Added date and time field/widget for Dexterity contents (#1903)

* Implemented datetime field

* Custom setter for datetime field

* Implemented datetime widget

* Handle timezones

* Added datetime API

* Always localize the date on field level

* Datetime widget refactored to use the date API

* Extended API

* Check if timezone is callable

This can be the case when the `default_timezone` is set through
a directive on the widget, e.g.:

  from plone.app.event.base import default_timezone

* Changelog updated

* Updated scrutinizer config

* Added API function to generate a POSIX timestamp

* Added from_timestamp API function

* Added ISO format API

* Handle Python date objects

* Dropped get_min/get_max methods

* Test fixed for TZ

* Fixed datetimewidget display value

* Test fixture

* Fixed test

Author: ramonski

.scrutinizer.yml

@@ -21,21 +21,18 @@ filter:
 
 build:
   environment:
-    python: 2.7.9
+    python: 2.7.18
 
   dependencies:
     before:
-      - pip install -v pip==19.3.1
-      - pip install -v setuptools==44.1.1
-      - pip install -v zc.buildout==2.13.3
       - pip install virtualenv
       - pip install -r requirements.txt
-      - /home/scrutinizer/.pyenv/versions/2.7.9/bin/buildout -v
-      - mv -v /home/scrutinizer/build/develop-eggs/* /home/scrutinizer/.pyenv/versions/2.7.9/lib/python2.7/site-packages/
-      - mv -v /home/scrutinizer/build/eggs/*.egg /home/scrutinizer/.pyenv/versions/2.7.9/lib/python2.7/site-packages/
+      - /home/scrutinizer/.pyenv/versions/2.7.18/bin/buildout -v
+      - mv -v /home/scrutinizer/build/develop-eggs/* /home/scrutinizer/.pyenv/versions/2.7.18/lib/python2.7/site-packages/
+      - mv -v /home/scrutinizer/build/eggs/*.egg /home/scrutinizer/.pyenv/versions/2.7.18/lib/python2.7/site-packages/
 
   nodes:
     analysis:
       tests:
         override:
-          - py-scrutinizer-run
+          - py-scrutinizer-run

CHANGES.rst

@@ -4,6 +4,7 @@ Changelog
 2.0.1 (unreleased)
 ------------------
 
+- #1903 Added date and time field/widget for Dexterity contents
 - #1901 Ensure `get_tool` returns a tool when a name is set as the default param
 - #1900 Fix snapshot listing fails on orphan catalog entries
 - #1897 Support date and number fields copy in sample add form

src/senaite/core/api/dtime.py

@@ -0,0 +1,199 @@
+# -*- coding: utf-8 -*-
+
+import os
+import time
+from datetime import date
+from datetime import datetime
+
+import pytz
+from bika.lims import logger
+from DateTime import DateTime
+
+
+def is_d(dt):
+    """Check if the date is a Python `date` object
+
+    :param dt: date to check
+    :returns: True when the date is a Python `date`
+    """
+    return type(dt) is date
+
+
+def is_dt(dt):
+    """Check if the date is a Python `datetime` object
+
+    :param dt: date to check
+    :returns: True when the date is a Python `datetime`
+    """
+    return type(dt) is datetime
+
+
+def is_DT(dt):
+    """Check if the date is a Zope `DateTime` object
+
+    :param dt: object to check
+    :returns: True when the object is a Zope `DateTime`
+    """
+    return type(dt) is DateTime
+
+
+def is_date(dt):
+    """Check if the date is a datetime or DateTime object
+
+    :param dt: date to check
+    :returns: True when the object is either a datetime or DateTime
+    """
+    if is_d(dt):
+        return True
+    if is_dt(dt):
+        return True
+    if is_DT(dt):
+        return True
+    return False
+
+
+def is_timezone_naive(dt):
+    """Check if the date is timezone naive
+
+    :param dt: date to check
+    :returns: True when the date has no timezone
+    """
+    if is_d(dt):
+        return True
+    elif is_DT(dt):
+        return dt.timezoneNaive()
+    elif is_dt(dt):
+        return dt.tzinfo is None
+    raise TypeError("Expected a date, got '%r'" % type(dt))
+
+
+def is_timezone_aware(dt):
+    """Check if the date is timezone aware
+
+    :param dt: date to check
+    :returns: True when the date has a timezone
+    """
+    return not is_timezone_naive(dt)
+
+
+def to_DT(dt):
+    """Convert to DateTime
+
+    :param dt: DateTime/datetime/date
+    :returns: DateTime object
+    """
+    if is_DT(dt):
+        return dt
+    elif is_dt(dt):
+        return DateTime(dt.isoformat())
+    elif is_d(dt):
+        dt = datetime(dt.year, dt.month, dt.day)
+        return DateTime(dt.isoformat())
+    raise TypeError("Expected datetime, got '%r'" % type(dt))
+
+
+def to_dt(dt):
+    """Convert to datetime
+
+    :param dt: DateTime/datetime/date
+    :returns: datetime object
+    """
+    if is_DT(dt):
+        return dt.asdatetime()
+    elif is_dt(dt):
+        return dt
+    elif is_d(dt):
+        return datetime(dt.year, dt.month, dt.day)
+    raise TypeError("Expected DateTime, got '%r'" % type(dt))
+
+
+def is_valid_timezone(timezone):
+    """Checks if the timezone is a valid pytz/Olson name
+
+    :param timezone: pytz/Olson timezone name
+    :returns: True when the timezone is a valid zone
+    """
+    try:
+        pytz.timezone(timezone)
+        return True
+    except pytz.UnknownTimeZoneError:
+        return False
+
+
+def get_os_timezone():
+    """Return the default timezone of the system
+
+    :returns: OS timezone or UTC
+    """
+    fallback = "UTC"
+    timezone = None
+    if "TZ" in os.environ.keys():
+        # Timezone from OS env var
+        timezone = os.environ["TZ"]
+    if not timezone:
+        # Timezone from python time
+        zones = time.tzname
+        if zones and len(zones) > 0:
+            timezone = zones[0]
+        else:
+            # Default fallback = UTC
+            logger.warn(
+                "Operating system\'s timezone cannot be found. "
+                "Falling back to UTC.")
+            timezone = fallback
+    if not is_valid_timezone(timezone):
+        return fallback
+    return timezone
+
+
+def to_zone(dt, timezone):
+    """Convert date to timezone
+
+    Adds the timezone for timezone naive datetimes
+
+    :param dt: date object
+    :param timezone: timezone
+    :returns: date converted to timezone
+    """
+    if is_dt(dt):
+        zone = pytz.timezone(timezone)
+        if is_timezone_aware(dt):
+            return dt.astimezone(zone)
+        return zone.localize(dt)
+    if is_DT(dt):
+        # NOTE: This shifts the time according to the TZ offset
+        return dt.toZone(timezone)
+
+
+def to_timestamp(dt):
+    """Generate a Portable Operating System Interface (POSIX) timestamp
+
+    :param dt: date object
+    :returns: timestamp in seconds
+    """
+    timestamp = 0
+    if is_DT(dt):
+        timestamp = dt.timeTime()
+    elif is_dt(dt):
+        timestamp = time.mktime(dt.timetuple())
+    return timestamp
+
+
+def from_timestamp(timestamp):
+    """Generate a datetime object from a POSIX timestamp
+
+    :param timestamp: POSIX timestamp
+    :returns: datetime object
+    """
+
+    return datetime.utcfromtimestamp(timestamp)
+
+
+def to_iso_format(dt):
+    """Convert to ISO format
+    """
+    if is_dt(dt):
+        return dt.isoformat()
+    elif is_DT(dt):
+        return dt.ISO()
+    return None

src/senaite/core/schema/__init__.py

@@ -2,10 +2,13 @@
 
 from zope.interface import classImplementsFirst
 
+from .datetimefield import DatetimeField
 from .fields import IntField
+from .interfaces import IDatetimeField
 from .interfaces import IIntField
 from .uidreferencefield import IUIDReferenceField
 from .uidreferencefield import UIDReferenceField
 
 classImplementsFirst(IntField, IIntField)
 classImplementsFirst(UIDReferenceField, IUIDReferenceField)
+classImplementsFirst(DatetimeField, IDatetimeField)

src/senaite/core/schema/datetimefield.py

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+
+from senaite.core.api import dtime
+from senaite.core.schema.fields import BaseField
+from senaite.core.schema.interfaces import IDatetimeField
+from zope.interface import implementer
+from zope.schema import Datetime
+
+
+def localize(dt, fallback="UTC"):
+    if dtime.is_timezone_naive(dt):
+        zone = dtime.get_os_timezone()
+        if not zone:
+            zone = fallback
+        dt = dtime.to_zone(dt, zone)
+    return dt
+
+
+@implementer(IDatetimeField)
+class DatetimeField(Datetime, BaseField):
+    """A field that handles date and time
+    """
+
+    def set(self, object, value):
+        """Set datetime value
+
+
+        NOTE: we need to ensure timzone aware datetime values,
+              so that also API calls work
+
+        :param object: the instance of the field
+        :param value: datetime value
+        :type value: datetime
+        """
+        if dtime.is_dt(value):
+            value = localize(value)
+        super(DatetimeField, self).set(object, value)
+
+    def get(self, object):
+        """Get the current date
+
+        :param object: the instance of the field
+        :returns: datetime or None
+        """
+        value = super(DatetimeField, self).get(object)
+        if not dtime.is_dt(value):
+            return None
+        return localize(value)
+
+    def _validate(self, value):
+        """Validator when called from form submission
+        """
+        super(DatetimeField, self)._validate(value)

src/senaite/core/schema/datetimefield.txt

@@ -0,0 +1,76 @@
+Datetime field
+==============
+
+The datetime field stores Python datetime values.
+
+
+Running this test from the buildout directory:
+
+    bin/test test_schema_fields -t datetimefield
+
+
+Hints
+
+- z3c.form.converter.txt (Date Data Converter)
+
+
+Test preparation
+----------------
+
+    >>> import sys
+    >>> from bika.lims import api
+    >>> from plone.app.testing import setRoles
+    >>> from plone.app.testing import TEST_USER_ID
+    >>> from plone.app.testing import TEST_USER_NAME
+    >>> from plone.app.testing import TEST_USER_PASSWORD
+
+Helper functions:
+
+    >>> def commit():
+    ...    import transaction; transaction.commit()
+     
+
+Grant required privileges:
+
+    >>> setRoles(portal, TEST_USER_ID, ["Manager",])
+    >>> commit()
+
+Test fixture:
+
+    >>> import os
+    >>> os.environ["TZ"] = "CET"
+
+
+Using the field
+---------------
+
+The field can be used much like any other field:
+
+    >>> from zope.interface import Interface, implementer
+    >>> from senaite.core.schema import DatetimeField
+
+    >>> class IContent(Interface):
+    ...     date = DatetimeField(title=u"Date")
+
+    >>> field = IContent['date']
+    >>> field
+    <senaite.core.schema.datetimefield.DatetimeField object at ...>
+
+    >>> from persistent import Persistent
+    >>> @implementer(IContent)
+    ... class Content(Persistent):
+    ...     def __init__(self, date=None):
+    ...         self.date = date
+
+
+    >>> from datetime import datetime
+    >>> datestring = "2030-12-24"
+    >>> date = datetime.strptime(datestring, "%Y-%m-%d")
+    >>> content = Content()
+
+
+Set a value through the field:
+
+    >>> field.set(content, date)
+    >>> field.get(content)
+    datetime.datetime(2030, 12, 24, 0, 0, tzinfo=<DstTzInfo 'CET' CET+1:00:00 STD>)