feat: register collections via collection:register_collections signal

ckanext/collection/plugin.py

@@ -54,6 +54,11 @@ class ApImplementation(p.SingletonPlugin):
         pass
 
 
+register_collection_signal = tk.signals.ckanext.signal(
+    "collection:register_collections",
+)
+
+
 @tk.blanket.blueprints
 @tk.blanket.auth_functions
 @tk.blanket.config_declarations
@@ -62,6 +67,7 @@ class ApImplementation(p.SingletonPlugin):
 class CollectionPlugin(ApImplementation, p.SingletonPlugin):
     p.implements(p.IConfigurer)
     p.implements(p.IConfigurable)
+    # p.implements(p.ISignal)
     p.implements(ICollection, inherit=True)
 
     # IConfigurer
@@ -79,6 +85,10 @@ def configure(self, config_: CKANConfig):
             for name, factory in plugin.get_collection_factories().items():
                 shared.collection_registry.register(name, factory)
 
+        for _, factories in register_collection_signal.send():
+            for name, factory in factories.items():
+                shared.collection_registry.register(name, factory)
+
     def get_collection_factories(self) -> dict[str, CollectionFactory]:
         if tk.config["debug"]:
             from .utils import (