Files
edx-platform/xmodule/fields.py

303 lines
11 KiB
Python

# lint-amnesty, pylint: disable=missing-module-docstring
import datetime
import logging
import re
import time
import dateutil.parser
from pytz import UTC
from xblock.fields import JSONField
from xblock.scorable import Score
log = logging.getLogger(__name__)
class Date(JSONField):
'''
Date fields know how to parse and produce json (iso) compatible formats. Converts to tz aware datetimes.
'''
# See note below about not defaulting these
CURRENT_YEAR = datetime.datetime.now(UTC).year
PREVENT_DEFAULT_DAY_MON_SEED1 = datetime.datetime(CURRENT_YEAR, 1, 1, tzinfo=UTC)
PREVENT_DEFAULT_DAY_MON_SEED2 = datetime.datetime(CURRENT_YEAR, 2, 2, tzinfo=UTC)
MUTABLE = False
def _parse_date_wo_default_month_day(self, field):
"""
Parse the field as an iso string but prevent dateutils from defaulting the day or month while
allowing it to default the other fields.
"""
# It's not trivial to replace dateutil b/c parsing timezones as Z, +03:30, -400 is hard in python
# however, we don't want dateutil to default the month or day (but some tests at least expect
# us to default year); so, we'll see if dateutil uses the defaults for these the hard way
result = dateutil.parser.parse(field, default=self.PREVENT_DEFAULT_DAY_MON_SEED1)
result_other = dateutil.parser.parse(field, default=self.PREVENT_DEFAULT_DAY_MON_SEED2)
if result != result_other:
log.warning(f"Field {self.name} is missing month or day")
return None
if result.tzinfo is None:
result = result.replace(tzinfo=UTC)
return result
def from_json(self, field): # lint-amnesty, pylint: disable=arguments-differ
"""
Parse an optional metadata key containing a time: if present, complain
if it doesn't parse.
Return None if not present or invalid.
"""
if field is None:
return field
elif field == "":
return None
elif isinstance(field, str):
return self._parse_date_wo_default_month_day(field)
elif isinstance(field, int) or isinstance(field, float): # lint-amnesty, pylint: disable=consider-merging-isinstance
return datetime.datetime.fromtimestamp(field / 1000, UTC)
elif isinstance(field, time.struct_time):
return datetime.datetime.fromtimestamp(time.mktime(field), UTC)
elif isinstance(field, datetime.datetime):
return field
else:
msg = "Field {} has bad value '{}'".format(
self.name, field)
raise TypeError(msg)
def to_json(self, value):
"""
Convert a time struct to a string
"""
if value is None:
return None
if isinstance(value, time.struct_time):
# struct_times are always utc
return time.strftime('%Y-%m-%dT%H:%M:%SZ', value)
elif isinstance(value, datetime.datetime):
if value.tzinfo is None or value.utcoffset().total_seconds() == 0:
if value.year < 1900:
# strftime doesn't work for pre-1900 dates, so use
# isoformat instead
return value.isoformat()
# isoformat adds +00:00 rather than Z
return value.strftime('%Y-%m-%dT%H:%M:%SZ')
else:
return value.isoformat()
else:
raise TypeError(f"Cannot convert {value!r} to json")
enforce_type = from_json
TIMEDELTA_REGEX = re.compile(r'^((?P<days>\d+?) day(?:s?))?(\s)?((?P<hours>\d+?) hour(?:s?))?(\s)?((?P<minutes>\d+?) minute(?:s)?)?(\s)?((?P<seconds>\d+?) second(?:s)?)?$') # lint-amnesty, pylint: disable=line-too-long
class Timedelta(JSONField): # lint-amnesty, pylint: disable=missing-class-docstring
# Timedeltas are immutable, see http://docs.python.org/2/library/datetime.html#available-types
MUTABLE = False
def from_json(self, time_str): # lint-amnesty, pylint: disable=arguments-differ
"""
time_str: A string with the following components:
<D> day[s] (optional)
<H> hour[s] (optional)
<M> minute[s] (optional)
<S> second[s] (optional)
Returns a datetime.timedelta parsed from the string
"""
if time_str is None:
return None
if isinstance(time_str, datetime.timedelta):
return time_str
parts = TIMEDELTA_REGEX.match(time_str)
if not parts:
return
parts = parts.groupdict()
time_params = {}
for (name, param) in parts.items():
if param:
time_params[name] = int(param)
return datetime.timedelta(**time_params)
def to_json(self, value):
if value is None:
return None
values = []
for attr in ('days', 'hours', 'minutes', 'seconds'):
cur_value = getattr(value, attr, 0)
if cur_value > 0:
values.append("%d %s" % (cur_value, attr))
return ' '.join(values)
def enforce_type(self, value):
"""
Ensure that when set explicitly the Field is set to a timedelta
"""
if isinstance(value, datetime.timedelta) or value is None:
return value
return self.from_json(value)
class RelativeTime(JSONField):
"""
Field for start_time and end_time video block properties.
It was decided, that python representation of start_time and end_time
should be python datetime.timedelta object, to be consistent with
common time representation.
At the same time, serialized representation should be "HH:MM:SS"
This format is convenient to use in XML (and it is used now),
and also it is used in frond-end studio editor of video block as format
for start and end time fields.
In database we previously had float type for start_time and end_time fields,
so we are checking it also.
Python object of RelativeTime is datetime.timedelta.
JSONed representation of RelativeTime is "HH:MM:SS"
"""
# Timedeltas are immutable, see http://docs.python.org/2/library/datetime.html#available-types
MUTABLE = False
@classmethod
def isotime_to_timedelta(cls, value):
"""
Validate that value in "HH:MM:SS" format and convert to timedelta.
Validate that user, that edits XML, sets proper format, and
that max value that can be used by user is "23:59:59".
"""
try:
obj_time = time.strptime(value, '%H:%M:%S')
except ValueError as e:
raise ValueError( # lint-amnesty, pylint: disable=raise-missing-from
"Incorrect RelativeTime value {!r} was set in XML or serialized. "
"Original parse message is {}".format(value, str(e))
)
return datetime.timedelta(
hours=obj_time.tm_hour,
minutes=obj_time.tm_min,
seconds=obj_time.tm_sec
)
def from_json(self, value):
"""
Convert value is in 'HH:MM:SS' format to datetime.timedelta.
If not value, returns 0.
If value is float (backward compatibility issue), convert to timedelta.
"""
if not value:
return datetime.timedelta(seconds=0)
if isinstance(value, datetime.timedelta):
return value
# We've seen serialized versions of float in this field
if isinstance(value, float):
return datetime.timedelta(seconds=value)
if isinstance(value, str):
return self.isotime_to_timedelta(value)
msg = f"RelativeTime Field {self.name} has bad value '{value!r}'"
raise TypeError(msg)
def to_json(self, value):
"""
Convert datetime.timedelta to "HH:MM:SS" format.
If not value, return "00:00:00"
Backward compatibility: check if value is float, and convert it. No exceptions here.
If value is not float, but is exceed 23:59:59, raise exception.
"""
if not value:
return "00:00:00"
if isinstance(value, float): # backward compatibility
value = min(value, 86400)
return self.timedelta_to_string(datetime.timedelta(seconds=value))
if isinstance(value, datetime.timedelta):
if value.total_seconds() > 86400: # sanity check
raise ValueError(
"RelativeTime max value is 23:59:59=86400.0 seconds, "
"but {} seconds is passed".format(value.total_seconds())
)
return self.timedelta_to_string(value)
raise TypeError(f"RelativeTime: cannot convert {value!r} to json")
def timedelta_to_string(self, value):
"""
Makes first 'H' in str representation non-optional.
str(timedelta) has [H]H:MM:SS format, which is not suitable
for front-end (and ISO time standard), so we force HH:MM:SS format.
"""
stringified = str(value)
if len(stringified) == 7:
stringified = '0' + stringified
return stringified
def enforce_type(self, value):
"""
Ensure that when set explicitly the Field is set to a timedelta
"""
if isinstance(value, datetime.timedelta) or value is None:
return value
return self.from_json(value)
class ScoreField(JSONField):
"""
Field for blocks that need to store a Score. XBlocks that implement
the ScorableXBlockMixin may need to store their score separately
from their problem state, specifically for use in staff override
of problem scores.
"""
MUTABLE = False
def from_json(self, value):
if value is None:
return value
if isinstance(value, Score):
return value
if set(value) != {'raw_earned', 'raw_possible'}:
raise TypeError('Scores must contain only a raw earned and raw possible value. Got {}'.format(
set(value)
))
raw_earned = value['raw_earned']
raw_possible = value['raw_possible']
if raw_possible < 0:
raise ValueError(
'Error deserializing field of type {}: Expected a positive number for raw_possible, got {}.'.format(
self.display_name,
raw_possible,
)
)
if not (0 <= raw_earned <= raw_possible): # lint-amnesty, pylint: disable=superfluous-parens
raise ValueError(
'Error deserializing field of type {}: Expected raw_earned between 0 and {}, got {}.'.format(
self.display_name,
raw_possible,
raw_earned
)
)
return Score(raw_earned, raw_possible)
enforce_type = from_json