diff options
Diffstat (limited to 'django/newforms/widgets.py')
| -rw-r--r-- | django/newforms/widgets.py | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/django/newforms/widgets.py b/django/newforms/widgets.py new file mode 100644 index 0000000000..18bba31897 --- /dev/null +++ b/django/newforms/widgets.py @@ -0,0 +1,353 @@ +""" +HTML Widget classes +""" + +__all__ = ( + 'Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'MultipleHiddenInput', + 'FileInput', 'Textarea', 'CheckboxInput', + 'Select', 'NullBooleanSelect', 'SelectMultiple', 'RadioSelect', 'CheckboxSelectMultiple', + 'MultiWidget', 'SplitDateTimeWidget', +) + +from util import flatatt, StrAndUnicode, smart_unicode +from django.utils.datastructures import MultiValueDict +from django.utils.html import escape +from django.utils.translation import gettext +from itertools import chain + +try: + set # Only available in Python 2.4+ +except NameError: + from sets import Set as set # Python 2.3 fallback + +class Widget(object): + is_hidden = False # Determines whether this corresponds to an <input type="hidden">. + + def __init__(self, attrs=None): + self.attrs = attrs or {} + + def render(self, name, value, attrs=None): + """ + Returns this Widget rendered as HTML, as a Unicode string. + + The 'value' given is not guaranteed to be valid input, so subclass + implementations should program defensively. + """ + raise NotImplementedError + + def build_attrs(self, extra_attrs=None, **kwargs): + "Helper function for building an attribute dictionary." + attrs = dict(self.attrs, **kwargs) + if extra_attrs: + attrs.update(extra_attrs) + return attrs + + def value_from_datadict(self, data, name): + """ + Given a dictionary of data and this widget's name, returns the value + of this widget. Returns None if it's not provided. + """ + return data.get(name, None) + + def id_for_label(self, id_): + """ + Returns the HTML ID attribute of this Widget for use by a <label>, + given the ID of the field. Returns None if no ID is available. + + This hook is necessary because some widgets have multiple HTML + elements and, thus, multiple IDs. In that case, this method should + return an ID value that corresponds to the first ID in the widget's + tags. + """ + return id_ + id_for_label = classmethod(id_for_label) + +class Input(Widget): + """ + Base class for all <input> widgets (except type='checkbox' and + type='radio', which are special). + """ + input_type = None # Subclasses must define this. + + def render(self, name, value, attrs=None): + if value is None: value = '' + final_attrs = self.build_attrs(attrs, type=self.input_type, name=name) + if value != '': final_attrs['value'] = smart_unicode(value) # Only add the 'value' attribute if a value is non-empty. + return u'<input%s />' % flatatt(final_attrs) + +class TextInput(Input): + input_type = 'text' + +class PasswordInput(Input): + input_type = 'password' + + def __init__(self, attrs=None, render_value=True): + self.attrs = attrs or {} + self.render_value = render_value + + def render(self, name, value, attrs=None): + if not self.render_value: value=None + return super(PasswordInput, self).render(name, value, attrs) + +class HiddenInput(Input): + input_type = 'hidden' + is_hidden = True + +class MultipleHiddenInput(HiddenInput): + """ + A widget that handles <input type="hidden"> for fields that have a list + of values. + """ + def __init__(self, attrs=None, choices=()): + # choices can be any iterable + self.attrs = attrs or {} + self.choices = choices + + def render(self, name, value, attrs=None, choices=()): + if value is None: value = [] + final_attrs = self.build_attrs(attrs, type=self.input_type, name=name) + return u'\n'.join([(u'<input%s />' % flatatt(dict(value=smart_unicode(v), **final_attrs))) for v in value]) + + def value_from_datadict(self, data, name): + if isinstance(data, MultiValueDict): + return data.getlist(name) + return data.get(name, None) + +class FileInput(Input): + input_type = 'file' + +class Textarea(Widget): + def render(self, name, value, attrs=None): + if value is None: value = '' + value = smart_unicode(value) + final_attrs = self.build_attrs(attrs, name=name) + return u'<textarea%s>%s</textarea>' % (flatatt(final_attrs), escape(value)) + +class CheckboxInput(Widget): + def __init__(self, attrs=None, check_test=bool): + # check_test is a callable that takes a value and returns True + # if the checkbox should be checked for that value. + self.attrs = attrs or {} + self.check_test = check_test + + def render(self, name, value, attrs=None): + final_attrs = self.build_attrs(attrs, type='checkbox', name=name) + try: + result = self.check_test(value) + except: # Silently catch exceptions + result = False + if result: + final_attrs['checked'] = 'checked' + if value not in ('', True, False, None): + final_attrs['value'] = smart_unicode(value) # Only add the 'value' attribute if a value is non-empty. + return u'<input%s />' % flatatt(final_attrs) + +class Select(Widget): + def __init__(self, attrs=None, choices=()): + self.attrs = attrs or {} + # choices can be any iterable, but we may need to render this widget + # multiple times. Thus, collapse it into a list so it can be consumed + # more than once. + self.choices = list(choices) + + def render(self, name, value, attrs=None, choices=()): + if value is None: value = '' + final_attrs = self.build_attrs(attrs, name=name) + output = [u'<select%s>' % flatatt(final_attrs)] + str_value = smart_unicode(value) # Normalize to string. + for option_value, option_label in chain(self.choices, choices): + option_value = smart_unicode(option_value) + selected_html = (option_value == str_value) and u' selected="selected"' or '' + output.append(u'<option value="%s"%s>%s</option>' % (escape(option_value), selected_html, escape(smart_unicode(option_label)))) + output.append(u'</select>') + return u'\n'.join(output) + +class NullBooleanSelect(Select): + """ + A Select Widget intended to be used with NullBooleanField. + """ + def __init__(self, attrs=None): + choices = ((u'1', gettext('Unknown')), (u'2', gettext('Yes')), (u'3', gettext('No'))) + super(NullBooleanSelect, self).__init__(attrs, choices) + + def render(self, name, value, attrs=None, choices=()): + try: + value = {True: u'2', False: u'3', u'2': u'2', u'3': u'3'}[value] + except KeyError: + value = u'1' + return super(NullBooleanSelect, self).render(name, value, attrs, choices) + + def value_from_datadict(self, data, name): + value = data.get(name, None) + return {u'2': True, u'3': False, True: True, False: False}.get(value, None) + +class SelectMultiple(Widget): + def __init__(self, attrs=None, choices=()): + # choices can be any iterable + self.attrs = attrs or {} + self.choices = choices + + def render(self, name, value, attrs=None, choices=()): + if value is None: value = [] + final_attrs = self.build_attrs(attrs, name=name) + output = [u'<select multiple="multiple"%s>' % flatatt(final_attrs)] + str_values = set([smart_unicode(v) for v in value]) # Normalize to strings. + for option_value, option_label in chain(self.choices, choices): + option_value = smart_unicode(option_value) + selected_html = (option_value in str_values) and ' selected="selected"' or '' + output.append(u'<option value="%s"%s>%s</option>' % (escape(option_value), selected_html, escape(smart_unicode(option_label)))) + output.append(u'</select>') + return u'\n'.join(output) + + def value_from_datadict(self, data, name): + if isinstance(data, MultiValueDict): + return data.getlist(name) + return data.get(name, None) + +class RadioInput(StrAndUnicode): + "An object used by RadioFieldRenderer that represents a single <input type='radio'>." + def __init__(self, name, value, attrs, choice, index): + self.name, self.value = name, value + self.attrs = attrs + self.choice_value = smart_unicode(choice[0]) + self.choice_label = smart_unicode(choice[1]) + self.index = index + + def __unicode__(self): + return u'<label>%s %s</label>' % (self.tag(), self.choice_label) + + def is_checked(self): + return self.value == self.choice_value + + def tag(self): + if self.attrs.has_key('id'): + self.attrs['id'] = '%s_%s' % (self.attrs['id'], self.index) + final_attrs = dict(self.attrs, type='radio', name=self.name, value=self.choice_value) + if self.is_checked(): + final_attrs['checked'] = 'checked' + return u'<input%s />' % flatatt(final_attrs) + +class RadioFieldRenderer(StrAndUnicode): + "An object used by RadioSelect to enable customization of radio widgets." + def __init__(self, name, value, attrs, choices): + self.name, self.value, self.attrs = name, value, attrs + self.choices = choices + + def __iter__(self): + for i, choice in enumerate(self.choices): + yield RadioInput(self.name, self.value, self.attrs.copy(), choice, i) + + def __getitem__(self, idx): + choice = self.choices[idx] # Let the IndexError propogate + return RadioInput(self.name, self.value, self.attrs.copy(), choice, idx) + + def __unicode__(self): + "Outputs a <ul> for this set of radio fields." + return u'<ul>\n%s\n</ul>' % u'\n'.join([u'<li>%s</li>' % w for w in self]) + +class RadioSelect(Select): + def render(self, name, value, attrs=None, choices=()): + "Returns a RadioFieldRenderer instance rather than a Unicode string." + if value is None: value = '' + str_value = smart_unicode(value) # Normalize to string. + attrs = attrs or {} + return RadioFieldRenderer(name, str_value, attrs, list(chain(self.choices, choices))) + + def id_for_label(self, id_): + # RadioSelect is represented by multiple <input type="radio"> fields, + # each of which has a distinct ID. The IDs are made distinct by a "_X" + # suffix, where X is the zero-based index of the radio field. Thus, + # the label for a RadioSelect should reference the first one ('_0'). + if id_: + id_ += '_0' + return id_ + id_for_label = classmethod(id_for_label) + +class CheckboxSelectMultiple(SelectMultiple): + def render(self, name, value, attrs=None, choices=()): + if value is None: value = [] + has_id = attrs and attrs.has_key('id') + final_attrs = self.build_attrs(attrs, name=name) + output = [u'<ul>'] + str_values = set([smart_unicode(v) for v in value]) # Normalize to strings. + for i, (option_value, option_label) in enumerate(chain(self.choices, choices)): + # If an ID attribute was given, add a numeric index as a suffix, + # so that the checkboxes don't all have the same ID attribute. + if has_id: + final_attrs = dict(final_attrs, id='%s_%s' % (attrs['id'], i)) + cb = CheckboxInput(final_attrs, check_test=lambda value: value in str_values) + option_value = smart_unicode(option_value) + rendered_cb = cb.render(name, option_value) + output.append(u'<li><label>%s %s</label></li>' % (rendered_cb, escape(smart_unicode(option_label)))) + output.append(u'</ul>') + return u'\n'.join(output) + + def id_for_label(self, id_): + # See the comment for RadioSelect.id_for_label() + if id_: + id_ += '_0' + return id_ + id_for_label = classmethod(id_for_label) + +class MultiWidget(Widget): + """ + A widget that is composed of multiple widgets. + + Its render() method takes a "decompressed" list of values, not a single + value. Each value in this list is rendered in the corresponding widget -- + the first value is rendered in the first widget, the second value is + rendered in the second widget, etc. + + Subclasses should implement decompress(), which specifies how a single + value should be converted to a list of values. Subclasses should not + have to implement clean(). + + Subclasses may implement format_output(), which takes the list of rendered + widgets and returns HTML that formats them any way you'd like. + + You'll probably want to use this with MultiValueField. + """ + def __init__(self, widgets, attrs=None): + self.widgets = [isinstance(w, type) and w() or w for w in widgets] + super(MultiWidget, self).__init__(attrs) + + def render(self, name, value, attrs=None): + # value is a list of values, each corresponding to a widget + # in self.widgets. + if not isinstance(value, list): + value = self.decompress(value) + output = [] + for i, widget in enumerate(self.widgets): + try: + widget_value = value[i] + except KeyError: + widget_value = None + output.append(widget.render(name + '_%s' % i, widget_value, attrs)) + return self.format_output(output) + + def value_from_datadict(self, data, name): + return [data.get(name + '_%s' % i) for i in range(len(self.widgets))] + + def format_output(self, rendered_widgets): + return u''.join(rendered_widgets) + + def decompress(self, value): + """ + Returns a list of decompressed values for the given compressed value. + The given value can be assumed to be valid, but not necessarily + non-empty. + """ + raise NotImplementedError('Subclasses must implement this method.') + +class SplitDateTimeWidget(MultiWidget): + """ + A Widget that splits datetime input into two <input type="text"> boxes. + """ + def __init__(self, attrs=None): + widgets = (TextInput(attrs=attrs), TextInput(attrs=attrs)) + super(SplitDateTimeWidget, self).__init__(widgets, attrs) + + def decompress(self, value): + if value: + return [value.date(), value.time()] + return [None, None] |