Anpassung an den Wrappern für sn_plan41

functions/ly_metadata_wrapper.py

@@ -1,35 +1,44 @@
-# layer/metadata.py
+# sn_basis/functions/ly_metadata_wrapper.py
 
-def get_layer_type(layer) -> str:
+from typing import Optional, List
+
+
+LAYER_TYPE_VECTOR = "vector"
+LAYER_TYPE_TABLE = "table"
+
+
+def get_layer_type(layer) -> Optional[str]:
+    """
+    Gibt den Layer-Typ zurück.
+
+    Rückgabewerte:
+    - "vector"
+    - "table"
+    - None (unbekannt / nicht bestimmbar)
+    """
     if layer is None:
-        return "unknown"
-
-    layer_type = getattr(layer, "layer_type", None)
-    if layer_type is not None:
-        return str(layer_type)
+        return None
 
     try:
-        if callable(getattr(layer, "isSpatial", None)):
-            return "vector" if layer.isSpatial() else "table"
+        is_spatial = getattr(layer, "isSpatial", None)
+        if callable(is_spatial):
+            return LAYER_TYPE_VECTOR if is_spatial() else LAYER_TYPE_TABLE
     except Exception:
         pass
 
-    return "unknown"
+    return None
 
 
-def get_layer_crs(layer) -> str:
+def get_layer_crs(layer) -> Optional[str]:
+    """
+    Gibt das CRS als AuthID zurück (z. B. 'EPSG:25833').
+    """
     if layer is None:
-        return "None"
-
-    crs = getattr(layer, "crs", None)
-    if crs is not None and not callable(crs):
-        if isinstance(crs, str):
-            return crs
-        return "None"
+        return None
 
     try:
-        crs_obj = layer.crs()
-        authid = getattr(crs_obj, "authid", None)
+        crs = layer.crs()
+        authid = getattr(crs, "authid", None)
         if callable(authid):
             value = authid()
             if isinstance(value, str):
@@ -37,49 +46,47 @@ def get_layer_crs(layer) -> str:
     except Exception:
         pass
 
-    return "None"
+    return None
 
 
-
-def get_layer_fields(layer) -> list[str]:
+def get_layer_fields(layer) -> List[str]:
+    """
+    Gibt die Feldnamen eines Layers zurück.
+    """
     if layer is None:
         return []
 
-    fields = getattr(layer, "fields", None)
-    if fields is not None and not callable(fields):
-        return list(fields)
-
     try:
-        f = layer.fields()
-        if callable(getattr(f, "names", None)):
-            return list(f.names())
-        return list(f)
+        return list(layer.fields().names())
     except Exception:
         return []
 
 
-def get_layer_source(layer) -> str:
-    if layer is None:
-        return "None"
 
-    source = getattr(layer, "source", None)
-    if source is not None and not callable(source):
-        return str(source)
+def get_layer_source(layer) -> Optional[str]:
+    """
+    Gibt die Datenquelle eines Layers zurück.
+    """
+    if layer is None:
+        return None
 
     try:
-        return layer.source() or "None"
+        value = layer.source()
+        if isinstance(value, str) and value:
+            return value
     except Exception:
-        return "None"
+        pass
+
+    return None
 
 
 def is_layer_editable(layer) -> bool:
+    """
+    Prüft, ob ein Layer editierbar ist.
+    """
     if layer is None:
         return False
 
-    editable = getattr(layer, "editable", None)
-    if editable is not None:
-        return bool(editable)
-
     try:
         is_editable = getattr(layer, "isEditable", None)
         if callable(is_editable):