File: templates/blog/_comment_form.html.twig

{#
    By default, forms enable client-side validation. This means that you can't
    test the server-side validation errors from the browser. To temporarily
    disable this validation, add the 'novalidate' attribute:

    {{ form_start(form, {method: ..., action: ..., attr: {novalidate: 'novalidate'}}) }}
#}

{{ form_start(form, {method: 'POST', action: path('comment_new', {'postSlug': post.slug})}) }}
    {#  instead of displaying form fields one by one, you can also display them
        all with their default options and styles just by calling to this function:

        {{ form_widget(form) }}
    #}

    <fieldset>
        <legend>
            <i class="fa fa-comment" aria-hidden="true"></i> {{ 'title.add_comment'|trans }}
        </legend>

        {# Render any global form error (e.g. when a constraint on a public getter method failed) #}
        {{ form_errors(form) }}

        <div class="form-group {% if not form.content.vars.valid %}has-error{% endif %}">
            {{ form_label(form.content, 'label.content', {label_attr: {class: 'hidden'}}) }}

            {# Render any errors for the "content" field (e.g. when a class property constraint failed) #}
            {{ form_errors(form.content) }}

            {{ form_widget(form.content, {attr: {rows: 10}}) }}
            {{ form_help(form.content) }}
        </div>

        <div class="form-group">
            <button class="btn btn-primary pull-right" type="submit">
                <i class="fa fa-paper-plane" aria-hidden="true"></i> {{ 'action.publish_comment'|trans }}
            </button>
        </div>
    </fieldset>
{{ form_end(form) }}