Customising form labels in Symfony - symfony

Question

I have a symfony page where I display a form, and I would like to add an
* in the labels of all fields that are required.
So I have my form.php.twig, that looks like this:
{% extends "::layout.php.twig" %}
{% block body %}
<div class="row">
{% use 'form_div_layout.html.twig' with form_label as base_form_label %}
{% block form_label %}
{{ block('base_form_label') }}
{% if required %}
<span class="required" title="This field is required">*</span>
{% endif %}
{% endblock %}
</div>
{% endblock %}
I followed the exact documentation of the symfony cookbook on how to customise labels, which is http://symfony.com/doc/current/cookbook/form/form_customization.html#cookbook-form-theming-methods.
But I keep getting this error
Variable "label" does not exist in form_div_layout.html.twig at line 206
I don't have any label variable in the code of my form.php.twig so I don't see why I get this error. And when I remove the
{{ block('base_form_label') }}
I get
Variable "required" does not exist in ATPlatformBundle:Session:create.php.twig
Can anyone help me on this? I don't see where is my mistake? I am not looking to customise it with css, but to add the * .
I have checked the form_div_layout.html.twig at line 206 and this is what there is
{%- block form_label -%}
{% if label is not sameas(false) -%}
{% if not compound -%}
{% set label_attr = label_attr|merge({'for': id}) %}
{%- endif %}
{% if required -%}
{% set label_attr = label_attr|merge({'class': (label_attr.class|default('') ~ ' required')|trim}) %}
{%- endif %}
{% if label is empty -%}
{%- if label_format is not empty -%}
{% set label = label_format|replace({
'%name%': name,
'%id%': id,
}) %}
{%- else -%}
{% set label = name|humanize %}
{%- endif -%}
{%- endif -%}
<label{% for attrname, attrvalue in label_attr %} {{ attrname }}="{{ attrvalue }}"{% endfor %}>{{ translation_domain is sameas(false) ? label : label|trans({}, translation_domain) }}</label>
{%- endif -%}
{%- endblock form_label -%}
Thank you in advance.

Answer 1

Did you try defining the label from inside your form builder?! The below field is a required one because unless you mention required => false, your field will be rendered as required.
Something like:
->add('name', 'text', array('label' => '* name'))

Answer 2

With Twig, you should have to test the existence of a variable before using it:
Variable "required" does not exist
{% if required is defined and ... }
You need to test this because you field isn't always required.
if you want further information, you have this page of the documentation:
http://twig.sensiolabs.org/doc/tests/defined.html

Answer 3

Ok, so at the end, I didn't manage to change labels within my form.php.twig (which is the template I use to display my form), but I used another technique.
I created a new file named fields.php.twig, which I put in MyBundle/Resources/views/Form.
At the beginning of my fields.php.twig, I then added
{% extends 'form_div_layout.html.twig' %}
and below it, I added
{% block form_label %}
{{ parent() }}
{% if required %}
<span> * </span>
{% endif %}
{% endblock form_label %}
Then in my form.php.twig, I added
{% form_theme form 'MyBundle:Form:fields.php.twig' %}
{{ form_start(form) }}
Myform here with {{ form_label(form.property) }}
{{ form_errors(form.property) }}
{{ form_widget(form.property) }}
{{ form_end(form) }}
It works perfectly, but I had to create the fields.php.twig.