Symfony 2 This form should not contain extra fields - forms

Question

I created a form using formBuilder in Symfony. I add some basic styling to the form inputs using an external stylesheet and referencing the tag id. The form renders correctly and processes information correctly.
However, it outputs an unwanted unordered list with a list item containing the following text: This form should not contain extra fields.
I am having a really hard time getting rid of this notice. I was wondering if someone can help me understand why it being rendered with my form and how to remove it?
Many thanks in advance!
Controller
$form = $this->createFormBuilder($search)
->add('searchinput', 'text', array('label'=>false, 'required' =>false))
->add('search', 'submit')
->getForm();
$form->handleRequest($request);
Twig Output (form is outputted and processed correctly
This form should not contain extra fields.
Rendered HTML
<form method="post" action="">
<div id="form">
<ul>
<li>This form should not contain extra fields.</li>
</ul>
<div>
<input type="text" id="form_searchinput" name="form[searchinput]" />
</div>
<div>
<button type="submit" id="form_search" name="form[search]">Search</button>
</div>
<input type="hidden" id="form__token" name="form[_token]" value="bb342d7ef928e984713d8cf3eda9a63440f973f2" />
</div>
</form>

Answer 1

It seems to me that you have the problem because of the token field. If it is so, try to add options to createFormBuilder():
$this->createFormBuilder($search, array(
'csrf_protection' => true,
'csrf_field_name' => '_token',
))
->add('searchinput', 'text', array('label'=>false, 'required' =>false))
->add('search', 'submit')
->getForm();
To find out the extra field use this code in controller, where you get the request:
$data = $request->request->all();
print("REQUEST DATA<br/>");
foreach ($data as $k => $d) {
print("$k: <pre>"); print_r($d); print("</pre>");
}
$children = $form->all();
print("<br/>FORM CHILDREN<br/>");
foreach ($children as $ch) {
print($ch->getName() . "<br/>");
}
$data = array_diff_key($data, $children);
//$data contains now extra fields
print("<br/>DIFF DATA<br/>");
foreach ($data as $k => $d) {
print("$k: <pre>"); print_r($d); print("</pre>");
}
$form->bind($data);

Answer 2

This message is also possible if you added/changed fields in your createFormBuilder() and press refresh in your browser...
In this case it's ok after sending the form again ;-)

Answer 3

I got the same message while having multiple forms on the same page. Turns out, symfony defaults to the name 'form' for all of them. Instead of using createFormBuilder, you can change the name of the form to avoid conflicts using
public FormBuilderInterface createNamedBuilder(string $name, string|FormTypeInterface $type = 'form', mixed $data = null, array $options = array(), FormBuilderInterface $parent = null)
See https://stackoverflow.com/a/13366086/1025437 for an example.

Answer 4

I ran into this error when creating a multi-step form.
When the step 1 form is submitted, $request->request contains acme_mybundle_myform array. This created a validation error and stopped the back, forward and form fields from populating correctly. Not to mention "this-form-should-not-contain-extra-fields"
I discovered this thanks to the code by nni6.
The solution in my case was inside the controller:
if ($form->isValid())
{
if($form->has('nextStep') && $form->get('nextStep')->isClicked())
{
$session->getFlashBag()->set('notice', 'Next clicked');
$registerType->incrementStep();
$request->request->remove('acme_mybundle_myform');
return $this->forward("AcmeMyBundle:Default:register", array($request));
}
....
}

Answer 5

I had the same error.
It was because I had a form which, by mistake, had a NULL name.
In the HTML, the name attribute would look like this:
<form name href="..." action"..."></form>
As simple as that.
Might not be the case for everyone, but worth to check.