Refine api style for change set

script/sql/api/1.title.sql

@@ -1,34 +1,68 @@
+drop function if exists update_title;
+drop function if exists get_title_update_template;
 drop function if exists get_title;
-
-create function get_title() returns text as
-$$
-select value from title as result;
-$$
-language sql;
+drop function if exists get_title_schema;
 
 
-drop function if exists set_title;
-
-create function set_title(new_value text) returns json as
+create function get_title_schema() returns jsonb as
 $$
 declare
-    old_value text;
+begin
+    return '{"value": {"opetional": false, "readonly": false}}'::jsonb;
+end;
+$$
+language plpgsql;
 
+
+create function get_title() returns jsonb as
+$$
+declare
+    v_value text;
+begin
+    select value into v_value from title;
+    return format('{"value": "%s"}', v_value)::jsonb;
+end;
+$$
+language plpgsql;
+
+
+create function get_title_update_template() returns jsonb as
+$$
+declare
+begin
+    return '{"operation": "update", "type": "title", "value": ""}'::jsonb;
+end;
+$$
+language plpgsql;
+
+
+create function update_title(new jsonb) returns jsonb as
+$$
+declare
+    old jsonb;
     redo_sql text;
     undo_sql text;
-    redo_cs json;
-    undo_cs json;
+    redo_cs jsonb;
+    undo_cs jsonb;
 
 begin
-    select value into old_value from title;
+    assert new->>'operation' = 'update';
+    assert new->>'type' = 'title';
+    assert new ? 'value';
 
-    redo_sql = format('update title set value = ''%s''', new_value);
-    undo_sql = format('update title set value = ''%s''', old_value);
-    redo_cs = format('{"operation": "update", "type": "title", "value": "%s" }', new_value)::json;
-    undo_cs = format('{"operation": "update", "type": "title", "value": "%s" }', old_value)::json;
-    execute add_operation(redo_sql, undo_sql, redo_cs, undo_cs);
+    old := get_title();
+    if old->>'value' = new->>'value' then
+        return '{}'::jsonb;
+    end if;
+
+    redo_sql := format('update title set value = ''%s''', new->>'value');
+    undo_sql := format('update title set value = ''%s''', old->>'value');
+
+    redo_cs := format('{"operation": "update", "type": "title", "value": "%s" }', new->>'value')::jsonb;
+    undo_cs := format('{"operation": "update", "type": "title", "value": "%s" }', old->>'value')::jsonb;
 
     execute redo_sql;
+    execute add_operation(redo_sql, undo_sql, redo_cs, undo_cs);
 
     return redo_cs;
 

script/sql/api/api.sql

@@ -0,0 +1,37 @@
+drop function if exists execute_command;
+drop function if exists execute_update;
+
+create function execute_update(cs jsonb) returns jsonb as
+$$
+declare
+begin
+    assert cs->>'operation' = 'update';
+
+    case cs->>'type'
+        when 'title' then
+            return update_title(cs);
+        else
+            return '{}'::jsonb;
+    end case;
+end;
+$$
+language plpgsql;
+
+
+create function execute_command(cs jsonb) returns jsonb as
+$$
+declare
+begin
+    case cs->>'operation'
+        when 'add' then
+            return '{}'::jsonb;
+        when 'update' then
+            return execute_update(cs);
+        when 'delete' then
+            return '{}'::jsonb;
+        else
+            return '{}'::jsonb;
+    end case;
+end;
+$$
+language plpgsql;

script/sql/api/operation.sql

@@ -1,5 +1,8 @@
+drop function if exists execute_undo;
+drop function if exists add_operation;
 drop function if exists get_current_operation;
 
+
 create function get_current_operation() returns integer as
 $$
 select id from current_operation as result;
@@ -7,9 +10,7 @@ $$
 language sql;
 
 
-drop function if exists add_operation;
-
-create function add_operation(redo_sql text, undo_sql text, redo_cs json, undo_cs json) returns void as
+create function add_operation(redo_sql text, undo_sql text, redo_cs jsonb, undo_cs jsonb) returns void as
 $$
 declare
     parent_id integer;
@@ -30,9 +31,7 @@ $$
 language plpgsql;
 
 
-drop function if exists execute_undo;
-
-create function execute_undo(discard boolean) returns json as
+create function execute_undo(discard boolean) returns jsonb as
 $$
 #print_strict_params on
 
@@ -42,7 +41,7 @@ declare
 begin
     select * into strict op_row from operation where id = get_current_operation();
     if op_row.undo = '' then
-        return '{}'::json;
+        return '{}'::jsonb;
     end if;
 
     execute op_row.undo;
@@ -66,7 +65,7 @@ $$
 language plpgsql;
 
 
--- create function execute_redo() returns json as
+-- create function execute_redo() returns jsonb as
 -- $$
 -- #print_strict_params on
 -- 

script/sql/create/operation.sql

@@ -5,8 +5,8 @@ create table operation
 , undo text not null
 , parent integer references operation(id) on delete cascade
 , redo_child integer references operation(id) -- must update before delete
-, redo_change_set json
-, undo_change_set json
+, redo_change_set jsonb
+, undo_change_set jsonb
 );
 
 insert into operation (id, redo, undo) values (0, '', '');

script/template.py

@@ -30,12 +30,13 @@ sql_create = [
     "sql/create/26.labels.sql",
     "sql/create/27.backdrop.sql",
     "sql/create/28.end.sql",
-    "sql/create/operation.sql",
+    "sql/create/operation.sql"
 ]
 
 sql_api = [
     "sql/api/operation.sql",
-    "sql/api/1.title.sql"
+    "sql/api/1.title.sql",
+    "sql/api/api.sql"
 ]
 
 sql_drop = [