{
* Web.UCharEncodings.pas
*
* Implements a class that defines and provides access to character sets and
* encodings supported when accessing web services.
*
* $Rev$
* $Date$
*
* ***** 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 Web.UCharEncodings.pas, formerly
* NsWebServices.UCharEncodings.pas.
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2010 Peter
* Johnson. All Rights Reserved.
*
* Contributor(s)
* NONE
*
* ***** END LICENSE BLOCK *****
}
unit Web.UCharEncodings;
interface
uses
// Project
UEncodings, UIStringList;
type
/// <summary>
/// Static class that provies access to character sets and their associated
/// encodings supported when accessing web servers.
/// </summary>
TWebCharEncodings = class(TEncodingHelper)
strict private
/// Character set used when none is specified.
const DefaultEncoding = 'ISO-8859-1';
/// List of supported character sets.
class var fSupportedCharSets: IStringList;
strict protected
/// <summary>
/// Checks if a named character set is in the list of supported character
/// sets.
/// </summary>
class function IsWantedCharSet(const CharSet: string): Boolean; override;
public
/// <summary>
/// Creates list of supported encodings.
/// </summary>
class constructor Create;
/// <summary>
/// Returns command separated list of accepted character set names suitable
/// for inclusion in HTTP headers.
/// </summary>
class function AcceptCharSet: string;
/// <summary>
/// Returns name of character set to use by default when empty string is
/// specified as a character set name.
/// </summary>
/// <returns>Required default character set name.</returns>
class function DefaultCharSet: string; override;
end;
implementation
{ TWebCharEncodings }
class function TWebCharEncodings.AcceptCharSet: string;
var
CharSet: string;
begin
Result := '';
for CharSet in CharSets do
begin
if Result <> '' then
Result := Result + ', ';
Result := Result + CharSet;
end;
end;
class constructor TWebCharEncodings.Create;
begin
fSupportedCharSets := TIStringList.Create(
['UTF-8', 'UTF-16LE', 'UTF-16BE', 'ISO-8859-1', 'Windows-1252', 'ASCII']
);
// NOTE: UTF-16 has been left out because some problems with PHP's
// mb_convert_encoding() with UTF-16 have been found, so it's not safe to
// accept this encoding
end;
class function TWebCharEncodings.DefaultCharSet: string;
begin
Result := ISO88591CharSetName;
end;
class function TWebCharEncodings.IsWantedCharSet(const CharSet: string):
Boolean;
begin
Result := fSupportedCharSets.Contains(CharSet);
end;
end.
