[Lazarus] Iterate TStringToStringTree

[Mattias Gaertner]

You may want to look at the TDBF component. I think the package is called
lazdbf or dbflaz.

Michael.

On Tue, 15 Jun 2010, Peter E Williams wrote:

> Hi All,
>
> I really need to know what is the Dbase3/4 unit for Lazarus/Free Pascal
> and where is the sample project for manipulating them. I found it
> somewhere on the lazarus website but don't know where. I hope that it is
> okay for me to post some of my code which uses the XBase1 unit in Delphi
> 5 Enterprise which I am porting to my Hexxpawn8 game (which is cross
> platform open source).
>
> I use Dbase3/4+ files to store board patterns for my game which is sort
> of a cross between the pawns in Chess and checkers, using AI logic
> against the computer. (I chose Dbase format because it was the single
> most common database file format at the time.)
>
> What is the replacement unit for XBase1 for using Dbase3/4 files, and
> the functions/procedures etc to replace these calls to XBase1 ?
>
> How do I do the following:
>
> // declaring a Dbase file -- TXBase (what is the equivalent in Lazarus?)
> // how do I copy a blank.dfg file to hex8.bdf (Copyfile) ???
> // I need to Goto to the Bottom of File (HexxData.GotoBOF;)
> // I need to call a function GetFieldByName passing a string as the
> field name and comparing it with a character
> // I need to Goto the Next record (HexxData.GotoNext;)
> // I need to Get the Record # (HexxData.RecNo;)
> // and test the Dbase.EOF (not HexxData.EOF)
> // and Append a Blank record (HexxData.AppendBlank;)
> // save an integer to a Field (HexxData.UpdFieldStr('this_game',
> inttostr(pattern.this_game)); )
> // and Goto to the Record number (HexxData.GotoRecord(hexxdata_rec_no);)
>
> See examples of my code below
>
> Unit hexboard2.pas
>
> // declaring a Dbase file -- TXBase
> var
>  HexxData, TraceFile: TXBase;
>
> procedure Thxboard.Open_db;
> begin
>  if not fileExists('hex8.dbf') then
>    CopyFile('blank.dbf', 'hex8.dbf', false);
> // how do I copy a blank.dfg file to hex8.bdf ???
>
>  HexxData := TXBase.create(nil);
> // I assume that this is how to create a replacement for a Dbase file
>  HexxData.FileName := 'hex8.dbf';
>  HexxData.Active := true;
>  HexxData.GotoBOF;
> // I need to Goto to the Bottom of File
> end; { Open_db }
>
> function Thxboard.pattern_is_db_current(pattern1: pattern_type):
> boolean;
> var
>  str_x, str_o: array[1..8] of string;
> begin
>  pattern_is_db_current := false;
>  str(pattern1.x_piece[1], str_x[1]);
> // ..
>  if (HexxData.GetFieldByName('x1_pos') = str_x[1]) and
>
> // I need to call a function GetFieldByName passing a string as the
> field name and comparing it with a character
>
> //..
>    (HexxData.GetFieldByName('x8_pos') = str_x[8]) then
>    if (HexxData.GetFieldByName('o1_pos') = str_o[1]) and
> //..
>      (HexxData.GetFieldByName('o8_pos') = str_o[8]) then
>      pattern_is_db_current := true;
> end; { pattern_is_db_current }
> {---------------------------------------------------------}
>
> procedure Thxboard.Find_pattern(var pattern1: pattern_type;
>  var found: boolean);
> begin
> //,,
>        HexxData.GotoNext;
>
> // I need to Goto the Next record
>
> end; { Find_pattern }
> {---------------------------------------------------------}
>
> procedure Thxboard.write_updated_pattern(var pattern1: pattern_type);
> var
>  found: boolean;
> begin
>  found := false;
>  if pattern_is_db_current(pattern1) then
>    { save pattern options to db }
>    begin
>      save_options(pattern1);
>
>      hexxdata_rec_no := HexxData.RecNo;
> // I need to Get the Record #
>      close_db;
>      if trace_moves then
> //..
>      open_db;
>      HexxData.GotoRecord(hexxdata_rec_no);
> // then I need to Goto to record #
>    end
>  else
>  { save entire pattern to db };
>  begin
>    while (not HexxData.EOF) and not found do
>
> // and test the Dbase.EOF (end of file)
>      begin
> //..
>      end;
>    if not found then
>      begin
>      { --- add a new record --- }
>        HexxData.AppendBlank;
>
> // and Append a Blank record
>
>        save_options(pattern1);
>        HexxData.UpdFieldStr('this_game', inttostr(pattern.this_game));
>
> // save an integer to a Field
>
> //..
>        hexxdata_rec_no := HexxData.RecNo;
>        close_db;
>        if trace_moves then
> //..
> 	open_db;
>        HexxData.GotoRecord(hexxdata_rec_no);
> // and Goto to the Record number
>      end; // if found
>  end; // else
> end; { write_updated_pattern  }
> {---------------------------------------------------------}
> -- 
> Proudly developing Quality Cross Platform Open Source Games
> Since 1970 with a Commodore PET 4016 with 16 KRAM
> http://pews-freeware-games.org (<--- brand new)
>
>
> --
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