first base of project-changed apps: Herd-livestock-tag-log-elasticsearch-

apps/search/signals.py

@@ -0,0 +1,71 @@
+from django.db.models.signals import post_save, post_delete
+from django.dispatch import receiver
+
+from django_elasticsearch_dsl.registries import registry
+
+
+@receiver(post_save)
+def update_document(sender, **kwargs):
+    """Update document on added/changed records.
+
+    Update Book document index if related `books.Publisher` (`publisher`),
+    `books.Author` (`authors`), `books.Tag` (`tags`) fields have been updated
+    in the database.
+    """
+    app_label = sender._meta.app_label
+    model_name = sender._meta.model_name
+    instance = kwargs['instance']
+
+    if app_label == 'book':
+        # If it is `books.Publisher` that is being updated.
+        if model_name == 'publisher':
+            instances = instance.books.all()
+            for _instance in instances:
+                registry.update(_instance)
+
+        # If it is `books.Author` that is being updated.
+        if model_name == 'author':
+            instances = instance.books.all()
+            for _instance in instances:
+                registry.update(_instance)
+
+        # If it is `books.Tag` that is being updated.
+        if model_name == 'tag':
+            instances = instance.books.all()
+            for _instance in instances:
+                registry.update(_instance)
+
+
+@receiver(post_delete)
+def delete_document(sender, **kwargs):
+    """Update document on deleted records.
+
+    Updates Book document from index if related `books.Publisher`
+    (`publisher`), `books.Author` (`authors`), `books.Tag` (`tags`) fields
+    have been removed from database.
+    """
+    app_label = sender._meta.app_label
+    model_name = sender._meta.model_name
+    instance = kwargs['instance']
+
+    if app_label == 'books':
+        # If it is `books.Publisher` that is being updated.
+        if model_name == 'publisher':
+            instances = instance.books.all()
+            for _instance in instances:
+                registry.update(_instance)
+                # registry.delete(_instance, raise_on_error=False)
+
+        # If it is `books.Author` that is being updated.
+        if model_name == 'author':
+            instances = instance.books.all()
+            for _instance in instances:
+                registry.update(_instance)
+                # registry.delete(_instance, raise_on_error=False)
+
+        # If it is `books.Tag` that is being updated.
+        if model_name == 'tag':
+            instances = instance.books.all()
+            for _instance in instances:
+                registry.update(_instance)
+                # registry.delete(_instance, raise_on_error=False)