Display Twig Form with a loop - forms

Question

I'm currently working on a private social network for fun and to improve my skills.
Anyway, I want to display a form to leave a comment on a post using a loop but I have issues trying that.
I'm using Symfony, twig and bootstrap, and I'd like to keep js, jquery or ajax away.
Here is my code:
My form builder:
class CommentType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('title', null, [
"label" => "Your title"
])
->add('content', null, [
"label" => "Your content"
])
->add('submit', SubmitType::class, [
"label" => "Publish your shitty comment!"
]);
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => Comment::class,
]);
}
}
and my view:
<ul class="nav col-4 offset-3">
{% for post in posts %}
<li class="postItem">
<article class="postItem">
<p> {{ post.title }} </p>
<img id="postPics" src="{{ asset('./pictures/posts/' ~ post.picture) }}">
{{ form(leaveCommentForm) }}
<h3>{{ post.title }}</h3>
<p>{{ post.content }}</p>
<author>{{ post.user.username }}</author>
<div class="commentPost">
{% for comment in post.comments %}
<article>
<h6 style="font-weight: bold">{{ comment.title }} -
By
<author>{{ comment.user.username }}
on {{ comment.dateCreated | date('Y-M-d') }}</author>
</h6>
<p>{{ comment.content }}</p>
</article>
{% endfor %}
</div>
<input type="hidden" value="{{ post.id }}" name="postId"> {{ post.id }}
<button class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal">
Leave a comment
</button>
<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel"
aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<h4 class="modal-title" id="myModalLabel">Leave a comment</h4>
</div>
<div class="modal-body">
{{ form_start(leaveCommentForm) }}
<input type="hidden" value="{{ post.id }}" name="postId"> {{ post.id }}
{{ form_end(leaveCommentForm) }}
</div>
</div><!-- /.modal-content -->
</div><!-- /.modal-dialog -->
</div><!-- /.modal -->
</article>
</li>
{% endfor %}
</ul>
As you can see I want to display my form on each iteration of post (with or without modal I don't really care I was just trying some things).
My problems here are:
*If I use a modal, I can't get my post.id inside my modal and so I can't send it to my controller.
Actually I get the value of first post.id for every posts.
*If I don't use a modal I can't even see my form on my page.
If you have a solution that would be great!
Thanks in advance guys!