"""
Parser for HTML forms, that fills in defaults and errors. See
``render``.
"""
import HTMLParser
import cgi
import re
from htmlentitydefs import name2codepoint
__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'):
"""
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 ```` 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 `` ``.
If ``text_as_default`` is true (default false) then ```` 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.
"""
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,
error_class=error_class,
)
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.html, self.text)
def __html__(self):
return self.html
def html_quote(v):
if v is None:
return ''
elif hasattr(v, '__html__'):
return v.__html__()
elif isinstance(v, basestring):
return cgi.escape(v, 1)
else:
# @@: Should this be unicode(v) or str(v)?
return cgi.escape(str(v), 1)
def default_formatter(error):
"""
Formatter that escapes the error, wraps the error in a span with
class ``error-message``, and adds a `` ``
"""
return '%s \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 `` ``
"""
error = html_quote(error)
error = error.replace('\n', ' \n')
return error
class FillingParser(HTMLParser.HTMLParser):
r"""
Fills HTML with default values, as in a form.
Examples::
>>> defaults = {'name': 'Bob Jones',
... 'occupation': 'Crazy Cultist',
... 'address': '14 W. Canal\nNew Guinea',
... 'living': 'no',
... 'nice_guy': 0}
>>> parser = FillingParser(defaults)
>>> parser.feed('\
... \
... \
... ')
>>> print parser.text()
"""
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):
HTMLParser.HTMLParser.__init__(self)
self._content = []
self.source = None
self.lines = None
self.source_pos = None
self.defaults = defaults
self.in_textarea = 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
def feed(self, data):
self.data_is_str = isinstance(data, str)
self.source = data
self.lines = data.split('\n')
self.source_pos = 1, 0
if self.listener:
self.listener.reset()
HTMLParser.HTMLParser.feed(self, data)
def close(self):
self.handle_misc(None)
HTMLParser.HTMLParser.close(self)
unused_errors = self.errors.copy()
for key in self.used_errors.keys():
if unused_errors.has_key(key):
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 = '\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 unused.has_key(key):
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
try:
self._text = ''.join([
t for t in self._content if not isinstance(t, tuple)])
except UnicodeDecodeError, e:
if self.data_is_str:
e.reason += (
" the form was passed in as an encoded string, but "
"some data or error messages were unicode strings; "
"the form should be passed in as a unicode string")
else:
e.reason += (
" the form was passed in as an unicode string, but "
"some data or error message was an encoded string; "
"the data and error messages should be passed in as "
"unicode strings")
raise
def add_key(self, key):
self.used_keys[key] = 1
_entityref_re = re.compile('&([a-zA-Z][-.a-zA-Z\d]*);')
_charref_re = re.compile('&#(\d+|[xX][a-fA-F\d]+);')
def unescape(self, s):
s = self._entityref_re.sub(self._sub_entityref, s)
s = self._charref_re.sub(self._sub_charref, s)
return s
def _sub_entityref(self, match):
name = match.group(1)
if name not in name2codepoint:
# If we don't recognize it, pass it through as though it
# wasn't an entity ref at all
return match.group(0)
return unichr(name2codepoint[name])
def _sub_charref(self, match):
num = match.group(1)
if num.lower().startswith('x'):
num = int(num[1:], 16)
else:
num = int(num)
return unichr(num)
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_misc(self, whatever):
self.write_pos()
handle_charref = handle_misc
handle_entityref = handle_misc
handle_data = handle_misc
handle_comment = handle_misc
handle_decl = handle_misc
handle_pi = handle_misc
unknown_decl = handle_misc
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 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 required if not contained in "
" (%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')
self.write_marker(name)
value = self.defaults.get(name)
if self.add_attributes.has_key(name):
for attr_name, attr_value in self.add_attributes[name].items():
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:
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':
selected = False
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 str(value) == self.get_attr(attrs, 'value'):
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 == 'file':
pass # don't skip next
elif t == 'password':
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 t == 'image':
self.set_attr(attrs, 'src', value or
self.get_attr(attrs, 'src', ''))
self.write_tag('input', attrs, startend)
self.skip_next = True
self.add_key(name)
elif t == 'submit' or t == 'reset' or t == '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 : %s (pos: %s)" \
% (t, self.getpos())
def handle_textarea(self, attrs):
name = self.get_attr(attrs, 'name')
self.write_marker(name)
if (self.error_class
and self.errors.get(name)):
self.add_class(attrs, self.error_class)
self.write_tag('textarea', attrs)
value = self.defaults.get(name, '')
self.write_text(html_quote(value))
self.write_text('')
self.in_textarea = True
self.add_key(name)
def handle_end_textarea(self):
self.in_textarea = False
self.skip_next = True
def handle_select(self, attrs):
name = self.get_attr(attrs, 'name', False)
if name:
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.in_select = None
def handle_option(self, attrs):
assert self.in_select is not None, (
"