{% macro render_field(field) %}
<div class="form-group {% if field.errors %}has-error{% endif %}">{{ field.label(class_="control-label col-sm-3") }}
  <div class="col-sm-5">{{ field(class_="form-control") }}</div>
  {% for error in field.errors %}
    <span class="glyphicon glyphicon-exclamation-sign" aria-hidden="true"></span>
    <span class="sr-only">Error:</span>
    {{ error }}
  {% endfor %}
</div>
{%- endmacro %}

{% macro render_button(button) %}
<div class="form-group"><div class="col-sm-offset-3 col-sm-5">{{ button(class_="btn btn-primary") }}</div></div>
{%- endmacro %}