Firewall on Demand

import re

from django.template import Library, Node, Variable, TemplateSyntaxError

register = Library()

def silence_without_field(fn):

    def wrapped(field, attr):

        if not field:

            return ""

        return fn(field, attr)

    return wrapped

def _process_field_attributes(field, attr, process):

    # split attribute name and value from 'attr:value' string

    params = attr.split(':', 1)

    attribute = params[0]

    value = params[1] if len(params) == 2 else ''

    # decorate field.as_widget method with updated attributes

    old_as_widget = field.as_widget

    def as_widget(self, widget=None, attrs=None, only_initial=False):

        attrs = attrs or {}

        process(widget or self.field.widget, attrs, attribute, value)

        return old_as_widget(widget, attrs, only_initial)

    bound_method = type(old_as_widget)

    try:

        field.as_widget = bound_method(as_widget, field, field.__class__)

    except TypeError:  # python 3

        field.as_widget = bound_method(as_widget, field)

    return field

@register.filter("attr")

@silence_without_field

def set_attr(field, attr):

    def process(widget, attrs, attribute, value):

        attrs[attribute] = value

    return _process_field_attributes(field, attr, process)

@register.filter("add_error_attr")

@silence_without_field

def add_error_attr(field, attr):

    if hasattr(field, 'errors') and field.errors:

        return set_attr(field, attr)

    return field

@register.filter("append_attr")

@silence_without_field

def append_attr(field, attr):

    def process(widget, attrs, attribute, value):

        if attrs.get(attribute):

            attrs[attribute] += ' ' + value

        elif widget.attrs.get(attribute):

            attrs[attribute] = widget.attrs[attribute] + ' ' + value

        else:

            attrs[attribute] = value

    return _process_field_attributes(field, attr, process)

@register.filter("add_class")

@silence_without_field

def add_class(field, css_class):

    return append_attr(field, 'class:' + css_class)

@register.filter("add_error_class")

@silence_without_field

def add_error_class(field, css_class):

    if hasattr(field, 'errors') and field.errors:

        return add_class(field, css_class)

    return field

@register.filter("set_data")

@silence_without_field

def set_data(field, data):

    return set_attr(field, 'data-' + data)

@register.filter(name='field_type')

def field_type(field):

    """

    Template filter that returns field class name (in lower case).

    E.g. if field is CharField then {{ field|field_type }} will

    return 'charfield'.

    """

    if hasattr(field, 'field') and field.field:

        return field.field.__class__.__name__.lower()

    return ''

@register.filter(name='widget_type')

def widget_type(field):

    """

    Template filter that returns field widget class name (in lower case).

    E.g. if field's widget is TextInput then {{ field|widget_type }} will

    return 'textinput'.

    """

    if hasattr(field, 'field') and hasattr(field.field, 'widget') and field.field.widget:

        return field.field.widget.__class__.__name__.lower()

    return ''

# ======================== render_field tag ==============================

ATTRIBUTE_RE = re.compile(r"""

    (?P<attr>

        [\w_-]+

    )

    (?P<sign>

        \+?=

    )

    (?P<value>

    ['"]? # start quote

        [^"']*

    ['"]? # end quote

    )

""", re.VERBOSE | re.UNICODE)

@register.tag

def render_field(parser, token):

    """

    Render a form field using given attribute-value pairs

    Takes form field as first argument and list of attribute-value pairs for

    all other arguments.  Attribute-value pairs should be in the form of

    attribute=value or attribute="a value" for assignment and attribute+=value

    or attribute+="value" for appending.

    """

    error_msg = '%r tag requires a form field followed by a list of attributes and values in the form attr="value"' % token.split_contents()[0]

    try:

        bits = token.split_contents()

        tag_name = bits[0]

        form_field = bits[1]

        attr_list = bits[2:]

    except ValueError:

        raise TemplateSyntaxError(error_msg)

    form_field = parser.compile_filter(form_field)

    set_attrs = []

    append_attrs = []

    for pair in attr_list:

        match = ATTRIBUTE_RE.match(pair)

        if not match:

            raise TemplateSyntaxError(error_msg + ": %s" % pair)

        dct = match.groupdict()

        attr, sign, value = dct['attr'], dct['sign'], parser.compile_filter(dct['value'])

        if sign == "=":

            set_attrs.append((attr, value))

        else:

            append_attrs.append((attr, value))

    return FieldAttributeNode(form_field, set_attrs, append_attrs)

class FieldAttributeNode(Node):

    def __init__(self, field, set_attrs, append_attrs):

        self.field = field

        self.set_attrs = set_attrs

        self.append_attrs = append_attrs

    def render(self, context):

        bounded_field = self.field.resolve(context)

        field = getattr(bounded_field, 'field', None)

        if (getattr(bounded_field, 'errors', None) and

            'WIDGET_ERROR_CLASS' in context):

            bounded_field = append_attr(bounded_field, 'class:%s' %

                                        context['WIDGET_ERROR_CLASS'])

        if field and field.required and 'WIDGET_REQUIRED_CLASS' in context:

            bounded_field = append_attr(bounded_field, 'class:%s' %

                                        context['WIDGET_REQUIRED_CLASS'])

        for k, v in self.set_attrs:

            bounded_field = set_attr(bounded_field, '%s:%s' % (k,v.resolve(context)))

        for k, v in self.append_attrs:

            bounded_field = append_attr(bounded_field, '%s:%s' % (k,v.resolve(context)))

        return bounded_field

import string

try:

    from django.utils.unittest import expectedFailure

except ImportError:

    def expectedFailure(func):

        return lambda *args, **kwargs: None

from django.test import TestCase

from django.forms import Form, CharField, TextInput

from django import forms

from django.template import Template, Context

from django.forms.extras.widgets import SelectDateWidget

# ==============================

#       Testing helpers

# ==============================

class MyForm(Form):

    """

    Test form. If you want to test rendering of a field,

    add it to this form and use one of 'render_...' functions

    from this module.

    """

    simple = CharField()

    with_attrs = CharField(widget=TextInput(attrs={

                    'foo': 'baz',

                    'egg': 'spam'

                 }))

    with_cls = CharField(widget=TextInput(attrs={'class':'class0'}))

    date = forms.DateField(widget=SelectDateWidget(attrs={'egg': 'spam'}))

def render_form(text, form=None, **context_args):

    """

    Renders template ``text`` with widget_tweaks library loaded

    and MyForm instance available in context as ``form``.

    """

    tpl = Template("{% load widget_tweaks %}" + text)

    context_args.update({'form': MyForm() if form is None else form})

    context = Context(context_args)

    return tpl.render(context)

def render_field(field, template_filter, params, *args, **kwargs):

    """

    Renders ``field`` of MyForm with filter ``template_filter`` applied.

    ``params`` are filter arguments.

    If you want to apply several filters (in a chain),

    pass extra ``template_filter`` and ``params`` as positional arguments.

    In order to use custom form, pass form instance as ``form``

    keyword argument.

    """

    filters = [(template_filter, params)]

    filters.extend(zip(args[::2], args[1::2]))

    filter_strings = ['|%s:"%s"' % (f[0], f[1],) for f in filters]

    render_field_str = '{{ form.%s%s }}' % (field, ''.join(filter_strings))

    return render_form(render_field_str, **kwargs)

def render_field_from_tag(field, *attributes):

    """

    Renders MyForm's field ``field`` with attributes passed

    as positional arguments.

    """

    attr_strings = [' %s' % f for f in attributes]

    tpl = string.Template('{% render_field form.$field$attrs %}')

    render_field_str = tpl.substitute(field=field, attrs=''.join(attr_strings))

    return render_form(render_field_str)

def assertIn(value, obj):

    assert value in obj, "%s not in %s" % (value, obj,)

def assertNotIn(value, obj):

    assert value not in obj, "%s in %s" % (value, obj,)

# ===============================

#           Test cases

# ===============================

class SimpleAttrTest(TestCase):

    def test_attr(self):

        res = render_field('simple', 'attr', 'foo:bar')

        assertIn('type="text"', res)

        assertIn('name="simple"', res)

        assertIn('id="id_simple"', res)

        assertIn('foo="bar"', res)

    def test_attr_chaining(self):

        res = render_field('simple', 'attr', 'foo:bar', 'attr', 'bar:baz')

        assertIn('type="text"', res)

        assertIn('name="simple"', res)

        assertIn('id="id_simple"', res)

        assertIn('foo="bar"', res)

        assertIn('bar="baz"', res)

    def test_add_class(self):

        res = render_field('simple', 'add_class', 'foo')

        assertIn('class="foo"', res)

    def test_add_multiple_classes(self):

        res = render_field('simple', 'add_class', 'foo bar')

        assertIn('class="foo bar"', res)

    def test_add_class_chaining(self):

        res = render_field('simple', 'add_class', 'foo', 'add_class', 'bar')

        assertIn('class="bar foo"', res)

    def test_set_data(self):

        res = render_field('simple', 'set_data', 'key:value')

        assertIn('data-key="value"', res)

class ErrorsTest(TestCase):

    def _err_form(self):

        form = MyForm({'foo': 'bar'})  # some random data

        form.is_valid()  # trigger form validation

        return form

    def test_error_class_no_error(self):

        res = render_field('simple', 'add_error_class', 'err')

        assertNotIn('class="err"', res)

    def test_error_class_error(self):

        form = self._err_form()

        res = render_field('simple', 'add_error_class', 'err', form=form)

        assertIn('class="err"', res)

    def test_error_attr_no_error(self):

        res = render_field('simple', 'add_error_attr', 'aria-invalid:true')

        assertNotIn('aria-invalid="true"', res)

    def test_error_attr_error(self):

        form = self._err_form()

        res = render_field('simple', 'add_error_attr', 'aria-invalid:true', form=form)

        assertIn('aria-invalid="true"', res)

class SilenceTest(TestCase):

    def test_silence_without_field(self):

        res = render_field("nothing", 'attr', 'foo:bar')

        self.assertEqual(res, "")

        res = render_field("nothing", 'add_class', 'some')

        self.assertEqual(res, "")

class CustomizedWidgetTest(TestCase):

    def test_attr(self):

        res = render_field('with_attrs', 'attr', 'foo:bar')

        assertIn('foo="bar"', res)

        assertNotIn('foo="baz"', res)

        assertIn('egg="spam"', res)

    # see https://code.djangoproject.com/ticket/16754

    @expectedFailure

    def test_selectdatewidget(self):

        res = render_field('date', 'attr', 'foo:bar')

        assertIn('egg="spam"', res)

        assertIn('foo="bar"', res)

    def test_attr_chaining(self):

        res = render_field('with_attrs', 'attr', 'foo:bar', 'attr', 'bar:baz')

        assertIn('foo="bar"', res)

        assertNotIn('foo="baz"', res)

        assertIn('egg="spam"', res)

        assertIn('bar="baz"', res)

    def test_attr_class(self):

        res = render_field('with_cls', 'attr', 'foo:bar')

        assertIn('foo="bar"', res)

        assertIn('class="class0"', res)

    def test_default_attr(self):

        res = render_field('with_cls', 'attr', 'type:search')

        assertIn('class="class0"', res)

        assertIn('type="search"', res)

    def test_add_class(self):

        res = render_field('with_cls', 'add_class', 'class1')

        assertIn('class0', res)

        assertIn('class1', res)

    def test_add_class_chaining(self):

        res = render_field('with_cls', 'add_class', 'class1', 'add_class', 'class2')

        assertIn('class0', res)

        assertIn('class1', res)

        assertIn('class2', res)

class FieldReuseTest(TestCase):

    def test_field_double_rendering_simple(self):

        res = render_form('{{ form.simple }}{{ form.simple|attr:"foo:bar" }}{{ form.simple }}')

        self.assertEqual(res.count("bar"), 1)

    def test_field_double_rendering_simple_css(self):

        res = render_form('{{ form.simple }}{{ form.simple|add_class:"bar" }}{{ form.simple|add_class:"baz" }}')

        self.assertEqual(res.count("baz"), 1)

        self.assertEqual(res.count("bar"), 1)

    def test_field_double_rendering_attrs(self):

        res = render_form('{{ form.with_cls }}{{ form.with_cls|add_class:"bar" }}{{ form.with_cls }}')

        self.assertEqual(res.count("class0"), 3)

        self.assertEqual(res.count("bar"), 1)

class SimpleRenderFieldTagTest(TestCase):

    def test_attr(self):

        res = render_field_from_tag('simple', 'foo="bar"')

        assertIn('type="text"', res)

        assertIn('name="simple"', res)

        assertIn('id="id_simple"', res)

        assertIn('foo="bar"', res)

    def test_multiple_attrs(self):

        res = render_field_from_tag('simple', 'foo="bar"', 'bar="baz"')

        assertIn('type="text"', res)

        assertIn('name="simple"', res)

        assertIn('id="id_simple"', res)

        assertIn('foo="bar"', res)

        assertIn('bar="baz"', res)

class RenderFieldTagSilenceTest(TestCase):

    def test_silence_without_field(self):

        res = render_field_from_tag("nothing", 'foo="bar"')

        self.assertEqual(res, "")

        res = render_field_from_tag("nothing", 'class+="some"')

        self.assertEqual(res, "")

class RenderFieldTagCustomizedWidgetTest(TestCase):

    def test_attr(self):

        res = render_field_from_tag('with_attrs', 'foo="bar"')

        assertIn('foo="bar"', res)

        assertNotIn('foo="baz"', res)

        assertIn('egg="spam"', res)

    # see https://code.djangoproject.com/ticket/16754

    @expectedFailure

    def test_selectdatewidget(self):

        res = render_field_from_tag('date', 'foo="bar"')

        assertIn('egg="spam"', res)

        assertIn('foo="bar"', res)

    def test_multiple_attrs(self):

        res = render_field_from_tag('with_attrs', 'foo="bar"', 'bar="baz"')

        assertIn('foo="bar"', res)

        assertNotIn('foo="baz"', res)

        assertIn('egg="spam"', res)

        assertIn('bar="baz"', res)

    def test_attr_class(self):

        res = render_field_from_tag('with_cls', 'foo="bar"')

        assertIn('foo="bar"', res)

        assertIn('class="class0"', res)

    def test_default_attr(self):

        res = render_field_from_tag('with_cls', 'type="search"')

        assertIn('class="class0"', res)

        assertIn('type="search"', res)

    def test_append_attr(self):

        res = render_field_from_tag('with_cls', 'class+="class1"')

        assertIn('class0', res)

        assertIn('class1', res)

    def test_duplicate_append_attr(self):

        res = render_field_from_tag('with_cls', 'class+="class1"', 'class+="class2"')

        assertIn('class0', res)

        assertIn('class1', res)

        assertIn('class2', res)

    def test_hyphenated_attributes(self):

        res = render_field_from_tag('with_cls', 'data-foo="bar"')

        assertIn('data-foo="bar"', res)

        assertIn('class="class0"', res)

class RenderFieldWidgetClassesTest(TestCase):

    def test_use_widget_required_class(self):

        res = render_form('{% render_field form.simple %}',

                          WIDGET_REQUIRED_CLASS='required_class')

        assertIn('class="required_class"', res)

    def test_use_widget_error_class(self):

        res = render_form('{% render_field form.simple %}', form=MyForm({}),

                          WIDGET_ERROR_CLASS='error_class')

        assertIn('class="error_class"', res)

    def test_use_widget_error_class_with_other_classes(self):

        res = render_form('{% render_field form.simple class="blue" %}',

                          form=MyForm({}), WIDGET_ERROR_CLASS='error_class')

        assertIn('class="blue error_class"', res)

    def test_use_widget_required_class_with_other_classes(self):

        res = render_form('{% render_field form.simple class="blue" %}',

                          form=MyForm({}), WIDGET_REQUIRED_CLASS='required_class')

        assertIn('class="blue required_class"', res)

class RenderFieldTagFieldReuseTest(TestCase):

    def test_field_double_rendering_simple(self):

        res = render_form('{{ form.simple }}{% render_field form.simple foo="bar" %}{% render_field form.simple %}')

        self.assertEqual(res.count("bar"), 1)

    def test_field_double_rendering_simple_css(self):

        res = render_form('{% render_field form.simple %}{% render_field form.simple class+="bar" %}{% render_field form.simple class+="baz" %}')

        self.assertEqual(res.count("baz"), 1)

        self.assertEqual(res.count("bar"), 1)

    def test_field_double_rendering_attrs(self):

        res = render_form('{% render_field form.with_cls %}{% render_field form.with_cls class+="bar" %}{% render_field form.with_cls %}')

        self.assertEqual(res.count("class0"), 3)

        self.assertEqual(res.count("bar"), 1)

class RenderFieldTagUseTemplateVariableTest(TestCase):

    def test_use_template_variable_in_parametrs(self):

        res = render_form('{% render_field form.with_attrs egg+="pahaz" placeholder=form.with_attrs.label %}')

        assertIn('egg="spam pahaz"', res)

        assertIn('placeholder="With attrs"', res)

class RenderFieldFilter_field_type_widget_type_Test(TestCase):

    def test_field_type_widget_type_rendering_simple(self):

        res = render_form('<div class="{{ form.simple|field_type }} {{ form.simple|widget_type }} {{ form.simple.html_name }}">{{ form.simple }}</div>')

        assertIn('class="charfield textinput simple"', res)