[GRASS5] Interfaces ... (long)

[Eric G. Miller]

I've made a few of the minor alterations to XML interface that I
previously mentioned.  If everyone is cool with these changes, then I'll
commit them (it will break the proof-of-concept dialog generator that
Jan built).

Changes:

   * There is now a distinct element called "flag" separate from
     "parameter".  It takes an attribute "name", and has an optional
     child element for the "description".

   * Make both "flag" and "parameter" be children of "task" directly.
     This is now the default output, however the DTD still has the
     "parameter-group" with children "description", "parameter", and
     "flag".  It is retained for the future possibility of having
     groups of mutually exclusive options.  I started to implement such
     a thing, but it would require almost a complete rewrite of
     parser.c.

   * Add a "keydesc" element as an optional child of "parameter".  This
     corresponds to the "key_desc" member of an Option struct.  It has
     children called "item", each with an attribute of "order" so that
     the proper ordering can be insured for the "tuple".

   * Add a "gisprompt" element as an optional child of "parameter".
     This is an empty element corresponding to "gisprompt" of the Option
     struct.  It has three required attributes:

       + "age" - The "age" part of the gisprompt argument ("old", "new",
       		"any", or "mapset")
       + "element" - The mapset "element" part of the gisprompt
               	argument ("cell", "dig", "site_lists", etc...)
       + "prompt" -  What should be displayed to the user for a prompt.


Example (s.to.vect --interface-description):

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE task SYSTEM "grass-interface.dtd">
<task name="s.to.vect">
	<description>
		Converts a GRASS site_lists file into a vector file.
	</description>
	<parameter name="input" type="string" required="yes" multiple="no">
		<description>
			Name of site input file
		</description>
		<gisprompt age="old" element="site_lists" prompt="site list" />
	</parameter>
	<parameter name="output" type="string" required="yes" multiple="no">
		<description>
			Name of vector output file
		</description>
		<gisprompt age="new" element="dig" prompt="vector" />
	</parameter>
	<parameter name="cat" type="string" required="no" multiple="no">
		<description>
			Field type ("string", "dim", or "decimal") and index to use for category value (uses "cat" by default)
		</description>
		<keydesc>
			<item order="1">type</item>
			<item order="2">index</item>
		</keydesc>
	</parameter>
	<flag name="p">
		<description>
			Don't prompt for Map header information
		</description>
	</flag>
</task>

-- 
Eric G. Miller <egm2 at jps.net>