structured-liquibase-files (#29)

Co-authored-by: Michael Hoennig <michael@hoennig.de>
Reviewed-on: https://dev.hostsharing.net/hostsharing/hs.hsadmin.ng/pulls/29
Reviewed-by: Timotheus Pokorra <timotheus.pokorra@hostsharing.net>

src/main/resources/db/changelog/1-rbac/1056-rbac-trigger-context.sql

@@ -0,0 +1,61 @@
+--liquibase formatted sql
+
+
+-- ============================================================================
+--changeset rbac-trigger-context-ENTER:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+
+create or replace procedure enterTriggerForObjectUuid(currentObjectUuid uuid)
+    language plpgsql as $$
+declare
+    existingObjectUuid text;
+begin
+    existingObjectUuid = current_setting('hsadminng.currentObjectUuid', true);
+    if (existingObjectUuid > '' ) then
+        raise exception '[500] currentObjectUuid already defined, already in trigger of "%"', existingObjectUuid;
+    end if;
+    execute format('set local hsadminng.currentObjectUuid to %L', currentObjectUuid);
+end; $$;
+
+
+-- ============================================================================
+--changeset rbac-trigger-context-CURRENT-ID:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+/*
+    Returns the uuid of the object uuid whose trigger is currently executed as set via `enterTriggerForObjectUuid(...)`.
+ */
+
+create or replace function currentTriggerObjectUuid()
+    returns uuid
+    stable -- leakproof
+    language plpgsql as $$
+declare
+    currentObjectUuid uuid;
+begin
+    begin
+        currentObjectUuid = current_setting('hsadminng.currentObjectUuid')::uuid;
+        return currentObjectUuid;
+    exception
+        when others then
+            return null::uuid;
+    end;
+end; $$;
+--//
+
+
+-- ============================================================================
+--changeset rbac-trigger-context-LEAVE:1 endDelimiter:--//
+-- ----------------------------------------------------------------------------
+
+create or replace procedure leaveTriggerForObjectUuid(currentObjectUuid uuid)
+    language plpgsql as $$
+declare
+    existingObjectUuid uuid;
+begin
+    existingObjectUuid = current_setting('hsadminng.currentObjectUuid', true);
+    if ( existingObjectUuid <> currentObjectUuid ) then
+        raise exception '[500] currentObjectUuid does not match: "%"', existingObjectUuid;
+    end if;
+    execute format('reset hsadminng.currentObjectUuid');
+end; $$;
+