Add topic tags to search

Previously, search only covered topic titles and markdown. This adds
tags to it as well, and will make it easier to add other things in the
future since there's now a custom function instead of using the built-in
one that only supports text columns.

tildes/alembic/versions/5a7dc1032efc_add_tags_to_topic_search_vector.py

@@ -0,0 +1,105 @@
+"""Add tags to topic search vector
+
+Revision ID: 5a7dc1032efc
+Revises: 22a8ed36a3c9
+Create Date: 2018-10-16 02:09:33.528836
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "5a7dc1032efc"
+down_revision = "22a8ed36a3c9"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.execute("DROP TRIGGER topic_update_search_tsv_insert ON topics")
+    op.execute("DROP TRIGGER topic_update_search_tsv_update ON topics")
+
+    op.execute(
+        """
+        CREATE OR REPLACE FUNCTION update_topic_search_tsv() RETURNS TRIGGER AS $$
+        BEGIN
+            NEW.search_tsv :=
+                to_tsvector(NEW.title) ||
+                to_tsvector(coalesce(NEW.markdown, '')) ||
+                -- convert tags to space-separated string and replace periods with spaces
+                to_tsvector(replace(array_to_string(NEW.tags, ' '), '.', ' '));
+
+            RETURN NEW;
+        END;
+        $$ LANGUAGE plpgsql;
+    """
+    )
+
+    op.execute(
+        """
+        CREATE TRIGGER topic_update_search_tsv_insert
+            BEFORE INSERT ON topics
+            FOR EACH ROW
+            EXECUTE PROCEDURE update_topic_search_tsv();
+    """
+    )
+
+    op.execute(
+        """
+        CREATE TRIGGER topic_update_search_tsv_update
+            BEFORE UPDATE ON topics
+            FOR EACH ROW
+            WHEN (
+                (OLD.title IS DISTINCT FROM NEW.title)
+                OR (OLD.markdown IS DISTINCT FROM NEW.markdown)
+                OR (OLD.tags IS DISTINCT FROM NEW.tags)
+            )
+            EXECUTE PROCEDURE update_topic_search_tsv();
+    """
+    )
+
+    op.execute(
+        """
+        UPDATE topics SET search_tsv =
+            to_tsvector(title) ||
+            to_tsvector(coalesce(markdown, '')) ||
+            to_tsvector(replace(array_to_string(tags, ' '), '.', ' '));
+    """
+    )
+
+
+def downgrade():
+    op.execute("DROP TRIGGER topic_update_search_tsv_update ON topics")
+    op.execute("DROP TRIGGER topic_update_search_tsv_insert ON topics")
+    op.execute("DROP FUNCTION update_topic_search_tsv()")
+
+    op.execute(
+        """
+        CREATE TRIGGER topic_update_search_tsv_insert
+            BEFORE INSERT ON topics
+            FOR EACH ROW
+            EXECUTE PROCEDURE tsvector_update_trigger(search_tsv, 'pg_catalog.english', title, markdown);
+    """
+    )
+
+    op.execute(
+        """
+        CREATE TRIGGER topic_update_search_tsv_update
+            BEFORE UPDATE ON topics
+            FOR EACH ROW
+            WHEN (
+                (OLD.title IS DISTINCT FROM NEW.title)
+                OR (OLD.markdown IS DISTINCT FROM NEW.markdown)
+            )
+            EXECUTE PROCEDURE tsvector_update_trigger(search_tsv, 'pg_catalog.english', title, markdown);
+    """
+    )
+
+    op.execute(
+        """
+        UPDATE topics SET search_tsv =
+            to_tsvector(title) ||
+            to_tsvector(coalesce(markdown, ''));
+    """
+    )

tildes/sql/init/triggers/topics/topics.sql

@@ -17,10 +17,23 @@ CREATE TRIGGER delete_topic_set_deleted_time_update
     EXECUTE PROCEDURE set_topic_deleted_time();
 
 
+CREATE OR REPLACE FUNCTION update_topic_search_tsv() RETURNS TRIGGER AS $$
+BEGIN
+    NEW.search_tsv :=
+        to_tsvector(NEW.title) ||
+        to_tsvector(coalesce(NEW.markdown, '')) ||
+        -- convert tags to space-separated string and replace periods with spaces
+        to_tsvector(replace(array_to_string(NEW.tags, ' '), '.', ' '));
+
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+
 CREATE TRIGGER topic_update_search_tsv_insert
     BEFORE INSERT ON topics
     FOR EACH ROW
-    EXECUTE PROCEDURE tsvector_update_trigger(search_tsv, 'pg_catalog.english', title, markdown);
+    EXECUTE PROCEDURE update_topic_search_tsv();
 
 CREATE TRIGGER topic_update_search_tsv_update
     BEFORE UPDATE ON topics
@@ -28,5 +41,6 @@ CREATE TRIGGER topic_update_search_tsv_update
     WHEN (
         (OLD.title IS DISTINCT FROM NEW.title)
         OR (OLD.markdown IS DISTINCT FROM NEW.markdown)
+        OR (OLD.tags IS DISTINCT FROM NEW.tags)
     )
-    EXECUTE PROCEDURE tsvector_update_trigger(search_tsv, 'pg_catalog.english', title, markdown);
+    EXECUTE PROCEDURE update_topic_search_tsv();