Add "falafel" custom date/time field type and widget

finally able to edit datetime fields, but feels like a lot of
assumptions to make, just to determine time zone..so keeping naive UTC
on the backend still, and naive local on the frontend

in general this needs more polish, but is a start..

tailbone/forms/__init__.py

@@ -2,7 +2,7 @@
 ################################################################################
 #
 #  Rattail -- Retail Software Framework
-#  Copyright © 2010-2018 Lance Edgar
+#  Copyright © 2010-2023 Lance Edgar
 #
 #  This file is part of Rattail.
 #
@@ -24,8 +24,7 @@
 Forms Library
 """
 
-from __future__ import unicode_literals, absolute_import
-
-from . import types
+# nb. import widgets before types, b/c types may refer to widgets
 from . import widgets
+from . import types
 from .core import Form, SimpleFileImport

tailbone/forms/core.py

@@ -590,8 +590,18 @@ class Form(object):
             self.schema[key] = node
 
     def set_type(self, key, type_, **kwargs):
+
         if type_ == 'datetime':
             self.set_renderer(key, self.render_datetime)
+
+        elif type_ == 'datetime_falafel':
+            self.set_renderer(key, self.render_datetime)
+            self.set_node(key, types.FalafelDateTime(request=self.request))
+            if kwargs.get('helptext'):
+                app = self.request.rattail_config.get_app()
+                timezone = app.get_timezone()
+                self.set_helptext(key, f"NOTE: all times are local to {timezone}")
+
         elif type_ == 'datetime_local':
             self.set_renderer(key, self.render_datetime_local)
         elif type_ == 'date_plain':
@@ -871,6 +881,9 @@ class Form(object):
             if field.cstruct is colander.null:
                 return '[]'
 
+        if isinstance(field.schema.typ, types.FalafelDateTime):
+            return field.cstruct
+
         try:
             return self.jsonify_value(field.cstruct)
         except Exception as error:

tailbone/forms/types.py

@@ -26,6 +26,7 @@ Form Schema Types
 
 import re
 import datetime
+import json
 
 from rattail.db import model
 from rattail.gpc import GPC
@@ -33,6 +34,7 @@ from rattail.gpc import GPC
 import colander
 
 from tailbone.db import Session
+from tailbone.forms import widgets
 
 
 class JQueryTime(colander.Time):
@@ -72,6 +74,50 @@ class DateTimeBoolean(colander.Boolean):
             return datetime.datetime.utcnow()
 
 
+class FalafelDateTime(colander.DateTime):
+    """
+    Custom schema node type for rattail UTC datetimes
+    """
+    widget_maker = widgets.FalafelDateTimeWidget
+
+    def __init__(self, *args, **kwargs):
+        request = kwargs.pop('request')
+        super().__init__(*args, **kwargs)
+        self.request = request
+
+    def serialize(self, node, appstruct):
+        if not appstruct:
+            return colander.null
+
+        # cant use isinstance; dt subs date
+        if type(appstruct) is datetime.date:
+            appstruct = datetime.datetime.combine(appstruct, datetime.time())
+
+        if not isinstance(appstruct, datetime.datetime):
+            raise colander.Invalid(node, f'"{appstruct}" is not a datetime object')
+
+        if appstruct.tzinfo is None:
+            appstruct = appstruct.replace(tzinfo=self.default_tzinfo)
+
+        app = self.request.rattail_config.get_app()
+        dt = app.localtime(appstruct, from_utc=True)
+
+        return json.dumps({
+            'date': str(dt.date()),
+            'time': str(dt.time()),
+        })
+
+    def deserialize(self, node, cstruct):
+        if not cstruct:
+            return colander.null
+
+        app = self.request.rattail_config.get_app()
+        result = datetime.datetime.strptime(cstruct, '%Y-%m-%dT%H:%M:%S')
+        result = app.localtime(result)
+        result = app.make_utc(result)
+        return result
+
+
 class GPCType(colander.SchemaType):
     """
     Schema type for product GPC data.

tailbone/forms/widgets.py

@@ -33,7 +33,6 @@ from deform import widget as dfwidget
 from webhelpers2.html import tags, HTML
 
 from tailbone.db import Session
-from tailbone.forms.types import ProductQuantity
 
 
 class ReadonlyWidget(dfwidget.HiddenWidget):
@@ -119,6 +118,8 @@ class CasesUnitsWidget(dfwidget.Widget):
         return field.renderer(template, **values)
 
     def deserialize(self, field, pstruct):
+        from tailbone.forms.types import ProductQuantity
+
         if pstruct is colander.null:
             return colander.null
 
@@ -235,6 +236,13 @@ class JQueryTimeWidget(dfwidget.TimeInputWidget):
     )
 
 
+class FalafelDateTimeWidget(dfwidget.DateTimeInputWidget):
+    """
+    Custom widget for rattail UTC datetimes
+    """
+    template = 'datetime_falafel'
+
+
 class JQueryAutocompleteWidget(dfwidget.AutocompleteInputWidget):
     """ 
     Uses the jQuery autocomplete plugin, instead of whatever it is deform uses

tailbone/static/js/tailbone.buefy.timepicker.js

@@ -9,15 +9,55 @@ const TailboneTimepicker = {
         'placeholder="Click to select ..."',
         'icon-pack="fas"',
         'icon="clock"',
+        ':value="value ? parseTime(value) : null"',
         'hour-format="12"',
+        '@input="timeChanged"',
+        ':time-formatter="formatTime"',
         '>',
         '</b-timepicker>'
     ].join(' '),
 
     props: {
         name: String,
-        id: String
+        id: String,
+        value: String,
+    },
+
+    methods: {
+
+        formatTime(time) {
+            if (time === null) {
+                return null
             }
+
+            let h = time.getHours()
+            let m = time.getMinutes()
+            let s = time.getSeconds()
+
+            h = h < 10 ? '0' + h : h
+            m = m < 10 ? '0' + m : m
+            s = s < 10 ? '0' + s : s
+
+            return h + ':' + m + ':' + s
+        },
+
+        parseTime(time) {
+
+            if (time.getHours) {
+                return time
+            }
+
+            let found = time.match(/^(\d\d):(\d\d):\d\d$/)
+            if (found) {
+                return new Date(null, null, null,
+                                parseInt(found[1]), parseInt(found[2]))
+            }
+        },
+
+        timeChanged(time) {
+            this.$emit('input', time)
+        },
+    },
 }
 
 Vue.component('tailbone-timepicker', TailboneTimepicker)

tailbone/templates/deform/datetime_falafel.pt

@@ -0,0 +1,23 @@
+<div tal:omit-tag=""
+     tal:define="name name|field.name;
+                 vmodel vmodel|'field_model_' + name;">
+
+  <b-field grouped>
+    ${field.start_mapping()}
+
+    <b-field label="Date">
+      <tailbone-datepicker name="date"
+                           v-model="${vmodel}.date">
+      </tailbone-datepicker>
+    </b-field>
+
+    <b-field label="Time">
+      <tailbone-timepicker name="time"
+                           v-model="${vmodel}.time">
+      </tailbone-timepicker>
+    </b-field>
+
+    ${field.end_mapping()}
+  </b-field>
+
+</div>