feat: Add support for python lambda filter

capellambse_context_diagrams/collectors/custom.py

@@ -116,9 +116,41 @@ def _fix_box_heights(self) -> None:
                 box = self.boxes[uuid]
                 box.height = max([box.height] + list(min_heights.values()))
 
+    def _safely_eval_filter(self, obj: m.ModelElement, filter: str) -> bool:
+        if not filter.startswith("lambda"):
+            raise ValueError(f"Filter '{filter}' is not a lambda expression.")
+
+        import capellambse
+
+        allowed_builtins = {
+            "True": True,
+            "False": False,
+            "isinstance": isinstance,
+            "len": len,
+            "sum": sum,
+            "min": min,
+            "max": max,
+            "abs": abs,
+            "round": round,
+            "capellambse": capellambse,
+        }
+        try:
+            result = eval(filter, {"__builtins__": allowed_builtins})(obj)
+        except Exception as e:
+            raise ValueError(
+                f"Filter '{filter}' raised an exception: {e}"
+            ) from e
+        if not isinstance(result, bool):
+            raise ValueError(
+                f"Filter '{filter}' did not return a boolean value."
+            )
+        return result
+
     def _matches_filters(
-        self, obj: m.ModelElement, filters: dict[str, t.Any]
+        self, obj: m.ModelElement, filters: dict[str, t.Any] | str
     ) -> bool:
+        if isinstance(filters, str):
+            return self._safely_eval_filter(obj, filters)
         for key, value in filters.items():
             if getattr(obj, key) != value:
                 return False