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TXBrowse and Filters

Posted: Wed Jan 09, 2008 11:35 am
by ask
Happy new year to all.

How can i modify bskip , bgotop,bgobottom etc. and make my TXBrowse show only the record i want to see?

e.g.
Code Descr
1 ASK
2 Fivetech
3 Software
4 Test

how can i show code>=2 .and. code<=3 ? I DON'T WANT TO USE Setfilter or Ordscope commands.

Thank in advance

A.S.K.


Filter in XBrowse

Posted: Wed Jan 09, 2008 11:53 am
by ukoenig
The best way is, to convert ( if you still using NTX )
to CDX ( Foxpro ).
There is a SCOPE-call ( filter ) for the Index.
That means, when you change the record-position in your
browser, you see only the records, you defined in the SCOPE.
In my sample-collection for xBrowse ( in a few days )
you can see, how it works.

U. König

Posted: Wed Jan 09, 2008 4:18 pm
by Detlef Hoefner
in xHarbour you can use dbfScope functions even with dbfntx rdd.
No need to change to another rdd.

Regards,
Detlef

Posted: Wed Jan 09, 2008 4:35 pm
by James Bott
ASK,

Why would you not want to use scopes? That is what they are for.

Regards,
James

Posted: Wed Jan 09, 2008 5:14 pm
by Biel EA6DD
Like other have suggested, I thing the best and easy solution is using scopes.

If you still don't want to use scope, can do it this way.

Code: Select all

...
   oBrw:bGoTop    := { ||  TopFil( cAlias, cClave ) }
   oBrw:bGoBottom := { ||  Botfil( cAlias, cClave ) }
   oBrw:bSkip     := { | n | SkipFil( cAlias, cClave, n ) }
...
//---------------------------------
FUNCTION SkipFil( cAlias, cKey, nReg )
//---------------------------------
   LOCAL nNext := 0
   DEFAULT nReg := 1
   IF nReg = 0 .OR. ( cAlias ) ->( LastRec() ) = 0 .OR. ! ( &( ( cAlias ) ->( IndexKey( 0 ) ) ) = cKey )
      ( cAlias ) ->( DBSkip( 0 ) )
   ELSEIF nReg > 0 .AND. ( cAlias ) ->( RecNo() ) <> ( cAlias ) ->( LastRec() ) + 1
      DO WHILE nNext <= nReg .AND. ! ( cAlias ) ->( Eof() ) .AND. &( ( cAlias ) ->( IndexKey( 0 ) ) ) = cKey
         ( cAlias ) ->( DBSkip() )
         nNext ++
      ENDDO
      ( cAlias ) ->( DBSkip( - 1 ) )
      nNext --
   ELSEIF nReg < 0
      DO WHILE nNext >= nReg .AND. ! Bof() .AND. &( ( cAlias ) ->( IndexKey( 0 ) ) ) = cKey
         ( cAlias ) ->( DBSkip( - 1 ) )
         nNext --
      ENDDO
      IF ! Bof()
         ( cAlias ) ->( DBSkip() )
      ENDIF
      nNext ++
   ENDIF
   RETURN ( nNext )
//--------------------------
FUNCTION TopFil( cAlias, cKey )
//--------------------------
   ( cAlias ) ->( DBSeek( cKey, .T. ) )
   RETURN NIL
//--------------------------
FUNCTION BotFil( cAlias, cKey )
//--------------------------
   ( cAlias ) ->( DBSeek( Ultima( cKey ), .T. ) )
   ( cAlias ) ->( DBSkip( - 1 ) )
   RETURN NIL
//-----------------------
FUNCTION Ultima( xValue )
//-----------------------
   LOCAL cType := ValType( xValue ), xNext
   DO CASE
   CASE ( cType == "C" )
      xValue := Stuff( xValue, Len( xValue ), 1, ;
                       Chr( Asc( Right( xValue, 1 ) ) + 1 ) )
   CASE ( cType == "N" )
      xValue ++
   CASE ( cType == "D" )
      xValue ++
   ENDCASE
   xNext := xValue
   RETURN( xNext )

Posted: Thu Jan 10, 2008 8:42 am
by ask
ukoenig , Detlef , James , Biel

Thank you all for your reply .The reason that i don't want to use scopes is that i have already allot of source code written with conditions (filters etc) and i want to change my xbrowse to use this conditions and not to change my whole program and start using scopes. As i can see set filter command is very slow. I guess I will try "Biel EA6DD" solution.

Thank you all

A.S.K

Posted: Thu Jan 10, 2008 8:53 am
by StefanHaupt
Ask,

if you are using cdx, you can also try to replace the standard dbfcdx-rdd with bmdbfcdx that comes with xharbour. It´s working with bitmaps filters and it seems to be faster than the original cdx. You don´t need to change any sourcecode, just link in the lib.

Posted: Thu Jan 10, 2008 9:04 am
by ask
Stefan,

I'm using ntx , but thank you anyway.

regards,

A.S.K