Migrate callers from attach-child/detach-child to relate/unrelate API

Switch all cross-service relation calls to the new registry-aware
relate/unrelate/can-relate actions, and consolidate per-service
container-nav fragment fetches into the generic relations handler.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blog/bp/blog/routes.py

@@ -103,7 +103,7 @@ def register(url_prefix, title):
       from shared.infrastructure.cart_identity import current_cart_identity
       from shared.infrastructure.data_client import fetch_data
       from shared.contracts.dtos import CartSummaryDTO, dto_from_dict
-      from shared.infrastructure.fragments import fetch_fragment, fetch_fragments
+      from shared.infrastructure.fragments import fetch_fragment
 
       p_data = await _post_data("home", g.s, include_drafts=False)
       if not p_data:
@@ -116,22 +116,12 @@ def register(url_prefix, title):
       db_post_id = p_data["post"]["id"]
       post_slug = p_data["post"]["slug"]
 
-      # Fetch container nav fragments from events + market
-      paginate_url = url_for(
-          'blog.post.widget_paginate',
-          slug=post_slug, widget_domain='calendar',
-      )
-      nav_params = {
+      # Fetch container nav from relations service
+      container_nav_html = await fetch_fragment("relations", "container-nav", params={
           "container_type": "page",
           "container_id": str(db_post_id),
           "post_slug": post_slug,
-          "paginate_url": paginate_url,
-      }
-      events_nav_html, market_nav_html = await fetch_fragments([
-          ("events", "container-nav", nav_params),
-          ("market", "container-nav", nav_params),
-      ])
-      container_nav_html = events_nav_html + market_nav_html
+      })
 
       ctx = {
           **p_data,

blog/bp/menu_items/services/menu_items.py

@@ -80,9 +80,11 @@ async def create_menu_item(
     )
     session.add(menu_node)
     await session.flush()
-    await call_action("relations", "attach-child", payload={
-        "parent_type": "page", "parent_id": post_id,
-        "child_type": "menu_node", "child_id": menu_node.id,
+    await call_action("relations", "relate", payload={
+        "relation_type": "page->menu_node",
+        "from_id": post_id, "to_id": menu_node.id,
+        "label": post.title,
+        "metadata": {"slug": post.slug},
     })
 
     return menu_node
@@ -134,13 +136,15 @@ async def update_menu_item(
     await session.flush()
 
     if post_id is not None and post_id != old_post_id:
-        await call_action("relations", "detach-child", payload={
-            "parent_type": "page", "parent_id": old_post_id,
-            "child_type": "menu_node", "child_id": menu_node.id,
+        await call_action("relations", "unrelate", payload={
+            "relation_type": "page->menu_node",
+            "from_id": old_post_id, "to_id": menu_node.id,
         })
-        await call_action("relations", "attach-child", payload={
-            "parent_type": "page", "parent_id": post_id,
-            "child_type": "menu_node", "child_id": menu_node.id,
+        await call_action("relations", "relate", payload={
+            "relation_type": "page->menu_node",
+            "from_id": post_id, "to_id": menu_node.id,
+            "label": post.title,
+            "metadata": {"slug": post.slug},
         })
 
     return menu_node
@@ -154,9 +158,9 @@ async def delete_menu_item(session: AsyncSession, item_id: int) -> bool:
 
     menu_node.deleted_at = func.now()
     await session.flush()
-    await call_action("relations", "detach-child", payload={
-        "parent_type": "page", "parent_id": menu_node.container_id,
-        "child_type": "menu_node", "child_id": menu_node.id,
+    await call_action("relations", "unrelate", payload={
+        "relation_type": "page->menu_node",
+        "from_id": menu_node.container_id, "to_id": menu_node.id,
     })
 
     return True

blog/bp/post/routes.py

@@ -13,7 +13,7 @@ from .services.post_data import post_data
 from shared.infrastructure.data_client import fetch_data
 from shared.infrastructure.actions import call_action
 from shared.contracts.dtos import CartSummaryDTO, dto_from_dict
-from shared.infrastructure.fragments import fetch_fragment, fetch_fragments
+from shared.infrastructure.fragments import fetch_fragment
 
 from shared.browser.app.redis_cacher import cache_page, clear_cache
 
@@ -69,22 +69,12 @@ def register():
           db_post_id = (g.post_data.get("post") or {}).get("id")
           post_slug = (g.post_data.get("post") or {}).get("slug", "")
 
-          # Fetch container nav fragments from events + market
-          paginate_url = url_for(
-              'blog.post.widget_paginate',
-              slug=post_slug, widget_domain='calendar',
-          )
-          nav_params = {
+          # Fetch container nav from relations service
+          container_nav_html = await fetch_fragment("relations", "container-nav", params={
               "container_type": "page",
               "container_id": str(db_post_id),
               "post_slug": post_slug,
-              "paginate_url": paginate_url,
-          }
-          events_nav_html, market_nav_html = await fetch_fragments([
-              ("events", "container-nav", nav_params),
-              ("market", "container-nav", nav_params),
-          ])
-          container_nav_html = events_nav_html + market_nav_html
+          })
 
           ctx = {
               **p_data,

blog/bp/post/services/markets.py

@@ -7,7 +7,6 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from shared.contracts.dtos import MarketPlaceDTO
 from shared.infrastructure.actions import call_action, ActionError
-from shared.infrastructure.data_client import fetch_data
 from shared.services.registry import services
 
 
@@ -41,11 +40,11 @@ async def create_market(sess: AsyncSession, post_id: int, name: str) -> MarketPl
     if not post.is_page:
         raise MarketError("Markets can only be created on pages, not posts.")
 
-    raw_pc = await fetch_data("blog", "page-config",
-        params={"container_type": "page", "container_id": post_id},
-        required=False)
-    if raw_pc is None or not (raw_pc.get("features") or {}).get("market"):
-        raise MarketError("Market feature is not enabled for this page. Enable it in page settings first.")
+    check = await call_action("relations", "can-relate", payload={
+        "relation_type": "page->market", "from_id": post_id,
+    })
+    if not check.get("allowed"):
+        raise MarketError(check.get("reason", "Cannot create market for this page."))
 
     try:
         result = await call_action("market", "create-marketplace", payload={

events/bp/calendar_entry/routes.py

@@ -215,16 +215,17 @@ def register():
                             ticket_type_id=tt.id,
                         )
 
-        # Fetch container nav from market (skip calendar — we're on a calendar page)
+        # Fetch container nav from relations (exclude calendar — we're on a calendar page)
         container_nav_html = ""
         post_data = getattr(g, "post_data", None)
         if post_data:
             post_id = post_data["post"]["id"]
             post_slug = post_data["post"]["slug"]
-            container_nav_html = await fetch_fragment("market", "container-nav", params={
+            container_nav_html = await fetch_fragment("relations", "container-nav", params={
                 "container_type": "page",
                 "container_id": str(post_id),
                 "post_slug": post_slug,
+                "exclude": "page->calendar",
             })
 
         return {

events/bp/calendars/services/calendars.py

@@ -71,9 +71,9 @@ async def soft_delete(sess: AsyncSession, post_slug: str, calendar_slug: str) ->
 
     cal.deleted_at = utcnow()
     await sess.flush()
-    await call_action("relations", "detach-child", payload={
-        "parent_type": "page", "parent_id": cal.container_id,
-        "child_type": "calendar", "child_id": cal.id,
+    await call_action("relations", "unrelate", payload={
+        "relation_type": "page->calendar",
+        "from_id": cal.container_id, "to_id": cal.id,
     })
     return True
 
@@ -108,9 +108,11 @@ async def create_calendar(sess: AsyncSession, post_id: int, name: str) -> Calend
         if existing.deleted_at is not None:
             existing.deleted_at = None  # revive
             await sess.flush()
-            await call_action("relations", "attach-child", payload={
-                "parent_type": "page", "parent_id": post_id,
-                "child_type": "calendar", "child_id": existing.id,
+            await call_action("relations", "relate", payload={
+                "relation_type": "page->calendar",
+                "from_id": post_id, "to_id": existing.id,
+                "label": existing.name,
+                "metadata": {"slug": existing.slug},
             })
             return existing
         raise CalendarError(f'Calendar with slug "{slug}" already exists for post {post_id}.')
@@ -118,9 +120,11 @@ async def create_calendar(sess: AsyncSession, post_id: int, name: str) -> Calend
     cal = Calendar(container_type="page", container_id=post_id, name=name, slug=slug)
     sess.add(cal)
     await sess.flush()
-    await call_action("relations", "attach-child", payload={
-        "parent_type": "page", "parent_id": post_id,
-        "child_type": "calendar", "child_id": cal.id,
+    await call_action("relations", "relate", payload={
+        "relation_type": "page->calendar",
+        "from_id": post_id, "to_id": cal.id,
+        "label": cal.name,
+        "metadata": {"slug": cal.slug},
     })
     return cal
 

events/bp/day/routes.py

@@ -78,16 +78,17 @@ def register():
         result = await g.s.execute(stmt)
         day_slots = list(result.scalars())
 
-        # Fetch container nav from market (skip calendar — we're on a calendar page)
+        # Fetch container nav from relations (exclude calendar — we're on a calendar page)
         container_nav_html = ""
         post_data = getattr(g, "post_data", None)
         if post_data:
             post_id = post_data["post"]["id"]
             post_slug = post_data["post"]["slug"]
-            container_nav_html = await fetch_fragment("market", "container-nav", params={
+            container_nav_html = await fetch_fragment("relations", "container-nav", params={
                 "container_type": "page",
                 "container_id": str(post_id),
                 "post_slug": post_slug,
+                "exclude": "page->calendar",
             })
 
         return {
@@ -141,10 +142,11 @@ def register():
         post_slug = post_data["post"]["slug"]
 
         if widget_domain == "market":
-            html = await fetch_fragment("market", "container-nav", params={
+            html = await fetch_fragment("relations", "container-nav", params={
                 "container_type": "page",
                 "container_id": str(post_id),
                 "post_slug": post_slug,
+                "exclude": "page->calendar",
             })
             return await make_response(html or "")
         abort(404)

relations/bp/fragments/routes.py

@@ -47,6 +47,7 @@ def register():
         container_type = request.args.get("container_type", "page")
         container_id = int(request.args.get("container_id", 0))
         post_slug = request.args.get("post_slug", "")
+        nav_class = request.args.get("nav_class", "")
         exclude_raw = request.args.get("exclude", "")
         exclude = set(exclude_raw.split(",")) if exclude_raw else set()
 
@@ -76,7 +77,7 @@ def register():
                     name=child.label or "",
                     icon=defn.nav_icon or "",
                     **{
-                        "nav-class": "",
+                        "nav-class": nav_class,
                         "relation-type": defn.name,
                     },
                 ))

shared/services/market_impl.py

@@ -93,9 +93,11 @@ class SqlMarketService:
                 existing.deleted_at = None  # revive
                 existing.name = name
                 await session.flush()
-                await call_action("relations", "attach-child", payload={
-                    "parent_type": container_type, "parent_id": container_id,
-                    "child_type": "market", "child_id": existing.id,
+                await call_action("relations", "relate", payload={
+                    "relation_type": f"{container_type}->market",
+                    "from_id": container_id, "to_id": existing.id,
+                    "label": existing.name,
+                    "metadata": {"slug": existing.slug},
                 })
                 return _mp_to_dto(existing)
             raise ValueError(f'Market with slug "{slug}" already exists for this container.')
@@ -106,9 +108,11 @@ class SqlMarketService:
         )
         session.add(market)
         await session.flush()
-        await call_action("relations", "attach-child", payload={
-            "parent_type": container_type, "parent_id": container_id,
-            "child_type": "market", "child_id": market.id,
+        await call_action("relations", "relate", payload={
+            "relation_type": f"{container_type}->market",
+            "from_id": container_id, "to_id": market.id,
+            "label": market.name,
+            "metadata": {"slug": market.slug},
         })
         return _mp_to_dto(market)
 
@@ -130,8 +134,8 @@ class SqlMarketService:
 
         market.deleted_at = utcnow()
         await session.flush()
-        await call_action("relations", "detach-child", payload={
-            "parent_type": container_type, "parent_id": container_id,
-            "child_type": "market", "child_id": market.id,
+        await call_action("relations", "unrelate", payload={
+            "relation_type": f"{container_type}->market",
+            "from_id": container_id, "to_id": market.id,
         })
         return True