Add form input fields utility

widget_tweaks/__init__.py

+

widget_tweaks/models.py

+

widget_tweaks/templatetags/__init__.py

+

widget_tweaks/templatetags/widget_tweaks.py

+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

widget_tweaks/tests.py

+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)