{
* UIniDataLoader.pas
*
* Implements an extension of TMemIniFile that loads the ini data from a set of
* associated files and pre-processes the data.
*
* $Rev$
* $Date$
*
* ***** BEGIN LICENSE BLOCK *****
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
* the specific language governing rights and limitations under the License.
*
* The Original Code is UIniDataLoader.pas
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2009-2012 Peter
* Johnson. All Rights Reserved.
*
* Contributor(s)
* NONE
*
* ***** END LICENSE BLOCK *****
}
unit UIniDataLoader;
interface
uses
// Delphi
Classes, IniFiles,
// Project
UBaseObjects, UExceptions, UIStringList;
type
{
TDatabaseIniFile:
Extension of TMemIniFile that loads the ini data from a set of associated
files. Any quotes enclosing values read from ini file are stripped. Files
are pre-processed, and modified according to any pre-processing directives.
}
TDatabaseIniFile = class(TMemIniFile)
strict private
procedure CopyFileToStream(const FileName: string; const Stream: TStream);
{Appends a file's contents to a stream.
@param FileName [in] Name of file to copy.
@param Stream [in] Stream that receives file's content.
}
procedure CopyFilesToStream(const FileNames: IStringList;
const Stream: TStream);
{Copies content of a list of file to a stream.
@param FileNames [in] List of name of files to be copied
@param Stream [in] Stream that receives files' contents.
}
procedure LoadFromStream(const Stream: TStream);
{Load ini data from a stream.
@param Stream [in] Stream containing ini data.
}
public
constructor Create(const FileName: string);
{Class constructor. Sets up object and loads its data from a set of
associated files.
@param FileName [in] Base file name for associated files containing
data.
}
function ReadString(const Section, Ident, Default: string): string;
override;
{Retrieves a string value from an ini file.
@param Section [in] Section containing desired value.
@param Ident [in] Identifier of desired value.
@param Default [in] Default value used if Ident is not present or not
assigned.
@return Required value, with any enclosing quotes removed.
}
procedure SetStrings(const Strings: IStringList); overload;
{Adapts inherited SetStrings to load data from IStringList instead of
TStringList.
@param Strings [in] Strings to be loaded.
}
end;
{
EDatabaseIniFile:
}
EDatabaseIniFile = class(ECodeSnip);
implementation
uses
// Delphi
SysUtils, StrUtils,
// Project
UVersionInfo;
type
{
TDatabaseFileMapper:
Static class that gets a list of file names associated with a specified file
name. Used to associate database file names visible only to early versions
of CodeSnip with file names visible to later versions.
}
TDatabaseFileMapper = class(TNoConstructObject)
strict private
class function AlternateFileName(const FileName: string): string;
{Creates an alternate file name for a specified file that will be
recognised by v3 of CodeSnip or later.
@param FileName [in] Base file name.
@return Alternate file name.
}
public
class function GetRelatedFiles(const FileName: string): IStringList;
{Builds a list of file names associated with a base file name.
@param FileName [in] Base file name.
@return List of associated files, all of which exist. List may not
include base file name if it doesn't exist.
}
end;
{
TDatabasePreprocessor:
Static class used to pre-process ini file, acting on pre-processor
instructions. Does not support nesting of directives. Supported instructions
are:
#if-ver-eq <version>
Checks if application version is equal to <version>.
#if-ver-neq <version>
Checks if application version is not equal to <version>.
#if-ver-lt <version>
Checks if application version is less than <version>.
#if-ver-gt <version>
Checks if application version is greater than <version>.
#if-ver-inrange <version-lo> <version-hi>
Checks if application version is in the range of versions specified from
<version-lo> to <version-hi>, inclusive.
#end-if
Ends a block started by any of the #if- instructions above.
When a #if- instruction evaluates true then all the following lines in the
ini file up to the #end-if instruction and included. If it evaluates false
the enclosed lines are ignored.
Version numbers are in form 9.9.9.9. Minor version numbers are optional
and are filled with zeroes, so specifying 3 is equivalent to 3.0.0.0 and
2.1 is equivalent to 2.1.0.0.
Unrecognised instructions are ignored and are not included in the output.
}
TDatabasePreprocessor = class(TNoConstructObject)
strict private
type
{
TVerCompareMethod:
Type of methods used to compare version numbers.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if required condition applies, False if not.
}
TVerCompareMethod = function(Ver1, Ver2: TVersionNumber): Boolean
of object;
const
// Symbols that prefix every pre-processor instruction
cPreProcPrefix = ';#';
// Pre-processor instructions / directives
cEndIf = cPreProcPrefix + 'end-if'; // ends if instruction
cIfVerEQ = cPreProcPrefix + 'if-ver-eq'; // appver = param
cIfVerNEQ = cPreProcPrefix + 'if-ver-neq'; // appver <> param
cIfVerLT = cPreProcPrefix + 'if-ver-lt'; // appver < param
cIfVerGT = cPreProcPrefix + 'if-ver-gt'; // appver > param
cIfVerInRange = cPreProcPrefix + 'if-ver-inrange'; // appver in range
class function ProcessVerEQ(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifvereq pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is equal to version
specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing.
Out: index of last line processed.
}
class function ProcessVerNEQ(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifverneq pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is not equal to
version specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing.
Out: index of last line processed.
}
class function ProcessVerLT(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifverlt pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is less than version
specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing.
Out: index of last line processed.
}
class function ProcessVerGT(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifvergt pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is greater than
version specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing.
Out: index of last line processed.
}
class function ProcessVerInRange(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes ifverinrange pre-processor directive. Includes lines before
endif directive only if condition is met, i.e. app version is in range of
version numbers specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current kine before processing.
Out: index of last line processed.
}
class function CompareEQ(Ver1, Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is equal to second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 = Ver2, False if not.
}
class function CompareNEQ(Ver1, Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is not equal to second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 <> Ver2, False if not.
}
class function CompareGT(Ver1, Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is greater than second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 > Ver2, False if not.
}
class function CompareLT(Ver1, Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is less than second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 < Ver2, False if not.
}
class function ProcessVerCompare(const Lines: IStringList;
var LineIdx: Integer; const CompareFn: TVerCompareMethod): IStringList;
{Processes a version comparison directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing.
Out: index of last line processed.
@param CompareFn [in] Method to used to compare application version with
version number read from directive to determine if directive executes.
}
class function ProcessToEndIf(const Lines: IStringList;
var LineIdx: Integer; const RecordLines: Boolean): IStringList;
public
class function PreProcess(Lines: IStringList): IStringList;
{Performs pre-processing.
@param Lines [in] Lines of text to be pre-processed.
@return Lines after preprocessing.
}
end;
{ TDatabaseIniFile }
procedure TDatabaseIniFile.CopyFilesToStream(const FileNames: IStringList;
const Stream: TStream);
{Copies content of a list of file to a stream.
@param FileNames [in] List of name of files to be copied
@param Stream [in] Stream that receives files' contents.
}
var
FileName: string; // each file name in list
begin
for FileName in FileNames do
CopyFileToStream(FileName, Stream);
end;
procedure TDatabaseIniFile.CopyFileToStream(const FileName: string;
const Stream: TStream);
{Appends a file's contents to a stream.
@param FileName [in] Name of file to copy.
@param Stream [in] Stream that receives file's content.
}
var
FS: TFileStream; // stream onto file
begin
FS := TFileStream.Create(FileName, fmOpenRead or fmShareDenyNone);
try
Stream.CopyFrom(FS, FS.Size);
finally
FreeAndNil(FS);
end;
end;
constructor TDatabaseIniFile.Create(const FileName: string);
{Class constructor. Sets up object and loads its data from a set of associated
files.
@param FileName [in] Base file name for associated files containing data.
}
var
Stream: TStream; // Stream that receives data from files
Files: IStringList; // List of associated file names
resourcestring
// Error message
sMissingCatFile = 'Neither category file "%s" nor its alternate exists.';
begin
inherited Create(FileName);
Stream := TMemoryStream.Create;
try
// Get list of file names containing data
Files := TDatabaseFileMapper.GetRelatedFiles(FileName);
if Files.Count = 0 then
raise EDatabaseIniFile.CreateFmt(
sMissingCatFile, [ExtractFileName(FileName)]
);
// Load ini data via intermediate streams
CopyFilesToStream(TDatabaseFileMapper.GetRelatedFiles(FileName), Stream);
Stream.Position := 0;
LoadFromStream(Stream);
finally
FreeAndNil(Stream);
end;
end;
procedure TDatabaseIniFile.LoadFromStream(const Stream: TStream);
{Load ini data from a stream.
@param Stream [in] Stream containing ini data.
}
var
Strings: TStringList; // string list that contains ini data as text
PreProcStrings: IStringList; // string list of data after pre-processing
begin
Strings := TStringList.Create;
try
Strings.LoadFromStream(Stream);
PreProcStrings := TDatabasePreprocessor.PreProcess(
TIStringList.Create(Strings)
);
SetStrings(PreProcStrings);
finally
FreeAndNil(Strings);
end;
end;
function TDatabaseIniFile.ReadString(const Section, Ident,
Default: string): string;
{Retrieves a string value from an ini file.
@param Section [in] Section containing desired value.
@param Ident [in] Identifier of desired value.
@param Default [in] Default value used if Ident is not present or not
assigned.
@return Required value, with any enclosing quotes removed.
}
const
cQuote = '"'; // quote character
begin
// Read string from ini
Result := inherited ReadString(Section, Ident, Default);
// Strip any leading and trailing quotes
if (Length(Result) > 1) and (Result[1] = cQuote)
and (Result[Length(Result)] = cQuote) then
Result := Copy(Result, 2, Length(Result) - 2);
end;
procedure TDatabaseIniFile.SetStrings(const Strings: IStringList);
{Adapts inherited SetStrings to load data from IStringList instead of
TStringList.
@param Strings [in] Strings to be loaded.
}
var
SL: TStringList; // string list use to call inherited method
begin
SL := TStringList.Create;
try
Strings.CopyTo(SL);
SetStrings(SL);
finally
FreeAndNil(SL);
end;
end;
{ TDatabaseFileMapper }
function RemoveFileExt(const FileName: string): string;
{Removes an extension from a file name.
@param FileName [in] File name from which extension is to be removed.
@return File name without extension.
}
begin
if SysUtils.AnsiPos('.', FileName) > 0 then
Result := SysUtils.ChangeFileExt(FileName, '')
else
Result := FileName;
end;
class function TDatabaseFileMapper.AlternateFileName(
const FileName: string): string;
{Creates an alternate file name for a specified file that will be recognised
by v3 of CodeSnip or later.
@param FileName [in] Base file name.
@return Alternate file name.
}
var
BaseName: string; // base of file name without extension
Extension: string; // extension common to all names
const
cV3Ext = '.3'; // first extension for v3 database files
begin
// Get base file name without extension
Extension := ExtractFileExt(FileName);
BaseName := RemoveFileExt(ExtractFileName(FileName));
// Build alternate file name
Result := ExtractFilePath(FileName) + BaseName + cV3Ext + Extension;
end;
class function TDatabaseFileMapper.GetRelatedFiles(
const FileName: string): IStringList;
{Builds a list of file names associated with a base file name.
@param FileName [in] Base file name.
@return List of associated files, all of which exist. List may not include
base file name if it doesn't exist.
}
var
AltFileName: string; // an alternate file name
begin
Result := TIStringList.Create;
if FileExists(FileName) then
Result.Add(FileName);
AltFileName := AlternateFileName(FileName);
if (AltFileName <> '') and FileExists(AltFileName) then
Result.Add(AltFileName);
end;
{ TDatabasePreprocessor }
class function TDatabasePreprocessor.CompareEQ(Ver1,
Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is equal to second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 = Ver2, False if not.
}
begin
Result := Ver1 = Ver2;
end;
class function TDatabasePreprocessor.CompareGT(Ver1,
Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is greater than second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 > Ver2, False if not.
}
begin
Result := Ver1 > Ver2;
end;
class function TDatabasePreprocessor.CompareLT(Ver1,
Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is less than second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 < Ver2, False if not.
}
begin
Result := Ver1 < Ver2;
end;
class function TDatabasePreprocessor.CompareNEQ(Ver1,
Ver2: TVersionNumber): Boolean;
{Compares two version numbers to check if first is not equal to second.
@param Ver1 [in] First version number to compare.
@param Ver2 [in] Second version number to compare.
@return True if Ver1 <> Ver2, False if not.
}
begin
Result := Ver1 <> Ver2;
end;
class function TDatabasePreprocessor.PreProcess(Lines: IStringList):
IStringList;
{Performs pre-processing.
@param Lines [in] Lines of text to be pre-processed.
@return Lines after preprocessing.
}
var
LineIdx: Integer; // indexes each line
Line: string; // trimmed content of a line
begin
Result := TIStringList.Create;
LineIdx := 0;
while LineIdx < Lines.Count do
begin
Line := Trim(Lines[LineIdx]);
// Check for pre-processor instructions
if AnsiStartsStr(cIfVerLT, Line) then
Result.Add(ProcessVerLT(Lines, LineIdx))
else if AnsiStartsStr(cIfVerGT, Line) then
Result.Add(ProcessVerGT(Lines, LineIdx))
else if AnsiStartsStr(cIfVerInRange, Line) then
Result.Add(ProcessVerInRange(Lines, LineIdx))
else if AnsiStartsStr(cIfVerEQ, Line) then
Result.Add(ProcessVerEQ(Lines, LineIdx))
else if AnsiStartsStr(cIfVerNEQ, Line) then
Result.Add(ProcessVerNEQ(Lines, LineIdx))
else if AnsiStartsStr(cPreProcPrefix, Line) then
// ignore unknown pre-proc dirs
else
// no pre-processor, just use trimmed line
Result.Add(Line);
Inc(LineIdx);
end;
end;
class function TDatabasePreprocessor.ProcessToEndIf(const Lines: IStringList;
var LineIdx: Integer; const RecordLines: Boolean): IStringList;
begin
Inc(LineIdx);
Result := TIStringList.Create;
while (LineIdx < Lines.Count) and (Trim(Lines[LineIdx]) <> cEndIf) do
begin
if RecordLines then
Result.Add(Lines[LineIdx]);
Inc(LineIdx);
end;
end;
class function TDatabasePreprocessor.ProcessVerCompare(const Lines: IStringList;
var LineIdx: Integer; const CompareFn: TVerCompareMethod): IStringList;
{Processes a version comparison directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing. Out:
index of last line processed.
@param CompareFn [in] Method to used to compare application version with
version number read from directive to determine if directive executes.
}
var
InstParts: IStringList; // parts of the pre-processor instruction
Ver: TVersionNumber; // version number from directive
begin
// Get version number parameter
InstParts := TIStringList.Create(Lines[LineIdx], ' ', False, True);
if InstParts.Count >= 2 then
Ver := InstParts[1] // implicit conversion of string to TVersionNumber
else
Ver := TVersionNumber.Nul; // 0.0.0.0
// Process lines up to endif
Result := ProcessToEndIf(
Lines, LineIdx, CompareFn(TVersionInfo.ProductVerNum, Ver)
);
end;
class function TDatabasePreprocessor.ProcessVerEQ(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifvereq pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is equal to version
specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing. Out:
index of last line processed.
}
begin
Result := ProcessVerCompare(Lines, LineIdx, CompareEQ);
end;
class function TDatabasePreprocessor.ProcessVerGT(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifvergt pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is greater than
version specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing. Out:
index of last line processed.
}
begin
Result := ProcessVerCompare(Lines, LineIdx, CompareGT);
end;
class function TDatabasePreprocessor.ProcessVerInRange(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes ifverinrange pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is in range of version
numbers specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current kine before processing. Out:
index of last line processed.
}
var
InstParts: IStringList; // parts of the pre-processor instruction
VerLo: TVersionNumber; // version number from directive
VerHi: TVersionNumber; // version number from directive
IncludeContents: Boolean; // flag true if enclosed lines to be included
begin
Result := TIStringList.Create;
// Get version number parameter
InstParts := TIStringList.Create(Lines[LineIdx], ' ', False, True);
if InstParts.Count < 3 then
IncludeContents := False
else
begin
VerLo := InstParts[1]; // implicit conversion of string to TVersionNumber
VerHi := InstParts[2]; // implicit conversion of string to TVersionNumber
IncludeContents := (TVersionInfo.ProductVerNum >= VerLo) and
(TVersionInfo.ProductVerNum <= VerHi);
end;
// Process lines up to endif
Result := ProcessToEndIf(Lines, LineIdx, IncludeContents);
end;
class function TDatabasePreprocessor.ProcessVerLT(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifverlt pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is less than version
specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing. Out:
index of last line processed.
}
begin
Result := ProcessVerCompare(Lines, LineIdx, CompareLT);
end;
class function TDatabasePreprocessor.ProcessVerNEQ(const Lines: IStringList;
var LineIdx: Integer): IStringList;
{Processes a ifverneq pre-processor directive. Includes lines before endif
directive only if condition is met, i.e. app version is not equal to version
specified in directive.
@param Lines [in] Lines of ini file.
@param LineIdx [in/out] In: index of current line before processing. Out:
index of last line processed.
}
begin
Result := ProcessVerCompare(Lines, LineIdx, CompareNEQ);
end;
end.
