"""
Parser for HTML forms, that fills in defaults and errors. See ``render``.
"""
import re
from formencode.rewritingparser import RewritingParser, html_quote
__all__ = ['render', 'htmlliteral', 'default_formatter',
'none_formatter', 'escape_formatter',
'FillingParser']
def render(form, defaults=None, errors=None, use_all_keys=False,
error_formatters=None, add_attributes=None,
auto_insert_errors=True, auto_error_formatter=None,
text_as_default=False, listener=None, encoding=None,
error_class='error', prefix_error=True,
force_defaults=True):
"""
Render the ``form`` (which should be a string) given the defaults
and errors. Defaults are the values that go in the input fields
(overwriting any values that are there) and errors are displayed
inline in the form (and also effect input classes). Returns the
rendered string.
If ``auto_insert_errors`` is true (the default) then any errors
for which ``<form:error>`` tags can't be found will be put just
above the associated input field, or at the top of the form if no
field can be found.
If ``use_all_keys`` is true, if there are any extra fields from
defaults or errors that couldn't be used in the form it will be an
error.
``error_formatters`` is a dictionary of formatter names to
one-argument functions that format an error into HTML. Some
default formatters are provided if you don't provide this.
``error_class`` is the class added to input fields when there is
an error for that field.
``add_attributes`` is a dictionary of field names to a dictionary
of attribute name/values. If the name starts with ``+`` then the
value will be appended to any existing attribute (e.g.,
``{'+class': ' important'}``).
``auto_error_formatter`` is used to create the HTML that goes
above the fields. By default it wraps the error message in a span
and adds a ``<br>``.
If ``text_as_default`` is true (default false) then ``<input
type=unknown>`` will be treated as text inputs.
``listener`` can be an object that watches fields pass; the only
one currently is in ``htmlfill_schemabuilder.SchemaBuilder``
``encoding`` specifies an encoding to assume when mixing str and
unicode text in the template.
``prefix_error`` specifies if the HTML created by auto_error_formatter is
put before the input control (default) or after the control.
``force_defaults`` specifies if a field default is not given in
the ``defaults`` dictionary then the control associated with the
field should be set as an unsuccessful control. So checkboxes will
be cleared, radio and select controls will have no value selected,
and textareas will be emptied. This defaults to ``True``, which is
appropriate the defaults are the result of a form submission.
"""
if defaults is None:
defaults = {}
if auto_insert_errors and auto_error_formatter is None:
auto_error_formatter = default_formatter
p = FillingParser(
defaults=defaults, errors=errors,
use_all_keys=use_all_keys,
error_formatters=error_formatters,
add_attributes=add_attributes,
auto_error_formatter=auto_error_formatter,
text_as_default=text_as_default,
listener=listener, encoding=encoding,
prefix_error=prefix_error,
error_class=error_class,
force_defaults=force_defaults,
)
p.feed(form)
p.close()
return p.text()
class htmlliteral(object):
def __init__(self, html, text=None):
if text is None:
text = re.sub(r'<.*?>', '', html)
text = html.replace('>', '>')
text = html.replace('<', '<')
text = html.replace('"', '"')
# @@: Not very complete
self.html = html
self.text = text
def __str__(self):
return self.text
def __repr__(self):
return '<%s html=%r text=%r>' % (
self.__class__.__name__, self.html, self.text)
def __html__(self):
return self.html
def default_formatter(error):
"""
Formatter that escapes the error, wraps the error in a span with
class ``error-message``, and adds a ``<br>``
"""
return '<span class="error-message">%s</span><br />\n' % html_quote(error)
def none_formatter(error):
"""
Formatter that does nothing, no escaping HTML, nothin'
"""
return error
def escape_formatter(error):
"""
Formatter that escapes HTML, no more.
"""
return html_quote(error)
def escapenl_formatter(error):
"""
Formatter that escapes HTML, and translates newlines to ``<br>``
"""
error = html_quote(error)
error = error.replace('\n', '<br>\n')
return error
def ignore_formatter(error):
"""
Formatter that emits nothing, regardless of the error.
"""
return ''
class FillingParser(RewritingParser):
r"""
Fills HTML with default values, as in a form.
Examples::
>>> defaults = dict(name='Bob Jones',
... occupation='Crazy Cultist',
... address='14 W. Canal\nNew Guinea',
... living='no',
... nice_guy=0)
>>> parser = FillingParser(defaults)
>>> parser.feed('''<input type="text" name="name" value="fill">
... <select name="occupation"> <option value="">Default</option>
... <option value="Crazy Cultist">Crazy cultist</option> </select>
... <textarea cols="20" style="width: 100%" name="address">
... An address</textarea>
... <input type="radio" name="living" value="yes">
... <input type="radio" name="living" value="no">
... <input type="checkbox" name="nice_guy" checked="checked">''')
>>> parser.close()
>>> print parser.text() # doctest: +NORMALIZE_WHITESPACE
<input type="text" name="name" value="Bob Jones">
<select name="occupation">
<option value="">Default</option>
<option value="Crazy Cultist" selected="selected">Crazy cultist</option>
</select>
<textarea cols="20" style="width: 100%" name="address">14 W. Canal
New Guinea</textarea>
<input type="radio" name="living" value="yes">
<input type="radio" name="living" value="no" checked="checked">
<input type="checkbox" name="nice_guy">
"""
default_encoding = 'utf8'
def __init__(self, defaults, errors=None, use_all_keys=False,
error_formatters=None, error_class='error',
add_attributes=None, listener=None,
auto_error_formatter=None,
text_as_default=False, encoding=None, prefix_error=True,
force_defaults=True):
RewritingParser.__init__(self)
self.source = None
self.lines = None
self.source_pos = None
self.defaults = defaults
self.in_textarea = None
self.skip_textarea = False
self.last_textarea_name = None
self.in_select = None
self.skip_next = False
self.errors = errors or {}
if isinstance(self.errors, (str, unicode)):
self.errors = {None: self.errors}
self.in_error = None
self.skip_error = False
self.use_all_keys = use_all_keys
self.used_keys = {}
self.used_errors = {}
if error_formatters is None:
self.error_formatters = default_formatter_dict
else:
self.error_formatters = error_formatters
self.error_class = error_class
self.add_attributes = add_attributes or {}
self.listener = listener
self.auto_error_formatter = auto_error_formatter
self.text_as_default = text_as_default
self.encoding = encoding
self.prefix_error = prefix_error
self.force_defaults = force_defaults
def str_compare(self, str1, str2):
"""
Compare the two objects as strings (coercing to strings if necessary).
Also uses encoding to compare the strings.
"""
if not isinstance(str1, basestring):
if hasattr(str1, '__unicode__'):
str1 = unicode(str1)
else:
str1 = str(str1)
if type(str1) == type(str2):
return str1 == str2
if isinstance(str1, unicode):
str1 = str1.encode(self.encoding or self.default_encoding)
else:
str2 = str2.encode(self.encoding or self.default_encoding)
return str1 == str2
def close(self):
self.handle_misc(None)
RewritingParser.close(self)
unused_errors = self.errors.copy()
for key in self.used_errors.keys():
if key in unused_errors:
del unused_errors[key]
if self.auto_error_formatter:
for key, value in unused_errors.items():
error_message = self.auto_error_formatter(value)
error_message = '<!-- for: %s -->\n%s' % (key, error_message)
self.insert_at_marker(
key, error_message)
unused_errors = {}
if self.use_all_keys:
unused = self.defaults.copy()
for key in self.used_keys.keys():
if key in unused:
del unused[key]
assert not unused, (
"These keys from defaults were not used in the form: %s"
% unused.keys())
if unused_errors:
error_text = []
for key in unused_errors.keys():
error_text.append("%s: %s" % (key, self.errors[key]))
assert False, (
"These errors were not used in the form: %s" %
', '.join(error_text))
if self.encoding is not None:
new_content = []
for item in self._content:
if isinstance(item, str):
item = item.decode(self.encoding)
new_content.append(item)
self._content = new_content
self._text = self._get_text()
def skip_output(self):
return (self.in_textarea and self.skip_textarea) or self.skip_error
def add_key(self, key):
self.used_keys[key] = 1
def handle_starttag(self, tag, attrs, startend=False):
self.write_pos()
if tag == 'input':
self.handle_input(attrs, startend)
elif tag == 'textarea':
self.handle_textarea(attrs)
elif tag == 'select':
self.handle_select(attrs)
elif tag == 'option':
self.handle_option(attrs)
return
elif tag == 'form:error':
self.handle_error(attrs)
return
elif tag == 'form:iferror':
self.handle_iferror(attrs)
return
else:
return
if self.listener:
self.listener.listen_input(self, tag, attrs)
def handle_endtag(self, tag):
self.write_pos()
if tag == 'textarea':
self.handle_end_textarea()
elif tag == 'select':
self.handle_end_select()
elif tag == 'form:iferror':
self.handle_end_iferror()
def handle_startendtag(self, tag, attrs):
return self.handle_starttag(tag, attrs, True)
def handle_iferror(self, attrs):
name = self.get_attr(attrs, 'name')
notted = False
if name.startswith('not '):
notted = True
name = name.split(None, 1)[1]
assert name, "Name attribute in <iferror> required (%s)" % self.getpos()
self.in_error = name
ok = self.errors.get(name)
if notted:
ok = not ok
if not ok:
self.skip_error = True
self.skip_next = True
def handle_end_iferror(self):
self.in_error = None
self.skip_error = False
self.skip_next = True
def handle_error(self, attrs):
name = self.get_attr(attrs, 'name')
formatter = self.get_attr(attrs, 'format') or 'default'
if name is None:
name = self.in_error
assert name is not None, (
"Name attribute in <form:error> required if not contained in "
"<form:iferror> (%i:%i)" % self.getpos())
error = self.errors.get(name, '')
if error:
error = self.error_formatters[formatter](error)
self.write_text(error)
self.skip_next = True
self.used_errors[name] = 1
def handle_input(self, attrs, startend):
t = (self.get_attr(attrs, 'type') or 'text').lower()
name = self.get_attr(attrs, 'name')
if self.prefix_error:
self.write_marker(name)
value = self.defaults.get(name)
if isinstance(name, unicode) and isinstance(value, str):
value = value.decode(self.encoding or self.default_encoding)
if name in self.add_attributes:
for attr_name, attr_value in self.add_attributes[name].iteritems():
if attr_name.startswith('+'):
attr_name = attr_name[1:]
self.set_attr(attrs, attr_name,
self.get_attr(attrs, attr_name, '') + attr_value)
else:
self.set_attr(attrs, attr_name, attr_value)
if (self.error_class
and self.errors.get(self.get_attr(attrs, 'name'))):
self.add_class(attrs, self.error_class)
if t in ('text', 'hidden'):
if value is None and not self.force_defaults:
value = self.get_attr(attrs, 'value', '')
self.set_attr(attrs, 'value', value)
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif t == 'checkbox':
if self.force_defaults:
selected = False
else:
selected = self.get_attr(attrs, 'checked')
if not self.get_attr(attrs, 'value'):
selected = value
elif self.selected_multiple(value,
self.get_attr(attrs, 'value', '')):
selected = True
if selected:
self.set_attr(attrs, 'checked', 'checked')
else:
self.del_attr(attrs, 'checked')
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif t == 'radio':
if self.str_compare(value, self.get_attr(attrs, 'value', '')):
self.set_attr(attrs, 'checked', 'checked')
elif self.force_defaults or name in self.defaults:
self.del_attr(attrs, 'checked')
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif t == 'password':
if value is None and not self.force_defaults:
value = value or self.get_attr(attrs, 'value', '')
self.set_attr(attrs, 'value', value)
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif t in ('file', 'image'):
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif t in ('submit', 'reset', 'button'):
self.set_attr(attrs, 'value', value or
self.get_attr(attrs, 'value', ''))
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif self.text_as_default:
if value is None:
value = self.get_attr(attrs, 'value', '')
self.set_attr(attrs, 'value', value)
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
else:
assert 0, "I don't know about this kind of <input>: %s (pos: %s)" \
% (t, self.getpos())
if not self.prefix_error:
self.write_marker(name)
def handle_textarea(self, attrs):
name = self.get_attr(attrs, 'name')
if self.prefix_error:
self.write_marker(name)
if (self.error_class
and self.errors.get(name)):
self.add_class(attrs, self.error_class)
value = self.defaults.get(name, '')
if value or self.force_defaults:
self.write_tag('textarea', attrs)
self.write_text(html_quote(value))
self.write_text('</textarea>')
self.skip_textarea = True
self.in_textarea = True
self.last_textarea_name = name
self.add_key(name)
def handle_end_textarea(self):
if self.skip_textarea:
self.skip_textarea = False
else:
self.write_text('</textarea>')
self.in_textarea = False
self.skip_next = True
if not self.prefix_error:
self.write_marker(self.last_textarea_name)
self.last_textarea_name = None
def handle_select(self, attrs):
name = self.get_attr(attrs, 'name', False)
if name and self.prefix_error:
self.write_marker(name)
if (self.error_class
and self.errors.get(name)):
self.add_class(attrs, self.error_class)
self.in_select = self.get_attr(attrs, 'name', False)
self.write_tag('select', attrs)
self.skip_next = True
self.add_key(self.in_select)
def handle_end_select(self):
self.write_text('</select>')
self.skip_next = True
if not self.prefix_error and self.in_select:
self.write_marker(self.in_select)
self.in_select = None
def handle_option(self, attrs):
assert self.in_select is not None, (
"<option> outside of <select>: line %i, column %i"
% self.getpos())
if self.in_select != False:
if self.force_defaults or self.in_select in self.defaults:
if self.selected_multiple(self.defaults.get(self.in_select, ''),
self.get_attr(attrs, 'value', '')):
self.set_attr(attrs, 'selected', 'selected')
self.add_key(self.in_select)
else:
self.del_attr(attrs, 'selected')
self.write_tag('option', attrs)
self.skip_next = True
def selected_multiple(self, obj, value):
"""
Returns true/false if obj indicates that value should be
selected. If obj has a __contains__ method it is used, otherwise
identity is used.
"""
if obj is None:
return value == ""
if isinstance(obj, (str, unicode)):
return obj == value
if hasattr(obj, '__contains__'):
if value in obj:
return True
if hasattr(obj, '__iter__'):
for inner in obj:
if self.str_compare(inner, value):
return True
return self.str_compare(obj, value)
def write_marker(self, marker):
self._content.append((marker,))
def insert_at_marker(self, marker, text):
for i, item in enumerate(self._content):
if item == (marker,):
self._content.insert(i, text)
break
else:
self._content.insert(0, text)
# This can potentially be extended globally
default_formatter_dict = dict(
default=default_formatter,
none=none_formatter,
escape=escape_formatter,
escapenl=escapenl_formatter,
ignore=ignore_formatter)