current/DataAccess/ConnectionManager.pas

unit ConnectionManager;
interface

uses TypeDefs, DataAccess, Access_OniArchive, Access_OUP_ADB;

type
  TConnections = array of TDataAccess;

  TConnectionListChangedEvent = procedure of object;

  
  TConnectionManager = class
  private
    FConnections: TConnections;
    FLastID:      Integer;
    FConnectionListChanged: TConnectionListChangedEvent;
    function GetConnectionCount: Integer;
    function GetConnection(ConnectionID: Integer): TDataAccess;
    function GetConnectionByIndex(Index: Integer): TDataAccess;
    function GetConnectionIndex(ConnectionID: Integer): Integer;
    procedure RemoveConnection(ArrayIndex: Integer);
  protected
  public
    property Count: Integer read GetConnectionCount;
    property Connection[ConnectionID: Integer]: TDataAccess read GetConnection;
    property ConnectionByIndex[Index: Integer]: TDataAccess read GetConnectionByIndex;
    property ConnectionIndexByID[ConnectionID: Integer]: Integer read GetConnectionIndex;
    property OnCoonnectionListChanged: TConnectionListChangedEvent read FConnectionListChanged write FConnectionListChanged;

    constructor Create;
    function Close: Boolean;

    function OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
    function CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean; overload;
    function CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean; overload;
    function CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean; overload;
  published
  end;


var
  ConManager: TConnectionManager;


implementation
uses
  SysUtils, Dialogs;

(*
 Implementation of TConnectionManager
*)


function TConnectionManager.GetConnectionCount: Integer;
begin
  Result := Length(FConnections);
end;

function TConnectionManager.GetConnectionIndex(ConnectionID: Integer): Integer;
var
  i: Integer;
begin
  Result := -1;
  if Count > 0 then
    for i := 0 to Count - 1 do
      if ConnectionByIndex[i].ConnectionID = ConnectionID then
      begin
        Result := i;
        Break;
      end;
end;

function TConnectionManager.GetConnection(ConnectionID: Integer): TDataAccess;
var
  i: Integer;
begin
  Result := nil;
  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].ConnectionID = ConnectionID then
      begin
        Result := FConnections[i];
        Break;
      end;
    end;
    if i = Length(FConnections) then
      ShowMessage('Couldn''t find specified ConnectionID (' +
          IntToStr(ConnectionID) + '). Please contact developer!!!');
  end;
end;


function TConnectionManager.GetConnectionByIndex(Index: Integer): TDataAccess;
begin
  Result := nil;
  if index < Length(FConnections) then
  begin
    Result := FConnections[index];
  end;
end;

constructor TConnectionManager.Create;
begin
  inherited;
  FLastID := 0;
end;

function TConnectionManager.Close: Boolean;
begin
  Result := False;
  if Length(FConnections) > 0 then
    Exit;

  inherited;
end;


function TConnectionManager.OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
var
  i: Integer;
  ext: String;
  backend: TDataBackend;
  CreateMsg: TStatusMessages;
begin
  Msg := SM_UnknownError;
  Result := -1;

  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].FileName = FileName then
      begin
        Result := FConnections[i].ConnectionID;
        Msg := SM_AlreadyOpened;
        Exit;
      end;
    end;
  end;

  if not FileExists(FileName) then
  begin
    Msg := SM_FileNotFound;
    Exit;
  end;

  ext := UpperCase(ExtractFileExt(FileName));

  if ext = '.OLDB' then
    backend := DB_ADB
  else if ext = '.DAT' then
    backend := DB_ONI
  else
  begin
    Msg := SM_UnknownExtension;
    Exit;
  end;

  SetLength(FConnections, Length(FConnections) + 1);
  i := High(FConnections);
  case backend of
    DB_ONI:
      FConnections[i] := TAccess_OniArchive.Create(FileName, FLastID + 1, CreateMsg);
    DB_ADB:
      FConnections[i] := TAccess_OUP_ADB.Create(FileName, FLastID + 1, CreateMsg);
  end;

  if CreateMsg = SM_OK then
  begin
    FLastID := FConnections[i].ConnectionID;
    Result := FLastID;
    Msg := SM_OK;
  end
  else
  begin
    FConnections[i].Close;
    FConnections[i].Free;
    FConnections[i] := nil;
    SetLength(FConnections, Length(FConnections) - 1);
    Msg := CreateMsg;
  end;
end;


procedure TConnectionManager.RemoveConnection(ArrayIndex: Integer);
var
  i: Integer;
begin
  if Length(FConnections) > 1 then
  begin
    for i := ArrayIndex to High(FConnections) - 1 do
    begin
      FConnections[i] := FConnections[i + 1];
    end;
  end;
  SetLength(FConnections, Length(FConnections) - 1);
end;

function TConnectionManager.CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean;
begin
  Msg := SM_UnknownError;
  Result := False;

  if Index < Length(FConnections) then
  begin
    FConnections[Index].Close;
    RemoveConnection(Index);
    Msg := SM_OK;
    Result := True;
  end;
end;

function TConnectionManager.CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean;
var
  i: Integer;
begin
  Msg := SM_UnknownError;
  Result := False;

  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].ConnectionID = ID then
      begin
        FConnections[i].Close;
        RemoveConnection(i);
        Msg := SM_OK;
        Result := True;
        Exit;
      end;
    end;
  end;
end;

function TConnectionManager.CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean;
var
  i: Integer;
begin
  Msg := SM_UnknownError;
  Result := False;

  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].FileName = FileName then
      begin
        FConnections[i].Close;
        RemoveConnection(i);
        Msg := SM_OK;
        Result := True;
        Exit;
      end;
    end;
  end;
end;


initialization
  ConManager := TConnectionManager.Create;
finalization
  ConManager.Free;
end.
Revision:	109
Committed:	Wed Feb 21 03:12:33 2007 UTC (18 years, 8 months ago) by alloc
Content type:	text/x-pascal
File size:	6378 byte(s)
Log Message:
#	Content
1	unit ConnectionManager;
2	interface
3
4	uses TypeDefs, DataAccess, Access_OniArchive, Access_OUP_ADB;
5
6	type
7	TConnections = array of TDataAccess;
8
9	TConnectionListChangedEvent = procedure of object;
10
11
12	TConnectionManager = class
13	private
14	FConnections: TConnections;
15	FLastID: Integer;
16	FConnectionListChanged: TConnectionListChangedEvent;
17	function GetConnectionCount: Integer;
18	function GetConnection(ConnectionID: Integer): TDataAccess;
19	function GetConnectionByIndex(Index: Integer): TDataAccess;
20	function GetConnectionIndex(ConnectionID: Integer): Integer;
21	procedure RemoveConnection(ArrayIndex: Integer);
22	protected
23	public
24	property Count: Integer read GetConnectionCount;
25	property Connection[ConnectionID: Integer]: TDataAccess read GetConnection;
26	property ConnectionByIndex[Index: Integer]: TDataAccess read GetConnectionByIndex;
27	property ConnectionIndexByID[ConnectionID: Integer]: Integer read GetConnectionIndex;
28	property OnCoonnectionListChanged: TConnectionListChangedEvent read FConnectionListChanged write FConnectionListChanged;
29
30	constructor Create;
31	function Close: Boolean;
32
33	function OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
34	function CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean; overload;
35	function CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean; overload;
36	function CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean; overload;
37	published
38	end;
39
40
41	var
42	ConManager: TConnectionManager;
43
44
45	implementation
46	uses
47	SysUtils, Dialogs;
48
49	(*
50	Implementation of TConnectionManager
51	*)
52
53
54	function TConnectionManager.GetConnectionCount: Integer;
55	begin
56	Result := Length(FConnections);
57	end;
58
59	function TConnectionManager.GetConnectionIndex(ConnectionID: Integer): Integer;
60	var
61	i: Integer;
62	begin
63	Result := -1;
64	if Count > 0 then
65	for i := 0 to Count - 1 do
66	if ConnectionByIndex[i].ConnectionID = ConnectionID then
67	begin
68	Result := i;
69	Break;
70	end;
71	end;
72
73	function TConnectionManager.GetConnection(ConnectionID: Integer): TDataAccess;
74	var
75	i: Integer;
76	begin
77	Result := nil;
78	if Length(FConnections) > 0 then
79	begin
80	for i := 0 to High(FConnections) do
81	begin
82	if FConnections[i].ConnectionID = ConnectionID then
83	begin
84	Result := FConnections[i];
85	Break;
86	end;
87	end;
88	if i = Length(FConnections) then
89	ShowMessage('Couldn''t find specified ConnectionID (' +
90	IntToStr(ConnectionID) + '). Please contact developer!!!');
91	end;
92	end;
93
94
95	function TConnectionManager.GetConnectionByIndex(Index: Integer): TDataAccess;
96	begin
97	Result := nil;
98	if index < Length(FConnections) then
99	begin
100	Result := FConnections[index];
101	end;
102	end;
103
104	constructor TConnectionManager.Create;
105	begin
106	inherited;
107	FLastID := 0;
108	end;
109
110	function TConnectionManager.Close: Boolean;
111	begin
112	Result := False;
113	if Length(FConnections) > 0 then
114	Exit;
115
116	inherited;
117	end;
118
119
120
121	function TConnectionManager.OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
122	var
123	i: Integer;
124	ext: String;
125	backend: TDataBackend;
126	CreateMsg: TStatusMessages;
127	begin
128	Msg := SM_UnknownError;
129	Result := -1;
130
131	if Length(FConnections) > 0 then
132	begin
133	for i := 0 to High(FConnections) do
134	begin
135	if FConnections[i].FileName = FileName then
136	begin
137	Result := FConnections[i].ConnectionID;
138	Msg := SM_AlreadyOpened;
139	Exit;
140	end;
141	end;
142	end;
143
144	if not FileExists(FileName) then
145	begin
146	Msg := SM_FileNotFound;
147	Exit;
148	end;
149
150	ext := UpperCase(ExtractFileExt(FileName));
151
152	if ext = '.OLDB' then
153	backend := DB_ADB
154	else if ext = '.DAT' then
155	backend := DB_ONI
156	else
157	begin
158	Msg := SM_UnknownExtension;
159	Exit;
160	end;
161
162	SetLength(FConnections, Length(FConnections) + 1);
163	i := High(FConnections);
164	case backend of
165	DB_ONI:
166	FConnections[i] := TAccess_OniArchive.Create(FileName, FLastID + 1, CreateMsg);
167	DB_ADB:
168	FConnections[i] := TAccess_OUP_ADB.Create(FileName, FLastID + 1, CreateMsg);
169	end;
170
171	if CreateMsg = SM_OK then
172	begin
173	FLastID := FConnections[i].ConnectionID;
174	Result := FLastID;
175	Msg := SM_OK;
176	end
177	else
178	begin
179	FConnections[i].Close;
180	FConnections[i].Free;
181	FConnections[i] := nil;
182	SetLength(FConnections, Length(FConnections) - 1);
183	Msg := CreateMsg;
184	end;
185	end;
186
187
188	procedure TConnectionManager.RemoveConnection(ArrayIndex: Integer);
189	var
190	i: Integer;
191	begin
192	if Length(FConnections) > 1 then
193	begin
194	for i := ArrayIndex to High(FConnections) - 1 do
195	begin
196	FConnections[i] := FConnections[i + 1];
197	end;
198	end;
199	SetLength(FConnections, Length(FConnections) - 1);
200	end;
201
202	function TConnectionManager.CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean;
203	begin
204	Msg := SM_UnknownError;
205	Result := False;
206
207	if Index < Length(FConnections) then
208	begin
209	FConnections[Index].Close;
210	RemoveConnection(Index);
211	Msg := SM_OK;
212	Result := True;
213	end;
214	end;
215
216	function TConnectionManager.CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean;
217	var
218	i: Integer;
219	begin
220	Msg := SM_UnknownError;
221	Result := False;
222
223	if Length(FConnections) > 0 then
224	begin
225	for i := 0 to High(FConnections) do
226	begin
227	if FConnections[i].ConnectionID = ID then
228	begin
229	FConnections[i].Close;
230	RemoveConnection(i);
231	Msg := SM_OK;
232	Result := True;
233	Exit;
234	end;
235	end;
236	end;
237	end;
238
239	function TConnectionManager.CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean;
240	var
241	i: Integer;
242	begin
243	Msg := SM_UnknownError;
244	Result := False;
245
246	if Length(FConnections) > 0 then
247	begin
248	for i := 0 to High(FConnections) do
249	begin
250	if FConnections[i].FileName = FileName then
251	begin
252	FConnections[i].Close;
253	RemoveConnection(i);
254	Msg := SM_OK;
255	Result := True;
256	Exit;
257	end;
258	end;
259	end;
260	end;
261
262
263	initialization
264	ConManager := TConnectionManager.Create;
265	finalization
266	ConManager.Free;
267	end.