IDOM_DATABASE param

reactive-python · Archmonger · Feb 21, 2023 · Feb 4, 2023 · Feb 21, 2023 · Feb 21, 2023
commit 3877e8d2f582e8283b942ac0b1b6f7a0bf1b03b3
@@ -70,7 +70,7 @@ Using the following categories, list your changes in this order:
 
 ### Fixed
 
--   `view_to_component` will now retain any HTML that was defined in a `<head>` tag.
+-   `view_to_component` will now retain the contents of a `<head>` tag when rendering.
 -   React client is now set to `production` rather than `development`.
 -   `use_query` will now utilize `field.related_name` when postprocessing many-to-one relationships
 

@@ -4,6 +4,9 @@
     "idom": {"BACKEND": ...},
 }
 
+# IDOM works best with a multiprocessing-safe and thread-safe database backend.
+IDOM_DATABASE = "default"
+
 # Maximum seconds between reconnection attempts before giving up.
 # Use `0` to prevent component reconnection.
 IDOM_RECONNECT_MAX = 259200

@@ -4,6 +4,7 @@
 
 from django.conf import settings
 from django.core.cache import DEFAULT_CACHE_ALIAS, BaseCache, caches
+from django.db import DEFAULT_DB_ALIAS
 from idom.config import IDOM_DEBUG_MODE
 from idom.core.types import ComponentConstructor
 
@@ -29,6 +30,11 @@
     if "idom" in getattr(settings, "CACHES", {})
     else caches[DEFAULT_CACHE_ALIAS]
 )
+IDOM_DATABASE: str = getattr(
+    settings,
+    "IDOM_DATABASE",
+    DEFAULT_DB_ALIAS,
+)
 IDOM_DEFAULT_QUERY_POSTPROCESSOR: Postprocessor | None = import_dotted_path(
     getattr(
         settings,

@@ -2,6 +2,10 @@
 
 
 class ComponentParams(models.Model):
+    """A model for storing component parameters.
+    All queries must be routed through `django_idom.config.IDOM_DATABASE`.
+    """
+
     uuid = models.UUIDField(primary_key=True, editable=False, unique=True)  # type: ignore
     data = models.BinaryField(editable=False)  # type: ignore
     last_accessed = models.DateTimeField(auto_now_add=True)  # type: ignore
@@ -311,7 +311,7 @@ def create_cache_key(*args):
 def db_cleanup(immediate: bool = False):
     """Deletes expired component parameters from the database.
     This function may be expanded in the future to include additional cleanup tasks."""
-    from .config import IDOM_CACHE, IDOM_RECONNECT_MAX
+    from .config import IDOM_CACHE, IDOM_DATABASE, IDOM_RECONNECT_MAX
     from .models import ComponentParams
 
     cache_key: str = create_cache_key("last_cleaned")
@@ -324,7 +324,7 @@ def db_cleanup(immediate: bool = False):
     expires_by: datetime = timezone.now() - timedelta(seconds=IDOM_RECONNECT_MAX)
 
     # Component params exist in the DB, but we don't know when they were last cleaned
-    if not cleaned_at_str and ComponentParams.objects.all():
+    if not cleaned_at_str and ComponentParams.objects.using(IDOM_DATABASE).all():
         _logger.warning(
             "IDOM has detected component sessions in the database, "
             "but no timestamp was found in cache. This may indicate that "
@@ -334,5 +334,7 @@ def db_cleanup(immediate: bool = False):
     # Delete expired component parameters
     # Use timestamps in cache (`cleaned_at_str`) as a no-dependency rate limiter
     if immediate or not cleaned_at_str or timezone.now() >= clean_needed_by:
-        ComponentParams.objects.filter(last_accessed__lte=expires_by).delete()
+        ComponentParams.objects.using(IDOM_DATABASE).filter(
+            last_accessed__lte=expires_by
+        ).delete()
         IDOM_CACHE.set(cache_key, now_str)
@@ -55,7 +55,11 @@ async def receive_json(self, content: Any, **_) -> None:
 
     async def _run_dispatch_loop(self):
         from django_idom import models
-        from django_idom.config import IDOM_RECONNECT_MAX, IDOM_REGISTERED_COMPONENTS
+        from django_idom.config import (
+            IDOM_DATABASE,
+            IDOM_RECONNECT_MAX,
+            IDOM_REGISTERED_COMPONENTS,
+        )
 
         scope = self.scope
         dotted_path = scope["url_route"]["kwargs"]["dotted_path"]
@@ -91,7 +95,9 @@ async def _run_dispatch_loop(self):
                     await convert_to_async(db_cleanup)()
 
                     # Get the queries from a DB
-                    params_query = await models.ComponentParams.objects.aget(
+                    params_query = await models.ComponentParams.objects.using(
+                        IDOM_DATABASE
+                    ).aget(
                         uuid=uuid,
                         last_accessed__gt=now - timedelta(seconds=IDOM_RECONNECT_MAX),
                     )