach ($formErrors as $formError) {
            if ($formError instanceof FormErrorIterator) {
                $errors = array_merge($errors, $this->recursiveFormErrors($formError, array_merge($prefixes, [$formError->getForm()->getName()])));
            } elseif ($formError instanceof FormError) {
                $errors[implode('_', $prefixes)][] = $formError->getMessage();
            }
        }

        return $errors;
    }
}