diff options
| -rw-r--r-- | src/corelib/fpg_csvparser.pas | 320 | ||||
| -rw-r--r-- | src/corelib/gdi/fpgui_toolkit.lpk | 10 | ||||
| -rw-r--r-- | src/corelib/gdi/fpgui_toolkit.pas | 3 | ||||
| -rw-r--r-- | src/corelib/x11/fpgui_toolkit.lpk | 10 | ||||
| -rw-r--r-- | src/corelib/x11/fpgui_toolkit.pas | 3 | ||||
| -rw-r--r-- | src/gui/fpg_stringgridbuilder.pas | 178 |
6 files changed, 520 insertions, 4 deletions
diff --git a/src/corelib/fpg_csvparser.pas b/src/corelib/fpg_csvparser.pas new file mode 100644 index 00000000..f5c0d0ed --- /dev/null +++ b/src/corelib/fpg_csvparser.pas @@ -0,0 +1,320 @@ +{ + fpGUI - Free Pascal GUI Toolkit + + Copyright (C) 2006 - 2014 See the file AUTHORS.txt, included in this + distribution, for details of the copyright. + + See the file COPYING.modifiedLGPL, included in this distribution, + for details about redistributing fpGUI. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + + Description: + Uses a Finite State Machine to parse CSV files. + Graeme Geldenhuys <graemeg@gmail.com> + + This unit shows how one could use the State Design Pattern to implement a + FSM (Finite State Machine) to create a CSV Parser. It handles invalid + CSV as well and will raise an appropriate exception. In the State pattern, + each of the states becomes a subclass of the base class. Each subclass must + implement the abstract method which will handle the input character and + decide on the next state. +} + +unit fpg_CSVParser; + +{$mode objfpc}{$H+} + +interface + +uses + Classes; + +type + { forward declarations } + TCSVParser = class; + TParserStateClass = class of TCSVParserState; + + + { Abstract State object } + TCSVParserState = class(TObject) + private + FParser: TCSVParser; + procedure ChangeState(NewState: TParserStateClass); + procedure AddCharToCurrField(Ch: char); + procedure AddCurrFieldToList; + public + constructor Create(AParser: TCSVParser); + { Must be implemented in the concrete classes to handle the input character + and decide on the next state. } + procedure ProcessChar(Ch: AnsiChar; Pos: integer); virtual; abstract; + end; + + + { A concrete state object - used when starting a new field } + TCSVParserFieldStartState = class(TCSVParserState) + public + procedure ProcessChar(Ch: AnsiChar; Pos: integer); override; + end; + + + { A concrete state object - used while scanning a field } + TCSVParserScanFieldState = class(TCSVParserState) + public + procedure ProcessChar(Ch: AnsiChar; Pos: integer); override; + end; + + + { A concrete state object - used while scanning double quoted fields } + TCSVParserScanQuotedState = class(TCSVParserState) + public + procedure ProcessChar(Ch: AnsiChar; Pos: integer); override; + end; + + + { A concrete state object - used when found the ending double quote } + TCSVParserEndQuotedState = class(TCSVParserState) + public + procedure ProcessChar(Ch: AnsiChar; Pos: integer); override; + end; + + + { A concrete state object - some error occured / invalid CSV structure } + TCSVParserGotErrorState = class(TCSVParserState) + public + procedure ProcessChar(Ch: AnsiChar; Pos: integer); override; + end; + + + { The actual state machine - CSV parser } + TCSVParser = class(TObject) + private + FCurrentLine: string; + FState: TCSVParserState; + { Cache state objects for greater performance. This comes in handy when + parsing a large CSV file. For smaller files you might want to create them + on the fly. } + FFieldStartState: TCSVParserFieldStartState; + FScanFieldState: TCSVParserScanFieldState; + FScanQuotedState: TCSVParserScanQuotedState; + FEndQuotedState: TCSVParserEndQuotedState; + FGotErrorState: TCSVParserGotErrorState; + { Fields used during parsing } + FCurrField: string; + FFieldList: TStrings; + function GetState: TParserStateClass; + procedure SetState(const Value: TParserStateClass); + protected + procedure AddCharToCurrField(Ch: char); + procedure AddCurrFieldToList; + { An example of Self Encapsulating Field refactoring } + property State: TParserStateClass read GetState write SetState; + public + constructor Create; + destructor Destroy; override; + { prodecure to call, to start the parsing process } + procedure ExtractFields(const S: string; const pFieldList: TStrings); + property CurrentLine: string read FCurrentLine; + end; + + +// global singleton function +function gCSVParser: TCSVParser; + + +implementation + +uses + SysUtils; + +var + uCSVParser: TCSVParser; + + +// Lazy mans singleton +function gCSVParser: TCSVParser; +begin + if uCSVParser = nil then + uCSVParser := TCSVParser.Create; + Result := uCSVParser; +end; + +{ TCSVParser } + +constructor TCSVParser.Create; +begin + inherited Create; + FCurrentLine := ''; + FFieldStartState := TCSVParserFieldStartState.Create(Self); + FScanFieldState := TCSVParserScanFieldState.Create(Self); + FScanQuotedState := TCSVParserScanQuotedState.Create(Self); + FEndQuotedState := TCSVParserEndQuotedState.Create(Self); + FGotErrorState := TCSVParserGotErrorState.Create(Self); +end; + +destructor TCSVParser.Destroy; +begin + FFieldStartState.Free; + FScanFieldState.Free; + FScanQuotedState.Free; + FEndQuotedState.Free; + FGotErrorState.Free; + inherited; +end; + +function TCSVParser.GetState: TParserStateClass; +begin + Result := TParserStateClass(FState.ClassType); +end; + +procedure TCSVParser.SetState(const Value: TParserStateClass); +begin + if Value = TCSVParserFieldStartState then + FState := FFieldStartState + else if Value = TCSVParserScanFieldState then + FState := FScanFieldState + else if Value = TCSVParserScanQuotedState then + FState := FScanQuotedState + else if Value = TCSVParserEndQuotedState then + FState := FEndQuotedState + else if Value = TCSVParserGotErrorState then + FState := FGotErrorState; +end; + +procedure TCSVParser.ExtractFields(const S: string; const pFieldList: TStrings); +var + i: integer; + Ch: AnsiChar; +begin + FCurrentLine := S; + FFieldList := pFieldList; + Assert(Assigned(FFieldList), 'FieldList not assigned'); + { Initialize by clearing the string list, and starting in FieldStart state } + FFieldList.Clear; + State := TCSVParserFieldStartState; + FCurrField := ''; + + { Read through all the characters in the string } + for i := 1 to Length(s) do + begin + { Get the next character } + Ch := s[i]; + FState.ProcessChar(Ch, i); + end; + + { If we are in the ScanQuoted or GotError state at the end of the string, + there was a problem with a closing quote. You can add the second if test + for an extra failsafe! } + if (State = TCSVParserScanQuotedState) then + // or (State = TCSVParserGotErrorState) then + raise Exception.Create('Missing closing quote'); + + { If the current field is not empty, add it to the list } + if (FCurrField <> '') then + AddCurrFieldToList; +end; + +procedure TCSVParser.AddCharToCurrField(Ch: char); +begin + FCurrField := FCurrField + Ch; +end; + +procedure TCSVParser.AddCurrFieldToList; +begin + FFieldList.Add(FCurrField); + // Clear the field in preparation for collecting the next one + FCurrField := ''; +end; + +{ TCSVParserState } + +constructor TCSVParserState.Create(AParser: TCSVParser); +begin + inherited Create; + FParser := AParser; +end; + +procedure TCSVParserState.ChangeState(NewState: TParserStateClass); +begin + FParser.State := NewState; +end; + +procedure TCSVParserState.AddCharToCurrField(Ch: char); +begin + FParser.AddCharToCurrField(Ch); +end; + +procedure TCSVParserState.AddCurrFieldToList; +begin + FParser.AddCurrFieldToList; +end; + +{ TCSVParserFieldStartState } + +procedure TCSVParserFieldStartState.ProcessChar(Ch: AnsiChar; Pos: integer); +begin + case Ch of + '"': ChangeState(TCSVParserScanQuotedState); + ',': AddCurrFieldToList; + else + AddCharToCurrField(Ch); + ChangeState(TCSVParserScanFieldState); + end; +end; + +{ TCSVParserScanFieldState } + +procedure TCSVParserScanFieldState.ProcessChar(Ch: AnsiChar; Pos: integer); +begin + if (Ch = ',') then + begin + AddCurrFieldToList; + ChangeState(TCSVParserFieldStartState); + end + else + AddCharToCurrField(Ch); +end; + +{ TCSVParserScanQuotedState } + +procedure TCSVParserScanQuotedState.ProcessChar(Ch: AnsiChar; Pos: integer); +begin + if (Ch = '"') then + ChangeState(TCSVParserEndQuotedState) + else + AddCharToCurrField(Ch); +end; + +{ TCSVParserEndQuotedState } + +procedure TCSVParserEndQuotedState.ProcessChar(Ch: AnsiChar; Pos: integer); +begin + if (Ch = ',') then + begin + AddCurrFieldToList; + ChangeState(TCSVParserFieldStartState); + end + else + ChangeState(TCSVParserGotErrorState); +end; + +{ TCSVParserGotErrorState } + +procedure TCSVParserGotErrorState.ProcessChar(Ch: AnsiChar; Pos: integer); +begin + raise Exception.Create(Format('Error in line at position %d: ' + #10 + + '<%s>', [Pos, FParser.CurrentLine])); +end; + + +initialization + uCSVParser := nil; + +finalization + if uCSVParser <> nil then + uCSVParser.Free; + +end. + diff --git a/src/corelib/gdi/fpgui_toolkit.lpk b/src/corelib/gdi/fpgui_toolkit.lpk index f07e97c0..487a5e06 100644 --- a/src/corelib/gdi/fpgui_toolkit.lpk +++ b/src/corelib/gdi/fpgui_toolkit.lpk @@ -31,7 +31,7 @@ <Description Value="fpGUI Toolkit"/> <License Value="LGPL 2 with static linking exception."/> <Version Major="1" Minor="3"/> - <Files Count="105"> + <Files Count="107"> <Item1> <Filename Value="..\stdimages.inc"/> <Type Value="Include"/> @@ -452,6 +452,14 @@ <Filename Value="..\..\gui\fpg_toggle.pas"/> <UnitName Value="fpg_toggle"/> </Item105> + <Item106> + <Filename Value="..\..\gui\fpg_stringgridbuilder.pas"/> + <UnitName Value="fpg_StringGridBuilder"/> + </Item106> + <Item107> + <Filename Value="..\fpg_csvparser.pas"/> + <UnitName Value="fpg_CSVParser"/> + </Item107> </Files> <LazDoc Paths="..\..\..\docs\xml\corelib;..\..\..\docs\xml\corelib\x11;..\..\..\docs\xml\corelib\gdi;..\..\..\docs\xml\gui"/> <RequiredPkgs Count="1"> diff --git a/src/corelib/gdi/fpgui_toolkit.pas b/src/corelib/gdi/fpgui_toolkit.pas index a20c428f..4704d56a 100644 --- a/src/corelib/gdi/fpgui_toolkit.pas +++ b/src/corelib/gdi/fpgui_toolkit.pas @@ -22,7 +22,8 @@ uses fpg_style_win2k, fpg_style_motif, fpg_style_clearlooks, fpg_style_bluecurve, fpg_style_bitmap, fpg_readonly, fpg_imgfmt_png, U_Command, U_Pdf, U_Report, U_ReportImages, U_Visu, fpg_trayicon, Agg2D, fpg_dbugintf, fpg_dbugmsg, - fpg_style_carbon, fpg_style_plastic, fpg_style_win8, fpg_toggle; + fpg_style_carbon, fpg_style_plastic, fpg_style_win8, fpg_toggle, + fpg_StringGridBuilder, fpg_CSVParser; implementation diff --git a/src/corelib/x11/fpgui_toolkit.lpk b/src/corelib/x11/fpgui_toolkit.lpk index b46195d4..e59e4617 100644 --- a/src/corelib/x11/fpgui_toolkit.lpk +++ b/src/corelib/x11/fpgui_toolkit.lpk @@ -29,7 +29,7 @@ <Description Value="fpGUI Toolkit"/> <License Value="LGPL 2 with static linking exception."/> <Version Major="1" Minor="3"/> - <Files Count="108"> + <Files Count="110"> <Item1> <Filename Value="../stdimages.inc"/> <Type Value="Include"/> @@ -462,6 +462,14 @@ <Filename Value="../../gui/fpg_toggle.pas"/> <UnitName Value="fpg_toggle"/> </Item108> + <Item109> + <Filename Value="../../gui/fpg_stringgridbuilder.pas"/> + <UnitName Value="fpg_StringGridBuilder"/> + </Item109> + <Item110> + <Filename Value="../fpg_csvparser.pas"/> + <UnitName Value="fpg_CSVParser"/> + </Item110> </Files> <LazDoc Paths="../../../docs/xml/corelib;../../../docs/xml/corelib/x11;../../../docs/xml/corelib/gdi;../../../docs/xml/gui"/> <RequiredPkgs Count="1"> diff --git a/src/corelib/x11/fpgui_toolkit.pas b/src/corelib/x11/fpgui_toolkit.pas index 429d3497..be9f3b5a 100644 --- a/src/corelib/x11/fpgui_toolkit.pas +++ b/src/corelib/x11/fpgui_toolkit.pas @@ -23,7 +23,8 @@ uses fpg_style_bluecurve, fpg_style_bitmap, fpg_readonly, fpg_imgfmt_png, U_Command, U_Pdf, U_Report, U_ReportImages, U_Visu, fpg_trayicon, Agg2D, fpg_dbugintf, fpg_dbugmsg, fpg_fontcache, fpg_style_carbon, - fpg_style_plastic, fpg_style_win8, fpg_scrollframe, fpg_toggle; + fpg_style_plastic, fpg_style_win8, fpg_scrollframe, fpg_toggle, + fpg_StringGridBuilder, fpg_CSVParser; implementation diff --git a/src/gui/fpg_stringgridbuilder.pas b/src/gui/fpg_stringgridbuilder.pas new file mode 100644 index 00000000..fd3fe3b8 --- /dev/null +++ b/src/gui/fpg_stringgridbuilder.pas @@ -0,0 +1,178 @@ +{ + fpGUI - Free Pascal GUI Toolkit + + Copyright (C) 2006 - 2014 See the file AUTHORS.txt, included in this + distribution, for details of the copyright. + + See the file COPYING.modifiedLGPL, included in this distribution, + for details about redistributing fpGUI. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + + Description: + This unit defines a helper class that can populate a StringGrid + from a CSV file. In future this could be expaned to other file + types or even data structures. +} +unit fpg_StringGridBuilder; + +{$mode objfpc}{$H+} + +interface + +uses + Classes, + SysUtils, + fpg_base, + fpg_grid; + +type + TStringGridBuilder = class(TObject) + private + FData: TStringList; + FGrid: TfpgStringGrid; + FCSVFile: TfpgString; + FHasHeader: boolean; + protected + procedure InternalSetupColumns; virtual; + procedure InternalSetupData; virtual; + procedure InternalRepaintRow(const AData: TfpgString; const ARow: integer); virtual; + public + constructor Create; + constructor CreateCustom(const AGrid: TfpgStringGrid; const ACSVFile: TfpgString; const AWithHeader: boolean = True); virtual; + destructor Destroy; override; + procedure Run; + property Grid: TfpgStringGrid read FGrid; + end; + +implementation + +uses + fpg_main, + fpg_utils, + fpg_CSVParser; + +{ TStringGridBuilder } + +procedure TStringGridBuilder.InternalSetupColumns; +var + x: integer; + fields: TStringList; +begin + fields := TStringList.Create; + try + gCsvParser.ExtractFields(FData[0], fields); + // setup correct column count + FGrid.ColumnCount := fields.Count; + // initialize columns + if FHasHeader then + begin + for x := 0 to fields.Count-1 do + begin + FGrid.ColumnTitle[x] := fields[x]; +// FGrid.ColumnWidth[x] := StrToInt(FColumns.ValueFromIndex[x]); + end; + end; + finally + fields.Free; + end; +end; + +procedure TStringGridBuilder.InternalSetupData; +var + y: integer; +begin + FGrid.BeginUpdate; + FGrid.MouseCursor := mcHourGlass; + try + try + // set correct row count. Columns have already been handled. + if FHasHeader then + begin + FGrid.RowCount := FData.Count-1; + for y := 1 to FData.Count-1 do // rows + begin + // writeln(' Row: ', y, ' Data: ', FData.Strings[y-1]); + InternalRepaintRow(FData.Strings[y], y-1); + end; + end + else + begin + FGrid.RowCount := FData.Count; + for y := 0 to FData.Count-1 do // rows + begin + // writeln(' Row: ', y, ' Data: ', FData.Strings[y-1]); + InternalRepaintRow(FData.Strings[y], y); + end; + end; + except + fpgApplication.HandleException(self); + end; + finally + if FGrid.RowCount > 0 then + FGrid.FocusRow := 0; + FGrid.EndUpdate; + FGrid.MouseCursor := mcDefault; + end; +end; + +procedure TStringGridBuilder.InternalRepaintRow(const AData: TfpgString; const ARow: integer); +var + x: integer; + fields: TStrings; + value: string; +begin + fields := TStringList.Create; + try + gCsvParser.ExtractFields(AData, fields); + for x := 0 to FGrid.ColumnCount-1 do + begin + if x < fields.Count then + value := fields.Strings[x] + else + value := ''; + FGrid.Cells[x, ARow] := value + end; + finally + fields.Free; + end; +end; + +constructor TStringGridBuilder.Create; +begin + FData := TStringList.Create; +end; + +constructor TStringGridBuilder.CreateCustom(const AGrid: TfpgStringGrid; const ACSVFile: TfpgString; const AWithHeader: boolean); +begin + Create; + FGrid := AGrid; + FCSVFile := ACSVFile; + FGrid.Clear; + FHasHeader := AWithHeader; + FGrid.ShowHeader := AWithHeader; +end; + +destructor TStringGridBuilder.Destroy; +begin + FGrid := nil; + FData.Free; + inherited Destroy; +end; + +procedure TStringGridBuilder.Run; +begin + if FCSVFile = '' then + raise Exception.Create('TStringGridBuilder: CSV filename is empty!'); + if not fpgFileExists(FCSVFile) then + raise Exception.CreateFmt('TStringGridBuilder: The CSV file <%s> does not exist.', [FCSVFile]); + FData.LoadFromFile(fpgToOSEncoding(FCSVFile)); + InternalSetupColumns; + InternalSetupData; +end; + + +end. + |