= Proposal to implement Named Styles in MapServer =

== Mapfile Extensions ==

 * Enable `STYLE` blocks at the top `MAP` level
   * Add a `NAME` directive to the `STYLE` block
   * Top-level `STYLE` blocks ''must'' be named

 * Provide a "named style" declaration in the `LAYER` block in the form of `LAYER "name"` (in addition to the existing `LAYER ... END` syntax)
   * The `LAYER` object gets instantiated with a ''copy'' of the named style from the top level
   * Referencing a non-existent `STYLE` by name throws an exception

 * Add an `EXTENDS "style"` directive to the `STYLE` block
   * Block styles that inherit from a named style are instantied as a copy of the named style before other declarations in the `STYLE` block are applied

== Proposed Map File Syntax Example ==

{{{
MAP
  STYLE
    NAME "some_style"
    ...
  END
  ...
  LAYER
    NAME "uses_a_style"
    CLASS
       STYLE "some_style"
       ...
    END
  END
  LAYER 
    NAME "extends_a_style"
    CLASS
      STYLE
        EXTENDS "some_style"
        ...
      END
    END
  END
END
}}}


== MapServer `StyleObj` Extensions ==

 * Add a "name" property
 * Add a "global" property
 * Add a "cloneStyle" function to mapfile.c

== MapScript Extensions ==

 * ...