(a) Municipal codes or revisions may be amended from time to time by ordinances duly enacted and published as required by law and passed in such form as to indicate the intention of the legislative body of the city to make them a part of the code or revision.
(b) When so passed, copies of the ordinances shall be inserted in the copies of the code or revision maintained by the city clerk, and the ordinances shall be deemed a part of the code or revision and shall have the same force and effect as if included therein at the time of the original adoption of the code or revision. However, under this section any amendment shall not be deemed to give any amending ordinance retroactive effect.