refactor: better handling of tags in FilteredView

src/structurizr/view/filtered_view.py

@@ -14,9 +14,10 @@
 """Provide a filtered view."""
 
 from enum import Enum
-from typing import Iterable, List, Optional
+from typing import Iterable, List, Optional, Union
 
-from pydantic import Field
+from ordered_set import OrderedSet
+from pydantic import Field, validator
 
 from .abstract_view import AbstractView, AbstractViewIO
 from .static_view import StaticView
@@ -42,12 +43,22 @@ class FilteredViewIO(AbstractViewIO):
               upon the set of tag
         tags: The set of tags to include/exclude elements/relationships when rendering
               this filtered view.
+
+    Note that unlike Model Items, when filtered view tags are serialised to JSON then
+    they are serialised as an array rather than comma-separated.
     """
 
     base_view_key: str = Field(alias="baseViewKey")
     mode: FilterMode
     tags: List[str]
 
+    @validator("tags", pre=True)
+    def split_tags(cls, tags: Union[str, Iterable[str]]) -> List[str]:
+        """Convert comma-separated tag list into list if needed."""
+        if isinstance(tags, str):
+            return tags.split(",")
+        return list(tags)
+
 
 class FilteredView(AbstractView):
     """
@@ -78,7 +89,7 @@ def __init__(
         self._base_view_key = base_view_key
         self.view = view
         self.mode = mode
-        self.tags = set(tags)
+        self.tags = OrderedSet(tags)
 
     @property
     def base_view_key(self) -> str:

src/structurizr/view/view_set.py

@@ -152,7 +152,9 @@ def hydrate(cls, views: ViewSetIO, model: "Model") -> "ViewSet":
             cls._hydrate_view(view, model=model)
             dynamic_views.append(view)
 
-        filtered_views = [FilteredView.hydrate(view_io) for view_io in views.filtered_views]
+        filtered_views = [
+            FilteredView.hydrate(view_io) for view_io in views.filtered_views
+        ]
 
         result = cls(
             model=model,

tests/unit/view/test_filtered_view.py

@@ -47,3 +47,17 @@ def test_serialisation():
     assert view2.description == "test"
     assert view2.mode == FilterMode.Exclude
     assert view2.tags == {"v1"}
+
+
+def test_tags_are_serialised_as_an_array():
+    """Ensure that tags are serialised as an array, not comma-separated."""
+    container_view = ContainerView(key="static_key", description="container")
+    filtered_view = FilteredView(
+        key="filter1",
+        view=container_view,
+        description="test",
+        mode=FilterMode.Exclude,
+        tags=["v1", "test"],
+    )
+    io = FilteredViewIO.from_orm(filtered_view).json()
+    assert '"tags": ["v1", "test"]' in io