{% macro render_field_with_errors(field) %}
  <div class="form-group">
    {{ field.label(class_='control-label col-sm-3') }}
    <div class="col-sm-6">
      {{ field(class_='form-control', **kwargs)|safe }}
      {% if field.errors %}
        <ul class="list-unstyled text-warning">
          {% for error in field.errors %}
            <li>{{ error }}</li>
          {% endfor %}
        </ul>
      {% endif %}
    </div>
  </div>
{% endmacro %}

{% macro render_field(field) %}
  {% if field.type == 'HiddenField' %}
    {{ field(**kwargs)|safe }}
  {% elif field.type == 'SubmitField' %}
    <div class="col-sm-6 col-sm-offset-3">{{ field(class_='btn btn-default btn-lg', **kwargs)|safe }}</div>
  {% else %}
    <div class="form-group">{{ field(class_='form-control', **kwargs)|safe }}</div>
  {% endif %}
{% endmacro %}
{% macro render_field_with_errors(field) %}
  <div class="form-group">
    {{ field.label(class_='control-label col-sm-3') }}
    <div class="col-sm-6">
      {{ field(class_='form-control', **kwargs)|safe }}
      {% if field.errors %}
        <ul class="list-unstyled text-warning">
          {% for error in field.errors %}
            <li>{{ error }}</li>
          {% endfor %}
        </ul>
      {% endif %}
    </div>
  </div>
{% endmacro %}

{% macro render_field(field) %}
  {% if field.type == 'HiddenField' %}
    {{ field(**kwargs)|safe }}
  {% elif field.type == 'SubmitField' %}
    <div class="row">
      <div class="col-sm-6 col-sm-offset-3">{{ field(class_='btn btn-default btn-lg', **kwargs)|safe }}</div>
    </div>
  {% else %}
    <div class="form-group">{{ field(class_='form-control', **kwargs)|safe }}</div>
  {% endif %}
{% endmacro %}

Add row around form submit buttons
Add row around form submit buttons
