Add simple_text_subelement helper function

fastkml/features.py

@@ -30,6 +30,7 @@
 from fastkml.geometry import Point
 from fastkml.geometry import Polygon
 from fastkml.geometry import create_kml_geometry
+from fastkml.helpers import simple_text_subelement
 from fastkml.links import Link
 from fastkml.mixins import TimeMixin
 from fastkml.styles import Style
@@ -157,7 +158,7 @@ class _Feature(TimeMixin, _BaseObject):
     # A given KML Feature can contain a combination of these types of
     # custom data.
     #
-    # (2) is already implemented, see UntypedExtendedData
+    # (2 and 3) are already implemented, see data.py for more information.
     #
     # <Metadata> (deprecated in KML 2.2; use <ExtendedData> instead)
 
@@ -304,6 +305,7 @@ def etree_element(
             element.append(self._style_url.etree_element())
         for style in self.styles():
             element.append(style.etree_element())
+
         if self.snippet:
             snippet = config.etree.SubElement(  # type: ignore[attr-defined]
                 element,
@@ -312,18 +314,12 @@ def etree_element(
             snippet.text = self.snippet.text
             if self.snippet.max_lines:
                 snippet.set("maxLines", str(self.snippet.max_lines))
-        if self.name:
-            name = config.etree.SubElement(  # type: ignore[attr-defined]
-                element,
-                f"{self.ns}name",
-            )
-            name.text = self.name
-        if self.description:
-            description = config.etree.SubElement(  # type: ignore[attr-defined]
-                element,
-                f"{self.ns}description",
-            )
-            description.text = self.description
+
+        simple_text_subelement(self, element, "address", "address")
+        simple_text_subelement(self, element, "phone_number", "phoneNumber")
+        simple_text_subelement(self, element, "description", "description")
+        simple_text_subelement(self, element, "name", "name")
+
         if self.visibility is not None:
             visibility = config.etree.SubElement(  # type: ignore[attr-defined]
                 element,
@@ -336,18 +332,6 @@ def etree_element(
                 f"{self.ns}open",
             )
             isopen.text = str(int(self.isopen))
-        if self._address is not None:
-            address = config.etree.SubElement(  # type: ignore[attr-defined]
-                element,
-                f"{self.ns}address",
-            )
-            address.text = self._address
-        if self._phone_number is not None:
-            phone_number = config.etree.SubElement(  # type: ignore[attr-defined]
-                element,
-                f"{self.ns}phoneNumber",
-            )
-            phone_number.text = self._phone_number
         return element
 
     @classmethod
@@ -454,13 +438,25 @@ def _get_kwargs(
                 element=lookat,
                 strict=strict,
             )
+        snippet = element.find(f"{ns}Snippet")
+        if snippet is not None:
+            max_lines = snippet.get("maxLines")
+            if max_lines is not None:
+                kwargs["snippet"] = Snippet(text=snippet.text, max_lines=int(max_lines))
+            else:
+                kwargs["snippet"] = Snippet(  # type: ignore[unreachable]
+                    text=snippet.text,
+                )
         name = element.find(f"{ns}name")
         if name is not None:
             kwargs["name"] = name.text
         description = element.find(f"{ns}description")
         if description is not None:
             kwargs["description"] = description.text
         visibility = element.find(f"{ns}visibility")
+        phone_number = element.find(f"{ns}phoneNumber")
+        if phone_number is not None:
+            kwargs["phone_number"] = phone_number.text
         if visibility is not None and visibility.text:
             kwargs["visibility"] = visibility.text in {"1", "true"}
         isopen = element.find(f"{ns}open")
@@ -469,18 +465,6 @@ def _get_kwargs(
         address = element.find(f"{ns}address")
         if address is not None:
             kwargs["address"] = address.text
-        phone_number = element.find(f"{ns}phoneNumber")
-        if phone_number is not None:
-            kwargs["phone_number"] = phone_number.text
-        snippet = element.find(f"{ns}Snippet")
-        if snippet is not None:
-            max_lines = snippet.get("maxLines")
-            if max_lines is not None:
-                kwargs["snippet"] = Snippet(text=snippet.text, max_lines=int(max_lines))
-            else:
-                kwargs["snippet"] = Snippet(  # type: ignore[unreachable]
-                    text=snippet.text,
-                )
         return kwargs
 
 

fastkml/helpers.py

@@ -0,0 +1,20 @@
+"""Helper functions for fastkml."""
+
+from fastkml import config
+from fastkml.base import _BaseObject
+from fastkml.types import Element
+
+
+def simple_text_subelement(
+    obj: _BaseObject,
+    element: Element,
+    attr_name: str,
+    node_name: str,
+) -> None:
+    """Set the value of an attribute from a subelement with a text node."""
+    if getattr(obj, attr_name, None):
+        subelement = config.etree.SubElement(  # type: ignore[attr-defined]
+            element,
+            f"{obj.ns}{node_name}",
+        )
+        subelement.text = getattr(obj, attr_name)