now() today() timeOfDay() date and time functions

Author: qscgyjqscgyj

.gitignore

@@ -130,3 +130,4 @@ dmypy.json
 
 # Other
 .DS_Store
+.idea/

fhirpathpy/__init__.py

@@ -1,3 +1,4 @@
+from fhirpathpy.engine.invocations.constants import Constants
 from fhirpathpy.parser import parse
 from fhirpathpy.engine import do_eval
 from fhirpathpy.engine.util import arraify, get_data
@@ -14,7 +15,7 @@
 
 
 def apply_parsed_path(resource, parsedPath, context={}, model=None):
-    # constants.reset();
+    Constants.reset()
     dataRoot = arraify(resource)
 
     """
@@ -48,33 +49,33 @@ def visit(node):
 
 
 def evaluate(resource, path, context={}, model=None):
-    """ 
+    """
     Evaluates the "path" FHIRPath expression on the given resource, using data
     from "context" for variables mentioned in the "path" expression.
 
-    Parameters: 
+    Parameters:
     resource (dict|list): FHIR resource, bundle as js object or array of resources This resource will be modified by this function to add type information.
     path (string): fhirpath expression, sample 'Patient.name.given'
     context (dict): a hash of variable name/value pairs.
     model (dict): The "model" data object specific to a domain, e.g. R4.
 
-    Returns: 
-    int: Description of return value 
+    Returns:
+    int: Description of return value
 
     """
     node = parse(path)
     return apply_parsed_path(resource, node, context, model)
 
 
 def compile(path, model=None):
-    """ 
+    """
     Returns a function that takes a resource and an optional context hash (see
     "evaluate"), and returns the result of evaluating the given FHIRPath
     expression on that resource.  The advantage of this function over "evaluate"
     is that if you have multiple resources, the given FHIRPath expression will
     only be parsed once.
 
-    Parameters: 
+    Parameters:
     path (string) - the FHIRPath expression to be parsed.
     model (dict) - The "model" data object specific to a domain, e.g. R4.
 

fhirpathpy/engine/invocations/__init__.py

@@ -9,6 +9,7 @@
 import fhirpathpy.engine.invocations.misc as misc
 import fhirpathpy.engine.invocations.equality as equality
 import fhirpathpy.engine.invocations.logic as logic
+import fhirpathpy.engine.invocations.datetime as datetime
 
 invocations = {
     "empty": {"fn": existence.empty_fn},
@@ -68,9 +69,9 @@
     "round": {"fn": math.rround, "arity": {1: ["Number"]}},
     "sqrt": {"fn": math.sqrt},
     "truncate": {"fn": math.truncate},
-    # now:            {fn: datetime.now },
-    # today:          {fn: datetime.today },
-    #
+    "now": {"fn": datetime.now},
+    "today": {"fn": datetime.today},
+    "timeOfDay": {"fn": datetime.timeOfDay},
     "children": {"fn": navigation.children},
     "descendants": {"fn": navigation.descendants},
     "|": {"fn": combining.union_op, "arity": {2: ["Any", "Any"]}},

fhirpathpy/engine/invocations/constants.py

@@ -0,0 +1,25 @@
+import datetime
+
+
+class Constants:
+    """
+    These are values that should not change during an evaluation of a FHIRPath
+    expression (e.g. the return value of today(), per the spec.)  They are
+    constant during at least one evaluation.
+    """
+
+    nowDate = datetime.datetime.now()
+    today = None
+    now = None
+    timeOfDay = None
+    localTimezoneOffset = None
+
+    @classmethod
+    def reset(cls):
+        cls.nowDate = datetime.datetime.now()
+        cls.today = None
+        cls.now = None
+        cls.timeOfDay = None
+        cls.localTimezoneOffset = None
+
+constants = Constants()

fhirpathpy/engine/invocations/datetime.py

@@ -0,0 +1,28 @@
+from fhirpathpy.engine.invocations.constants import constants
+from fhirpathpy.engine.nodes import FP_DateTime, FP_Time, FP_Date
+
+
+def now(ctx, data):
+    if not constants.now:
+        now = constants.nowDate
+        if not now.tzinfo:
+            now = now.astimezone()
+        isoStr = now.replace(microsecond=0).isoformat()  # YYYY-MM-DDThh:mm:ss+zz:zz
+        constants.now = FP_DateTime(isoStr).timeMatchData
+    return constants.now
+
+
+def today(ctx, data):
+    if not constants.today:
+        now = constants.nowDate
+        isoStr = now.date().isoformat()  # YYYY-MM-DD
+        constants.today = FP_Date(isoStr).timeMatchData
+    return constants.today
+
+
+def timeOfDay(ctx, data):
+    if not constants.timeOfDay:
+        now = constants.nowDate
+        isoStr = now.time().replace(microsecond=0).isoformat()  # hh:mm:ss
+        constants.timeOfDay = FP_Time(isoStr).timeMatchData
+    return constants.timeOfDay

fhirpathpy/engine/nodes.py

@@ -1,4 +1,12 @@
 import json
+import re
+
+dateFormat = '([0-9]([0-9]([0-9][1-9]|[1-9]0)|[1-9]00)|[1-9]000)(-(0[1-9]|1[0-2])(-(0[1-9]|[1-2][0-9]|3[0-1])'
+dateRe = '%s)?)?' % dateFormat
+
+timeRE = '([01][0-9]|2[0-3]):[0-5][0-9]:([0-5][0-9]|60)(\.[0-9]+)?'
+
+dateTimeRE = '%s(T%s(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00)))?)?)?' % (dateFormat, timeRE)
 
 
 class FP_Type:
@@ -89,37 +97,79 @@ def toString(self):
 
 
 # TODO
-class FP_TimeBase:
-    pass
+class FP_TimeBase(FP_Type):
+
+    def __init__(self, timeStr):
+        self.asStr = timeStr
+        self.timeMatchData = None
+
+    def _getMatchData(self, regEx):
+        if not self.timeMatchData:
+            self.timeMatchData = re.match(regEx, self.asStr).group(0)
+        return self.timeMatchData
 
 
 # TODO
-class FP_Time:
+class FP_DateTime(FP_TimeBase):
+
+    def __init__(self, timeStr):
+        super(FP_DateTime, self).__init__(timeStr)
+        self.timeMatchData = self._getMatchData()
+
+    def _getMatchData(self, regEx=dateTimeRE):
+        return super(FP_DateTime, self)._getMatchData(regEx)
+
     @staticmethod
     def check_string(value):
         """
         Tests str to see if it is convertible to a DateTime.
         * @return If str is convertible to a DateTime, returns an FP_DateTime otherwise returns None
         """
-        d = FP_Time(value)
+        d = FP_DateTime(value)
         if not d._getMatchData():
             return None
         return d
 
 
 # TODO
-class FP_DateTime:
-    # TODO
-    def _getMatchData(self, data):
-        pass
+class FP_Date(FP_TimeBase):
+
+    def __init__(self, timeStr):
+        super(FP_Date, self).__init__(timeStr)
+        self.timeMatchData = self._getMatchData()
+
+    def _getMatchData(self, regEx=dateRe):
+        return super(FP_Date, self)._getMatchData(regEx)
 
     @staticmethod
     def check_string(value):
         """
         Tests str to see if it is convertible to a DateTime.
-        * @return If str is convertible to a DateTime, returns an FP_DateTime otherwise returns None
+        * @return If str is convertible to a DateTime, returns an FP_Date otherwise returns None
         """
-        d = FP_DateTime(value)
+        d = FP_Date(value)
+        if not d._getMatchData():
+            return None
+        return d
+
+
+# TODO
+class FP_Time(FP_TimeBase):
+
+    def __init__(self, timeStr):
+        super(FP_Time, self).__init__(timeStr)
+        self.timeMatchData = self._getMatchData()
+
+    def _getMatchData(self, regEx=timeRE):
+        return super(FP_Time, self)._getMatchData(regEx)
+
+    @staticmethod
+    def check_string(value):
+        """
+        Tests str to see if it is convertible to a DateTime.
+        * @return If str is convertible to a DateTime, returns an FP_Time otherwise returns None
+        """
+        d = FP_Time(value)
         if not d._getMatchData():
             return None
         return d

tests/cases/5.9_utility_functions.yaml

@@ -1,6 +1,7 @@
 tests:
   - desc: '5. Functions'
   - desc: '5.8. Utility functions'
+
   - desc: '5.8.1. trace(name : string) : collection'
 # Add a string representation of the input collection to the diagnostic log, using the parameter name as the name in the log. This log should be made available to the user in some appropriate fashion. Does not change the input, so returns the input collection as output.
 
@@ -9,21 +10,27 @@ tests:
     disableConsoleLog: true
     result: [1, 2, 3, 4, 5, 6]
 
-  - desc: '5.8.2. today() : dateTime'
+  - desc: '5.8.2. now() : dateTime'
+# Returns a dateTime containing the current date and time, including timezone.
+
+  - desc: '** TBD: now()'
+    expression: now()
+    result: ['2020-08-20T17:52:15+03:00']
+
+  - desc: '5.8.3. today() : dateTime'
 # Returns a dateTime containing the current date.
 
   - desc: '** TBD: today()'
-    # expression: Functions.today()
-    # result: '1234'
-
+    expression: today()
+    result: ['2020-08-20']
 
-  - desc: '5.8.3. now() : dateTime'
-# Returns a dateTime containing the current date and time, including timezone.
 
-  - desc: '** TBD: now()'
-    # expression: now()
-    # result: '10:10'
+  - desc: '5.8.4 timeOfDay() : dateTime'
+# Returns a dateTime containing the current time.
 
+  - desc: '** TBD: timeOfDay()'
+    expression: timeOfDay()
+    result: ['17:52:15']
 
 subject:
   coll:

tests/test_evaluators.py

@@ -1,7 +1,9 @@
+import datetime
 import math
 import pytest
 
 from fhirpathpy import evaluate
+from fhirpathpy.engine.invocations.constants import constants
 
 
 @pytest.mark.parametrize(
@@ -190,11 +192,15 @@ def existence_functions_test(resource, path, expected):
         ({"a": False}, "a.toDecimal()", [0]),
         ({"a": False}, "a.toString()", ["False"]),
         ({"a": 101.99}, "a.toString()", ["101.99"]),
-        # toDateTime
-        # toTime
+        ({}, "now()", ["2020-08-20T17:52:15+03:00"]),
+        ({}, "today()", ["2020-08-20"]),
+        ({}, "timeOfDay()", ["17:52:15"]),
     ],
 )
 def misc_functions_test(resource, path, expected):
+    # Monkeypatching for Constants.nowDate
+    tz = datetime.timezone(datetime.timedelta(seconds=10800))
+    constants.nowDate = datetime.datetime(year=2020, month=8, day=20, hour=17, minute=52, second=15, tzinfo=tz)
     assert evaluate(resource, path) == expected