= Drawing Code Handling =

 1. Drawing codes are composed of components, each of which (generally) has a meaning)
 1. The drawing code components can be mapped to classification (and other fields) in the Drawings record.
    * Maps may be direct (to reference tables) or via drawing code map tables (see below)
 1. There is a complex syntax described in SomePage (?)
    * Drawing codes are specified in app/settings/DrawingCode.php
    * And their functionality is implemented in app/lib/DrawingCodeBase.php

== Mapping from Drawing Code Components to Classifications ==

 1. Uses the following tables:

    * DrawingCodeMapRef - Defines a drawing code component map (basically its name and id)
    * DrawingCodeMapCodes - Defines the code values allowed for the drawing code component
    * DrawingCodeMapValues - Defines mapping from the drawing code component values to classification id values

== Example ==

Example component ''languageCode'' for a MET drawing code:

 1. In !DrawingCodeMapRef:
    * id=1002, name='Language Code'
 2. In !DrawingCodeMapCodes:
    * EN - English
    * EH - English/Hungarian
    * HU - Hungarian
 3. In !DrawingCodeMapValues, if these codes mapped to a classification (which currently they do not), we 
    can put (nultiple) mappings of target (field, value) tuples. Note that the field refers to the form (? '''check this''')

    *  HU --> Drawings.languageId, 3 (3=Hungarian)

Note that this is not yet implemented for V12.x, e.g. for aspect based classifications.