A macro for rending WTForm fields in Jinja2 templates with Bootstrap 3 styling.

wtforms-field-macro-bootstrap3.html

{% macro render_field(field) -%}

{% set with_label = kwargs.pop('with_label', False) %}
{% set placeholder = kwargs.pop('placeholder', field.label.text) %}
{% set class_ = kwargs.pop('class_', '') %}

{% if field.flags.required %}
{% set class_ = class_ + ' required' %}
{% endif %}

<div class="form-group {% if field.errors %}error{% endif %}">

    {% if with_label %}
    <label for="{{ field.id }}"
           class="control-label{% if field.flags.required %} required{% endif %}">
        {{ field.label.text }}
    </label>
    {% endif %}

    {% if field.type == 'BooleanField' %}
    <div class="checkbox">
        <label>
            {{ field(class_=class_, **kwargs) }}
            {{ field.label.text|safe }}
        </label>
    </div>
    {% else %}

    {% if field.type in ('TextField', 'TextAreaField', 'PasswordField',
                         'IntegerField') %}

    {% set class_ = class_ + ' input-xlarge form-control' %}

    {% elif field.type == 'FileField' %}

    {% set class_ = class_ + ' input-file form-control' %}

    {% endif %}

    {% if field.type == 'SelectField' %}

    {{ field(class_=class_, **kwargs) }}

    {% else %}

    {{ field(class_=class_, placeholder=placeholder, **kwargs) }}

    {% endif %}

    {% endif %}

    {% if field.errors %}
    <span class="error help-inline">{{ field.errors|join(', ') }}</span>
    {% endif %}

    {% if field.description %}
    <p class="help-block">{{ field.description|safe }}</p>
    {% endif %}

</div>
{%- endmacro %}

Can u please explain mo about that
N wat is the logic behind it

Use of kwargs.pop removes the items from the field object even after refreshing the page. I had to use kwargs.get