MDX( ) example

The following utility function generates a program file that will recreate all indexes from scratch. This generated program also documents the index tags. It uses the MDX( ) function to get the name of the .MDX file that contains the active index tag. If there is no active index tag, the production .MDX is used. Please note that this program does not take into account primary and distinct indexes.

PROCEDURE GenMDX( cFile )

local cMdx, cMdxFile 

cMdx = mdx( ) 

if cMdx == "" 

*-- If no active index tag, try production .MDX 

cMdx = mdx( 1 ) 

if cMdx == "" 

msgbox( "No MDX file", "Nothing to do", 48 ) 

return  

endif 

endif 

*-- Set OF clause for non-production .MDX 

cMdxFile = iif( cMdx == mdx( 1 ), "", [ of "] + cMdx + ["] ) 

*-- Remove drive and/or path from .MDX filename 

*-- (after setting OF clause, because that checks cMdx) 

cMdx = substr( cMdx, max( rat( ":", cMdx ), rat( "\", cMdx ) ) + 1 ) 

local lSafety 

lSafety = ( set( "SAFETY" ) == "ON" ) 

set safety on 

if argcount( ) < 1 

cFile = left( cMdx, rat( ".", cMdx ) - 1 ) + "X.PRG" 

endif 

set alternate to ( cFile ) 

set console off 

? 

set alternate on 

??"* " + cFile 

? "*" 

? "* Index file for " + cMdx 

if cMdxFile == "" 

?? " (production .MDX)" 

endif 

? "*" 

? "* Generated on " + dtoc( date( ) ) + " " + time( ) 

? "*" 

? 

? [*-- Delete all current tags from specific .MDX only] 

? [do while "" # tag( "] + cMdx + [", 1 )] 

? [ delete tag tag( "] + cMdx + [", 1 )] 

? [enddo] 

? 

nNdx = 1 

do while "" # key( cMdx, nNdx ) 

? [index tag ] + transform( tag( cMdx, nNdx ), "@! XXXXXXXXXX" ) + ; 

cMdxFile + [ on ] + key( cMdx, nNdx ) 

if "" # for( cMdx, nNdx ) 

?? [ for ] + for( cMdx, nNdx ) 

endif 

if descending( cMdx, nNdx ) 

?? [ descending] 

endif 

if unique( cMdx, nNdx ) 

?? [ unique] 

endif 

nNdx = nNdx + 1 

enddo 

close alternate 

if .not. lSafety 

set safety off 

endif 

The function uses the KEY( ), FOR( ), DESCENDING( ), and UNIQUE( ) functions to get the definition of each index.