Update to ifcopenshell.util.date for handling of IfcDuration with python and import of Planned Durations from P6 .xml exports in blenderBIM

src/ifcopenshell-python/ifcopenshell/util/date.py

@@ -1,6 +1,39 @@
 import datetime
 from re import findall
 
+# https://gist.github.com/spatialtime/c1924a3b178b4fe721fe406e0bf1a1dc
+import re
+from datetime import timedelta
+
+
+def format_duration(td):
+    s = td.seconds
+    ms = td.microseconds
+    if ms != 0:  # Round microseconds to milliseconds.
+        ms /= 1000000
+        ms = round(ms,3)
+        s += ms
+    return "P{}DT{}S".format(td.days,s)
+
+def parse_duration(iso_duration):
+    m = re.match(r'^P(?:(\d+)Y)?(?:(\d+)M)?(?:(\d+)D)?T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+(?:.\d+)?)S)?$',
+        iso_duration)
+    if m is None:
+        raise ValueError("invalid ISO 8601 duration string")
+    days = 0
+    hours = 0
+    minutes = 0
+    seconds = 0.0
+    if m[3]:
+        days = int(m[3])
+    if m[4]:
+        hours = int(m[4])
+    if m[5]:
+        minutes = int(m[5])
+    if m[6]:
+        seconds = float(m[6])
+    return timedelta(days=days, hours=hours, minutes=minutes, seconds=seconds)
+
 
 def duration2dict(duration):
     results = {}
@@ -11,7 +44,7 @@ def duration2dict(duration):
 
 def ifc2datetime(element):
     if isinstance(element, str) and element[0] == "P":  # IfcDuration
-        return duration2dict(element)
+        return parse_duration(element)
     elif isinstance(element, str) and element[2] == ":":  # IfcTime
         return datetime.time.fromisoformat(element)
     elif isinstance(element, str) and ":" in element:  # IfcDateTime
@@ -39,8 +72,10 @@ def ifc2datetime(element):
 
 
 def datetime2ifc(dt, ifc_type):
-    if isinstance(dt, str):
+    if isinstance(dt, str) and ifc_type != "IfcDuration":
         dt = datetime.datetime.fromisoformat(dt)
+    if ifc_type == "IfcDuration":
+        return format_duration(dt)
     if ifc_type == "IfcTimeStamp":
         return int(dt.timestamp())
     elif ifc_type == "IfcDateTime":