{% macro form_field(field, placeholder=False, class="") %}
    {% with css_class = "error" if field.errors else "",
            errors = field.errors | join(", ") %}
        {% if field.type == "BooleanField" %}
            <div class="checkbox control-group {{ css_class }} {{ class }}">
                {{ field }}
                {{ field.label(class="control-label") }}
                {% if field.errors %}
                    <span class="help-inline">{{ errors }}</span>
                {% endif %}
            </div>
        {% elif placeholder %}
            <div class="control-group {{ css_class }} {{ class }}">
                <div class="controls">
                    {{ field(placeholder=field.label.text) }}
                    {% if field.errors %}
                        <span class="help-inline">{{ errors }}</span>
                    {% endif %}
                </div>
            </div>
        {% else %}
            <div class="control-group {{ css_class }} {{ class }}">
                {{ field.label(class="control-label") }}
                <div class="controls">
                    {{ field }}
                    {% if field.errors %}
                        <span class="help-inline">{{ errors }}</span>
                    {% endif %}
                </div>
            </div>
        {% endif %}
    {% endwith %}
{% endmacro %}