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|
"""$URL: svn+ssh://svn.mems-exchange.org/repos/trunk/quixote/form1/widget.py $
$Id: widget.py 25664 2004-11-22 20:35:07Z nascheme $
Provides the basic web widget classes: Widget itself, plus StringWidget,
TextWidget, CheckboxWidget, etc.
"""
import struct
from types import FloatType, IntType, ListType, StringType, TupleType
from quixote import get_request
from quixote.html import htmltext, htmlescape, htmltag
from quixote.http_request import Upload
class FormValueError (Exception):
"""Raised whenever a widget has problems parsing its value."""
def __init__(self, msg):
self.msg = msg
def __str__(self):
return str(self.msg)
class Widget:
"""Abstract base class for web widgets. The key elements
of a web widget are:
- name
- widget type (how the widget looks/works in the browser)
- value
The name and value are instance attributes (because they're specific to
a particular widget in a particular context); widget type is a
class attributes.
Instance attributes:
name : string
value : any
Feel free to access these directly; to set them, use the 'set_*()'
modifier methods.
"""
# Subclasses must define. 'widget_type' is just a string, e.g.
# "string", "text", "checkbox".
widget_type = None
def __init__(self, name, value=None):
assert self.__class__ is not Widget, "abstract class"
self.set_name(name)
self.set_value(value)
def __repr__(self):
return "<%s at %x: %s>" % (self.__class__.__name__,
id(self),
self.name)
def __str__(self):
return "%s: %s" % (self.widget_type, self.name)
def set_name(self, name):
self.name = name
def set_value(self, value):
self.value = value
def clear(self):
self.value = None
# -- Subclasses must implement these -------------------------------
def render(self, request):
"""render(request) -> HTML text"""
raise NotImplementedError
def parse(self, request):
"""parse(request) -> any"""
value = request.form.get(self.name)
if type(value) is StringType and value.strip():
self.value = value
else:
self.value = None
return self.value
# -- Convenience methods for subclasses ----------------------------
# This one's really only for composite widgets; lives here until
# we have a demonstrated need for a CompositeWidget class.
def get_subwidget_name(self, name):
return "%s$%s" % (self.name, name)
def create_subwidget(self, widget_type, widget_name, value=None, **args):
from quixote.form.form import get_widget_class
klass = get_widget_class(widget_type)
name = self.get_subwidget_name(widget_name)
return apply(klass, (name, value), args)
# class Widget
# -- Fundamental widget types ------------------------------------------
# These correspond to the standard types of input tag in HTML:
# text StringWidget
# password PasswordWidget
# radio RadiobuttonWidget
# checkbox CheckboxWidget
#
# and also to the other basic form elements:
# <textarea> TextWidget
# <select> SingleSelectWidget
# <select multiple>
# MultipleSelectWidget
class StringWidget (Widget):
"""Widget for entering a single string: corresponds to
'<input type="text">' in HTML.
Instance attributes:
value : string
size : int
maxlength : int
"""
widget_type = "string"
# This lets PasswordWidget be a trivial subclass
html_type = "text"
def __init__(self, name, value=None,
size=None, maxlength=None):
Widget.__init__(self, name, value)
self.size = size
self.maxlength = maxlength
def render(self, request, **attributes):
return htmltag("input", xml_end=1,
type=self.html_type,
name=self.name,
size=self.size,
maxlength=self.maxlength,
value=self.value,
**attributes)
class FileWidget (StringWidget):
"""Trivial subclass of StringWidget for uploading files.
Instance attributes: none
"""
widget_type = "file"
html_type = "file"
def parse(self, request):
"""parse(request) -> any"""
value = request.form.get(self.name)
if isinstance(value, Upload):
self.value = value
else:
self.value = None
return self.value
class PasswordWidget (StringWidget):
"""Trivial subclass of StringWidget for entering passwords (different
widget type because HTML does it that way).
Instance attributes: none
"""
widget_type = "password"
html_type = "password"
class TextWidget (Widget):
"""Widget for entering a long, multi-line string; corresponds to
the HTML "<textarea>" tag.
Instance attributes:
value : string
cols : int
rows : int
wrap : string
(see an HTML book for details on text widget wrap options)
css_class : string
"""
widget_type = "text"
def __init__(self, name, value=None, cols=None, rows=None, wrap=None,
css_class=None):
Widget.__init__(self, name, value)
self.cols = cols
self.rows = rows
self.wrap = wrap
self.css_class = css_class
def render(self, request):
return (htmltag("textarea", name=self.name,
cols=self.cols,
rows=self.rows,
wrap=self.wrap,
css_class=self.css_class) +
htmlescape(self.value or "") +
htmltext("</textarea>"))
def parse(self, request):
value = Widget.parse(self, request)
if value:
value = value.replace("\r\n", "\n")
self.value = value
return self.value
class CheckboxWidget (Widget):
"""Widget for a single checkbox: corresponds to "<input
type=checkbox>". Do not put multiple CheckboxWidgets with the same
name in the same form.
Instance attributes:
value : boolean
"""
widget_type = "checkbox"
def render(self, request):
return htmltag("input", xml_end=1,
type="checkbox",
name=self.name,
value="yes",
checked=self.value and "checked" or None)
def parse(self, request):
self.value = request.form.has_key(self.name)
return self.value
class SelectWidget (Widget):
"""Widget for single or multiple selection; corresponds to
<select name=...>
<option value="Foo">Foo</option>
...
</select>
Instance attributes:
options : [ (value:any, description:any, key:string) ]
value : any
The value is None or an element of dict(options.values()).
size : int
The number of options that should be presented without scrolling.
"""
# NB. 'widget_type' not set here because this is an abstract class: it's
# set by subclasses SingleSelectWidget and MultipleSelectWidget.
def __init__(self, name, value=None,
allowed_values=None,
descriptions=None,
options=None,
size=None,
sort=0,
verify_selection=1):
assert self.__class__ is not SelectWidget, "abstract class"
self.options = []
# if options passed, cannot pass allowed_values or descriptions
if allowed_values is not None:
assert options is None, (
'cannot pass both allowed_values and options')
assert allowed_values, (
'cannot pass empty allowed_values list')
self.set_allowed_values(allowed_values, descriptions, sort)
elif options is not None:
assert descriptions is None, (
'cannot pass both options and descriptions')
assert options, (
'cannot pass empty options list')
self.set_options(options, sort)
self.set_name(name)
self.set_value(value)
self.size = size
self.verify_selection = verify_selection
def get_allowed_values(self):
return [item[0] for item in self.options]
def get_descriptions(self):
return [item[1] for item in self.options]
def set_value(self, value):
self.value = None
for object, description, key in self.options:
if value == object:
self.value = value
break
def _generate_keys(self, values, descriptions):
"""Called if no keys were provided. Try to generate a set of keys
that will be consistent between rendering and parsing.
"""
# try to use ZODB object IDs
keys = []
for value in values:
if value is None:
oid = ""
else:
oid = getattr(value, "_p_oid", None)
if not oid:
break
hi, lo = struct.unpack(">LL", oid)
oid = "%x" % ((hi << 32) | lo)
keys.append(oid)
else:
# found OID for every value
return keys
# can't use OIDs, try using descriptions
used_keys = {}
keys = map(str, descriptions)
for key in keys:
if used_keys.has_key(key):
raise ValueError, "duplicated descriptions (provide keys)"
used_keys[key] = 1
return keys
def set_options(self, options, sort=0):
"""(options: [objects:any], sort=0)
or
(options: [(object:any, description:any)], sort=0)
or
(options: [(object:any, description:any, key:any)], sort=0)
"""
"""
Set the options list. The list of options can be a list of objects, in
which case the descriptions default to map(htmlescape, objects)
applying htmlescape() to each description and
key.
If keys are provided they must be distinct. If the sort keyword
argument is true, sort the options by case-insensitive lexicographic
order of descriptions, except that options with value None appear
before others.
"""
if options:
first = options[0]
values = []
descriptions = []
keys = []
if type(first) is TupleType:
if len(first) == 2:
for value, description in options:
values.append(value)
descriptions.append(description)
elif len(first) == 3:
for value, description, key in options:
values.append(value)
descriptions.append(description)
keys.append(str(key))
else:
raise ValueError, 'invalid options %r' % options
else:
values = descriptions = options
if not keys:
keys = self._generate_keys(values, descriptions)
options = zip(values, descriptions, keys)
if sort:
def make_sort_key(option):
value, description, key = option
if value is None:
return ('', option)
else:
return (str(description).lower(), option)
doptions = map(make_sort_key, options)
doptions.sort()
options = [item[1] for item in doptions]
self.options = options
def parse_single_selection(self, parsed_key):
for value, description, key in self.options:
if key == parsed_key:
return value
else:
if self.verify_selection:
raise FormValueError, "invalid value selected"
else:
return self.options[0][0]
def set_allowed_values(self, allowed_values, descriptions=None, sort=0):
"""(allowed_values:[any], descriptions:[any], sort:boolean=0)
Set the options for this widget. The allowed_values and descriptions
parameters must be sequences of the same length. The sort option
causes the options to be sorted using case-insensitive lexicographic
order of descriptions, except that options with value None appear
before others.
"""
if descriptions is None:
self.set_options(allowed_values, sort)
else:
assert len(descriptions) == len(allowed_values)
self.set_options(zip(allowed_values, descriptions), sort)
def is_selected(self, value):
return value == self.value
def render(self, request):
if self.widget_type == "multiple_select":
multiple = "multiple"
else:
multiple = None
if self.widget_type == "option_select":
onchange = "submit()"
else:
onchange = None
tags = [htmltag("select", name=self.name,
multiple=multiple, onchange=onchange,
size=self.size)]
for object, description, key in self.options:
if self.is_selected(object):
selected = "selected"
else:
selected = None
if description is None:
description = ""
r = htmltag("option", value=key, selected=selected)
tags.append(r + htmlescape(description) + htmltext('</option>'))
tags.append(htmltext("</select>"))
return htmltext("\n").join(tags)
class SingleSelectWidget (SelectWidget):
"""Widget for single selection.
"""
widget_type = "single_select"
def parse(self, request):
parsed_key = request.form.get(self.name)
self.value = None
if parsed_key:
if type(parsed_key) is ListType:
raise FormValueError, "cannot select multiple values"
self.value = self.parse_single_selection(parsed_key)
return self.value
class RadiobuttonsWidget (SingleSelectWidget):
"""Widget for a *set* of related radiobuttons -- all have the
same name, but different values (and only one of those values
is returned by the whole group).
Instance attributes:
delim : string = None
string to emit between each radiobutton in the group. If
None, a single newline is emitted.
"""
widget_type = "radiobuttons"
def __init__(self, name, value=None,
allowed_values=None,
descriptions=None,
options=None,
delim=None):
SingleSelectWidget.__init__(self, name, value, allowed_values,
descriptions, options)
if delim is None:
self.delim = "\n"
else:
self.delim = delim
def render(self, request):
tags = []
for object, description, key in self.options:
if self.is_selected(object):
checked = "checked"
else:
checked = None
r = htmltag("input", xml_end=True,
type="radio",
name=self.name,
value=key,
checked=checked)
tags.append(r + htmlescape(description))
return htmlescape(self.delim).join(tags)
class MultipleSelectWidget (SelectWidget):
"""Widget for multiple selection.
Instance attributes:
value : [any]
for multipe selects, the value is None or a list of
elements from dict(self.options).values()
"""
widget_type = "multiple_select"
def set_value(self, value):
allowed_values = self.get_allowed_values()
if value in allowed_values:
self.value = [ value ]
elif type(value) in (ListType, TupleType):
self.value = [ element
for element in value
if element in allowed_values ] or None
else:
self.value = None
def is_selected(self, value):
if self.value is None:
return value is None
else:
return value in self.value
def parse(self, request):
parsed_keys = request.form.get(self.name)
self.value = None
if parsed_keys:
if type(parsed_keys) is ListType:
self.value = [value
for value, description, key in self.options
if key in parsed_keys] or None
else:
self.value = [self.parse_single_selection(parsed_keys)]
return self.value
class SubmitButtonWidget (Widget):
"""
Instance attributes:
value : boolean
"""
widget_type = "submit_button"
def __init__(self, name=None, value=None):
Widget.__init__(self, name, value)
def render(self, request):
value = (self.value and htmlescape(self.value) or None)
return htmltag("input", xml_end=1, type="submit",
name=self.name, value=value)
def parse(self, request):
return request.form.get(self.name)
def is_submitted(self):
return self.parse(get_request())
class HiddenWidget (Widget):
"""
Instance attributes:
value : string
"""
widget_type = "hidden"
def render(self, request):
if self.value is None:
value = None
else:
value = htmlescape(self.value)
return htmltag("input", xml_end=1,
type="hidden",
name=self.name,
value=value)
def set_current_value(self, value):
self.value = value
request = get_request()
if request.form:
request.form[self.name] = value
def get_current_value(self):
request = get_request()
if request.form:
return self.parse(request)
else:
return self.value
# -- Derived widget types ----------------------------------------------
# (these don't correspond to fundamental widget types in HTML,
# so they're separated)
class NumberWidget (StringWidget):
"""
Instance attributes: none
"""
# Parameterize the number type (either float or int) through
# these class attributes:
type_object = None # eg. int, float
type_error = None # human-readable error message
type_converter = None # eg. int(), float()
def __init__(self, name,
value=None,
size=None, maxlength=None):
assert self.__class__ is not NumberWidget, "abstract class"
assert value is None or type(value) is self.type_object, (
"form value '%s' not a %s: got %r" % (name,
self.type_object,
value))
StringWidget.__init__(self, name, value, size, maxlength)
def parse(self, request):
value = StringWidget.parse(self, request)
if value:
try:
self.value = self.type_converter(value)
except ValueError:
raise FormValueError, self.type_error
return self.value
class FloatWidget (NumberWidget):
"""
Instance attributes:
value : float
"""
widget_type = "float"
type_object = FloatType
type_converter = float
type_error = "must be a number"
class IntWidget (NumberWidget):
"""
Instance attributes:
value : int
"""
widget_type = "int"
type_object = IntType
type_converter = int
type_error = "must be an integer"
class OptionSelectWidget (SingleSelectWidget):
"""Widget for single selection with automatic submission and early
parsing. This widget parses the request when it is created. This
allows its value to be used to decide what other widgets need to be
created in a form. It's a powerful feature but it can be hard to
understand what's going on.
Instance attributes:
value : any
"""
widget_type = "option_select"
def __init__(self, *args, **kwargs):
SingleSelectWidget.__init__(self, *args, **kwargs)
request = get_request()
if request.form:
SingleSelectWidget.parse(self, request)
if self.value is None:
self.value = self.options[0][0]
def render(self, request):
return (SingleSelectWidget.render(self, request) +
htmltext('<noscript>'
'<input type="submit" name="" value="apply" />'
'</noscript>'))
def parse(self, request):
return self.value
def get_current_option(self):
return self.value
class ListWidget (Widget):
"""Widget for lists of objects.
Instance attributes:
value : [any]
"""
widget_type = "list"
def __init__(self, name, value=None,
element_type=None,
element_name="row",
**args):
assert value is None or type(value) is ListType, (
"form value '%s' not a list: got %r" % (name, value))
assert type(element_name) in (StringType, htmltext), (
"form value '%s' element_name not a string: "
"got %r" % (name, element_name))
Widget.__init__(self, name, value)
if element_type is None:
self.element_type = "string"
else:
self.element_type = element_type
self.args = args
self.added_elements_widget = self.create_subwidget(
"hidden", "added_elements")
added_elements = int(self.added_elements_widget.get_current_value() or
'1')
self.add_button = self.create_subwidget(
"submit_button", "add_element",
value="Add %s" % element_name)
if self.add_button.is_submitted():
added_elements += 1
self.added_elements_widget.set_current_value(str(added_elements))
self.element_widgets = []
self.element_count = 0
if self.value is not None:
for element in self.value:
self.add_element(element)
for index in range(added_elements):
self.add_element()
def add_element(self, value=None):
self.element_widgets.append(
self.create_subwidget(self.element_type,
"element_%d" % self.element_count,
value=value,
**self.args))
self.element_count += 1
def render(self, request):
tags = []
for element_widget in self.element_widgets:
tags.append(element_widget.render(request))
tags.append(self.add_button.render(request))
tags.append(self.added_elements_widget.render(request))
return htmltext('<br />\n').join(tags)
def parse(self, request):
self.value = []
for element_widget in self.element_widgets:
value = element_widget.parse(request)
if value is not None:
self.value.append(value)
self.value = self.value or None
return self.value
class CollapsibleListWidget (ListWidget):
"""Widget for lists of objects with associated delete buttons.
CollapsibleListWidget behaves like ListWidget except that each element
is rendered with an associated delete button. Pressing the delete
button will cause the associated element name to be added to a hidden
widget that remembers all deletions until the form is submitted.
Only elements that are not marked as deleted will be rendered and
ultimately added to the value of the widget.
Instance attributes:
value : [any]
"""
widget_type = "collapsible_list"
def __init__(self, name, value=None, element_name="row", **args):
self.name = name
self.element_name = element_name
self.deleted_elements_widget = self.create_subwidget(
"hidden", "deleted_elements")
self.element_delete_buttons = []
self.deleted_elements = (
self.deleted_elements_widget.get_current_value() or '')
ListWidget.__init__(self, name, value=value,
element_name=element_name,
**args)
def add_element(self, value=None):
element_widget_name = "element_%d" % self.element_count
if self.deleted_elements.find(element_widget_name) == -1:
delete_button = self.create_subwidget(
"submit_button", "delete_" + element_widget_name,
value="Delete %s" % self.element_name)
if delete_button.is_submitted():
self.element_count += 1
self.deleted_elements += element_widget_name
self.deleted_elements_widget.set_current_value(
self.deleted_elements)
else:
self.element_delete_buttons.append(delete_button)
ListWidget.add_element(self, value=value)
else:
self.element_count += 1
def render(self, request):
tags = []
for element_widget, element_delete_button in zip(
self.element_widgets, self.element_delete_buttons):
if self.deleted_elements.find(element_widget.name) == -1:
tags.append(element_widget.render(request) +
element_delete_button.render(request))
tags.append(self.add_button.render(request))
tags.append(self.added_elements_widget.render(request))
tags.append(self.deleted_elements_widget.render(request))
return htmltext('<br />\n').join(tags)
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