How can I get type of column in postgresql trigger function

I want to get type of column from postgresql trigger function.

This query returns type of items:

Select pg_typeof(shape) from sde.my_points;

And this query returns type of geometry:

Select  GeometryType(shape) from sde.my_points;

I want to use this parts in postgresql trigger function:

 CREATE FUNCTION point_xy() RETURNS trigger AS $point_xy$
        BEGIN
                IF (SELECT pg_typeof(NEW.shape)) = ('geometry')
                   AND  GeometryType(NEW.shape) = ('POINT')
                THEN
                        NEW.x = st_x(NEW.shape);
                        NEW.y = st_y(NEW.shape);
                END IF;
            END IF;

            RETURN NEW;
        END
        $point_xy$ LANGUAGE plpgsql;

This function gives error, in this line (SELECT pg_typeof(NEW.shape)).

ERROR: invalid input syntax for type oid: "geometry"

QUERY: SELECT (SELECT pg_typeof(NEW.shape)) = ('geometry') AND GeometryType(NEW.shape) = ('POINT')

CONTEXT: PL/pgSQL function point_xy() line 7

How can I use in function?