Added Period as the template period helper, and changed PeriodParser to the inner class Period.Parser.

accounting/views.py

@@ -18,6 +18,7 @@
 """The view controllers of the accounting application.
 
 """
+from datetime import date
 
 from django.http import HttpResponseRedirect, HttpResponse
 
@@ -25,11 +26,12 @@ from django.urls import reverse
 from django.utils import dateformat
 from django.utils.decorators import method_decorator
 from django.utils.timezone import localdate
+from django.utils.translation import get_language
 from django.views import generic
 from django.views.decorators.http import require_GET
 
 from accounting.models import Record
-from mia_core.period import PeriodParser
+from mia_core.period import Period
 from mia import settings
 from mia_core.digest_auth import digest_login_required
 from mia_core.utils import UrlBuilder, Pagination, \
@@ -70,12 +72,12 @@ class BaseReportView(generic.ListView):
     Attributes:
         page_no (int): The specified page number
         page_size (int): The specified page size
-        period_parser (PeriodParser): The period parser
+        period (Period): The template period helper
     """
     page_no = None
     page_size = None
     pagination = None
-    period_parser = None
+    period = None
 
     def get(self, request, *args, **kwargs):
         """Adds object_list to the context.
@@ -125,7 +127,7 @@ class BaseReportView(generic.ListView):
 
     def get_context_data(self, **kwargs):
         data = super(BaseReportView, self).get_context_data(**kwargs)
-        data["period"] = self.period_parser
+        data["period"] = self.period
         data["pagination_links"] = self.pagination.links
         return data
 
@@ -142,7 +144,9 @@ class CashReportView(BaseReportView):
         Returns:
             List[Record]: The accounting records for the cash report
         """
-        self.period_parser = PeriodParser(self.kwargs["period_spec"])
+        self.period = Period(
+            get_language(), date(2000, 1, 1), date(2030, 12, 31),
+            self.kwargs["period_spec"])
         if self.kwargs["subject_code"] == "0":
             records = Record.objects.raw(
                 """SELECT r.*
@@ -174,7 +178,7 @@ ORDER BY
   t.ord,
   CASE WHEN is_credit THEN 1 ELSE 2 END,
   r.ord""",
-                [self.period_parser.start, self.period_parser.end])
+                [self.period.start, self.period.end])
         else:
             records = Record.objects.raw(
                 """SELECT r.*
@@ -200,8 +204,8 @@ ORDER BY
   t.ord,
   CASE WHEN is_credit THEN 1 ELSE 2 END,
   r.ord""",
-                [self.period_parser.start,
+                [self.period.start,
-                 self.period_parser.end,
+                 self.period.end,
                  self.kwargs["subject_code"] + "%",
                  self.kwargs["subject_code"] + "%"])
         self.pagination = Pagination(

mia_core/period.py

@@ -22,13 +22,303 @@
 import re
 from datetime import date, timedelta
 
+from django.core.serializers.json import DjangoJSONEncoder
 from django.template import defaultfilters
 from django.utils import dateformat
 from django.utils.timezone import localdate
-from django.utils.translation import gettext, pgettext
+from django.utils.translation import gettext
 
 
-class PeriodParser:
+class Period:
+    """The template helper for the period chooser.
+
+    Args:
+        language (str): The current language.
+        data_start (date): The available first day of the data.
+        data_end (date): The available last day of the data.
+        spec (str): The current period specification
+
+    Attributes:
+        spec (date): The currently-working period specification.
+        start (date): The start day of the currently-specified period.
+        end (date): The end day of the currently-specified period.
+        description (str): The description of the currently-specified
+                           period.
+        this_month (str): The specification of this month.
+        last_month (str): The specification of last month.
+        since_last_month (str): The specification since last month.
+        has_months_to_choose (bool): Whether there are months to
+                                     choose besides this month and
+                                     last month.
+        chosen_month (bool): The specification of the chosen month,
+                             or None if the current period is not a
+                             month or is out of available data range.
+        this_year (str): The specification of this year.
+        last_year (str): The specification of last year.
+        has_years_to_choose (bool): Whether there are years to
+                                    choose besides this year and
+                                    last year.
+        years_to_choose (list[str]): This specification of the
+                                     available years to choose,
+                                     besides this year and last year.
+        today (str): The specification of today.
+        yesterday (str): The specification of yesterday.
+        chosen_start (str): The specification of the first day of the
+                            specified period, as the default date for
+                            the single-day chooser.
+        has_days_to_choose (bool): Whether there is a day range to
+                                   choose.
+        data_start (str): The specification of the available first day.
+        data_end (str): The specification of the available last day.
+        chosen_start (str): The specification of the first day of the
+                            specified period
+        chosen_end (str): The specification of the last day of the
+                          specified period
+        month_picker_params (str): The month-picker parameters, as a
+                                   JSON text string
+    """
+    _language = None
+    _data_start = None
+    _data_end = None
+    _period = None
+
+    def __init__(self, language, data_start, data_end, spec):
+        self._language = language
+        self._data_start = data_start
+        self._data_end = data_end
+        self._period = self.Parser(spec)
+
+    @property
+    def spec(self):
+        return self._period.spec
+
+    @property
+    def start(self):
+        return self._period.start
+
+    @property
+    def end(self):
+        return self._period.end
+
+    @property
+    def description(self):
+        return self._period.description
+
+    @staticmethod
+    def _get_last_month_start():
+        """Returns the first day of the last month.
+
+        Returns:
+            date: The first day of the last month.
+        """
+        today = localdate()
+        month = today.month - 1
+        year = today.year
+        if month < 1:
+            month = 12
+            year = year - 1
+        return date(year, month, 1)
+
+    @staticmethod
+    def _get_next_month_start():
+        """Returns the first day of the next month.
+
+        Returns:
+            date: The first day of the next month.
+        """
+        today = localdate()
+        month = today.month + 1
+        year = today.year
+        if month > 12:
+            month = 1
+            year = year + 1
+        return date(year, month, 1)
+
+    @property
+    def this_month(self):
+        if self._data_start is None:
+            return None
+        today = localdate()
+        first_month_start = date(
+            self._data_start.year, self._data_start.month, 1)
+        if today < first_month_start:
+            return None
+        return dateformat.format(today, "Y-m")
+
+    @property
+    def last_month(self):
+        if self._data_start is None:
+            return None
+        last_month_start = self._get_last_month_start()
+        first_month_start = date(
+            self._data_start.year, self._data_start.month, 1)
+        if last_month_start < first_month_start:
+            return None
+        return dateformat.format(last_month_start, "Y-m")
+
+    @property
+    def since_last_month(self):
+        last_month = self.last_month
+        if last_month is None:
+            return None
+        return self.last_month + "-"
+
+    @property
+    def has_months_to_choose(self):
+        if self._data_start is None:
+            return None
+        if self._data_start < self._get_last_month_start():
+            return True
+        if self._data_end >= self._get_next_month_start():
+            return True
+        return False
+
+    @property
+    def chosen_month(self):
+        if self._data_start is None:
+            return None
+        m = re.match("^[0-9]{4}-[0-2]{2}", self._period.spec)
+        if m is None:
+            return None
+        if self._period.end < self._data_start:
+            return None
+        if self._period.start > self._data_end:
+            return None
+        return self._period.spec
+
+    @property
+    def this_year(self):
+        if self._data_start is None:
+            return None
+        this_year = localdate().year
+        if this_year < self._data_start.year:
+            return None
+        return str(this_year)
+
+    @property
+    def last_year(self):
+        if self._data_start is None:
+            return None
+        last_year = localdate().year - 1
+        if last_year < self._data_start.year:
+            return None
+        return str(last_year)
+
+    @property
+    def has_years_to_choose(self):
+        if self._data_start is None:
+            return None
+        this_year = localdate().year
+        if self._data_start.year < this_year - 1:
+            return True
+        if self._data_end.year > this_year:
+            return True
+        return False
+
+    @property
+    def years_to_choose(self):
+        if self._data_start is None:
+            return None
+        this_year = localdate().year
+        before = [str(x) for x in range(
+            self._data_start.year, this_year - 1)]
+        after = [str(x) for x in range(
+            self._data_end.year, this_year, -1)]
+        return after + before[::-1]
+
+    def is_chosen_year(self, year):
+        """Returne whether the specified year is the currently-chosen
+        year.
+
+        Args:
+            year (str): the year.
+
+        Returns:
+            bool: True if the year is the currently-chosen year, or
+            False otherwise
+        """
+        if self._period.spec == str(year):
+            return True
+
+    @property
+    def today(self):
+        if self._data_start is None:
+            return None
+        today = localdate()
+        if today < self._data_start or today > self._data_end:
+            return None
+        return dateformat.format(today, "Y-m-d")
+
+    @property
+    def yesterday(self):
+        if self._data_start is None:
+            return None
+        yesterday = localdate() - timedelta(days=1)
+        if yesterday < self._data_start or yesterday > self._data_end:
+            return None
+        return dateformat.format(yesterday, "Y-m-d")
+
+    @property
+    def chosen_day(self):
+        return dateformat.format(self._period.start, "Y-m-d")
+
+    @property
+    def has_days_to_choose(self):
+        if self._data_start is None:
+            return False
+        if self._data_start == self._data_end:
+            return False
+        return True
+
+    @property
+    def first_day(self):
+        if self._data_start is None:
+            return None
+        return dateformat.format(self._data_start, "Y-m-d")
+
+    @property
+    def last_day(self):
+        if self._data_end is None:
+            return None
+        return dateformat.format(self._data_end, "Y-m-d")
+
+    @property
+    def chosen_start(self):
+        if self._data_start is None:
+            return None
+        day = self._period.start \
+            if self._period.start >= self._data_start \
+            else self._data_start
+        return dateformat.format(day, "Y-m-d")
+
+    @property
+    def chosen_end(self):
+        if self._data_end is None:
+            return None
+        day = self._period.end \
+            if self._period.end <= self._data_end \
+            else self._data_end
+        return dateformat.format(day, "Y-m-d")
+
+    @property
+    def month_picker_params(self):
+        if self._data_start is None:
+            return None
+        if self._language == "zh-Hant":
+            locale = "zh_TW"
+        elif self._language == "zh-Hans":
+            locale = "zh_CN"
+        else:
+            locale = self._language.replace("-", "_")
+        start = date(self._data_start.year, self._data_start.month, 1)
+        return DjangoJSONEncoder().encode({
+            "locale": locale,
+            "minDate": start,
+            "maxDate": self._data_end,
+            "defaultDate": self.chosen_month,
+        })
+
+    class Parser:
         """The period parser.
 
         Args:
@@ -107,7 +397,9 @@ class PeriodParser:
             if m is not None:
                 try:
                     self.start = date(
-                    int(m.group(1)), int(m.group(2)), int(m.group(3)))
+                        int(m.group(1)),
+                        int(m.group(2)),
+                        int(m.group(3)))
                 except ValueError:
                     self.invalid_period()
                     return
@@ -121,9 +413,13 @@ class PeriodParser:
             if m is not None:
                 try:
                     self.start = date(
-                    int(m.group(1)), int(m.group(2)), int(m.group(3)))
+                        int(m.group(1)),
+                        int(m.group(2)),
+                        int(m.group(3)))
                     self.end = date(
-                    int(m.group(4)), int(m.group(5)), int(m.group(6)))
+                        int(m.group(4)),
+                        int(m.group(5)),
+                        int(m.group(6)))
                 except ValueError:
                     self.invalid_period()
                     return
@@ -162,7 +458,8 @@ class PeriodParser:
             self.invalid_period()
 
         def invalid_period(self):
-        """Sets the period when the period specification is invalid.
+            """Sets the period when the period specification is
+            invalid.
             """
             self.error = gettext("Invalid period.")
             today = localdate()