{% macro form_row_append(field, append) %}
    <div class="form-group">
        {{ form_label(field) }}
        {{ _self.form_widget_append(field, append) }}
    </div>
{% endmacro form_row_append %}

{% macro form_widget_append(field, append, params={}) %}
    <div class="form-widget">
        <div class="input-group">
            {{ form_widget(field, params) }}
            <div class="input-group-append">
                <span class="input-group-text">{{ append }}</span>
            </div>
        </div>
        {{ form_help(field) }}
    </div>
{% endmacro form_widget_append %}