Class: PgAuditLog::Function

Inherits:
ActiveRecord show all
Defined in:
lib/pg_audit_log/function.rb

Constant Summary collapse

DISABLED_USER = 
-2396

Class Method Summary collapse

Class Method Details

.install ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 46

def install
  execute <<-SQL
  CREATE OR REPLACE PROCEDURAL LANGUAGE plpgsql;
  CREATE OR REPLACE FUNCTION #{name}() RETURNS trigger
  LANGUAGE plpgsql
  AS $_$
      DECLARE
        col information_schema.columns %ROWTYPE;
        new_value text;
        old_value text;
        primary_key_column varchar;
        primary_key_value varchar;
        user_identifier integer;
        unique_name varchar;
        column_name varchar;
      BEGIN
        user_identifier := #{pg_audit_log_old_style_user_id ? %q(current_setting('audit.user_id')) : 'pg_temp.pg_audit_log_user_identifier()'};
        IF user_identifier = #{DISABLED_USER} THEN
          RETURN NULL;
        END IF;
        unique_name := #{pg_audit_log_old_style_user_id ? %q(current_setting('audit.user_unique_name')) : 'pg_temp.pg_audit_log_user_unique_name()'};
        primary_key_column := NULL;
        EXECUTE 'SELECT pg_attribute.attname
                 FROM pg_index, pg_class, pg_attribute
                 WHERE pg_class.oid = $1::regclass
                 AND indrelid = pg_class.oid
                 AND pg_attribute.attrelid = pg_class.oid
                 AND pg_attribute.attnum = any(pg_index.indkey)
                 AND indisprimary'
        INTO primary_key_column USING TG_RELNAME;
        primary_key_value := NULL;

        FOR col IN SELECT * FROM information_schema.columns WHERE table_name = TG_RELNAME LOOP
          new_value := NULL;
          old_value := NULL;
          column_name := col.column_name;
          IF TG_RELNAME = '#{users_table_name}' AND column_name = '#{users_access_column}' THEN
            NULL;
          ELSE
            IF TG_OP = 'INSERT' OR TG_OP = 'UPDATE' THEN
              EXECUTE 'SELECT CAST($1 . '|| column_name ||' AS TEXT)' INTO new_value USING NEW;
              IF primary_key_value IS NULL AND primary_key_column IS NOT NULL THEN
                EXECUTE 'SELECT CAST($1 . '|| primary_key_column ||' AS VARCHAR)' INTO primary_key_value USING NEW;
              END IF;
            END IF;
            IF TG_OP = 'DELETE' OR TG_OP = 'UPDATE' THEN
              EXECUTE 'SELECT CAST($1 . '|| column_name ||' AS TEXT)' INTO old_value USING OLD;
              IF primary_key_value IS NULL AND primary_key_column IS NOT NULL THEN
                EXECUTE 'SELECT CAST($1 . '|| primary_key_column ||' AS VARCHAR)' INTO primary_key_value USING OLD;
              END IF;
            END IF;

            IF TG_OP != 'UPDATE' OR new_value != old_value OR (TG_OP = 'UPDATE' AND ( (new_value IS NULL AND old_value IS NOT NULL) OR (new_value IS NOT NULL AND old_value IS NULL))) THEN
              INSERT INTO audit_log("operation",
                                    "table_name",
                                    "primary_key",
                                    "field_name",
                                    "field_value_old",
                                    "field_value_new",
                                    "user_id",
                                    "user_unique_name",
                                    "occurred_at"
                                   )
              VALUES(TG_OP,
                    TG_RELNAME,
                    primary_key_value,
                    column_name,
                    old_value,
                    new_value,
                    user_identifier,
                    unique_name,
                    current_timestamp);
            END IF;
          END IF;
        END LOOP;
        RETURN NULL;
      END
      $_$;
  SQL
end

.installed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pg_audit_log/function.rb', line 131

def installed?
  connection.select_values(<<-SQL).first.to_i == 1
    SELECT COUNT(pg_proc.proname)
    FROM pg_proc
    WHERE pg_proc.proname = '#{name}'
  SQL
end

.name ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 6

def name
  'audit_changes'
end

.pg_audit_log_old_style_user_id ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 26

def pg_audit_log_old_style_user_id
  defined?(Rails) && Rails.configuration.pg_audit_log_old_style_user_id rescue false
end

.uninstall ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 127

def uninstall
  execute "DROP FUNCTION IF EXISTS #{name}() CASCADE"
end

.user_id_field ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 14

def user_id_field
  'user_id'
end

.user_identifier_temporary_function(user_id) ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 30

def user_identifier_temporary_function(user_id)
  if pg_audit_log_old_style_user_id
    "SET audit.user_id = #{user_id || -1};"
  else
    "CREATE OR REPLACE FUNCTION pg_temp.pg_audit_log_user_identifier() RETURNS integer AS 'SELECT #{user_id}' LANGUAGE SQL STABLE;"
  end
end

.user_name_field ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 18

def user_name_field
  'user_unique_name'
end

.user_unique_name_temporary_function(username) ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 38

def user_unique_name_temporary_function(username)
  if pg_audit_log_old_style_user_id
    "SET audit.user_unique_name = '#{PGconn.escape_bytea(username)}';"
  else
    "CREATE OR REPLACE FUNCTION pg_temp.pg_audit_log_user_unique_name() RETURNS varchar AS $_$ SELECT '#{PGconn.escape_bytea(username)}'::varchar $_$ LANGUAGE SQL STABLE;"
  end
end

.users_access_column ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 22

def users_access_column
  'last_accessed_at'
end

.users_table_name ⇒ Object 



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# File 'lib/pg_audit_log/function.rb', line 10

def users_table_name
  'users'
end