Customize the rendering of a choice/entity field in Symfony2

1. Manually rendering. Better if is a individual form for field and not repeated somethere as it requires less time to work.

A) Get name of field you can with form.service.vars.full_name

B) List of choices - form.service.vars.choices. Its an array of ChoiceView, to get entity simply access public data property.

{% for choice in form.service.vars.choices %}    {% set service_entity = choice.data %}{% endfor %}

2. Via overriding templates. IF you like to brute-force pick up the name of the blocks which must be overriden.

A) You can only override widget, label and errors blocks as documentation said. You can specify block by widget name(documentation). Something like

{% block _form_service_widget %}    {% if expanded %}        {{ block('choice_widget_expanded') }}    {% else %}        {{ block('my_service_widget') }}    {% endif %}{% endblock %}{% block my_service_widget %}{% spaceless %}    <select {{ block('widget_attributes') }}{% if multiple %} multiple="multiple"{% endif %}>        {% if empty_value is not none %}            <option value="">{{ empty_value|trans({}, translation_domain) }}</option>        {% endif %}        {% set options = choices %}        {{ block('my_service_options') }}    </select>{% endspaceless %}{% endblock my_service_widget %}{% block my_service_options %}{% spaceless %}    {% for group_label, choice in options %}        {# here you can access choice #}        <option value="{{ choice.value }}"{% if choice is selectedchoice(value) %} selected="selected"{% endif %}>{{ choice.label|trans({}, translation_domain) }}</option>    {% endfor %}{% endspaceless %}{% endblock my_service_options %}

You can use the choice_attr option in the form builder:

$builder->add('myField', ChoiceType:class, [        ....        'choice_attr' => function($val, $key, $index) {            return ['data' => '...', 'class' => '', ... etc ];        },        ....]);

This will apply attributes to each option, checkbox, radio in your choice (depending on your expanded and multiple option choices)