delphi webbrowser: how to prevent or hide that javascript error? - delphi

I am running TEmbeddedwb and I got a javascript timeout error while navigating on that TEmbeddedwb .
(I do not have this error while running in my internet explorer !)
The browser asks me if I want to stop the execution of the script.
I put the TEmbeddedwb propertioes to
silent = true
dialogoBox.disableAll = true
But I still have this popup comming out !
1) why do I have this error (tested on 2pcs) while there is no error while navigating on Internet explorer
2) how to disable / hide this popup ?
regards
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, OleCtrls, SHDocVw_EWB, EwbCore, EmbeddedWB;
type
TForm1 = class(TForm)
iemain: TEmbeddedWB;
procedure iemainScriptError(Sender: TObject; ErrorLine, ErrorCharacter,
ErrorCode, ErrorMessage, ErrorUrl: String;
var ScriptErrorAction: TScriptErrorAction);
procedure FormCreate(Sender: TObject);
private
{ Déclarations privées }
public
{ Déclarations publiques }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.iemainScriptError(Sender: TObject; ErrorLine,
ErrorCharacter, ErrorCode, ErrorMessage, ErrorUrl: String;
var ScriptErrorAction: TScriptErrorAction);
begin
MessageDlg('hello', mtWarning, [mbOK], 0);
if ErrorCode='123' then ScriptErrorAction := eaContinue;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
iemain.Navigate('http://www.expedia.fr/Hotels');
end;
end.

How to handle JavaScript error in TEmbeddedWB ?
Write a handler for the OnScriptError event and return one of the available TScriptErrorAction values in the ScriptErrorAction output parameter. To ignore the script error and continue use e.g.:
procedure TForm1.EmbeddedWB1ScriptError(Sender: TObject; ErrorLine,
ErrorCharacter, ErrorCode, ErrorMessage, ErrorUrl: string;
var ScriptErrorAction: TScriptErrorAction);
begin
if ErrorCode = 123 then
ScriptErrorAction := eaContinue;
end;

Related

Delphi 6 indy connection hanging

I am having small issue. After I make a connection between the server and client. I would close the client, and then the server, but the server hangs and sends me a "program has crashed" I think the problem I am having is that the server doesn't recognize a client has disconnected, and still thinks the client is active. Here is the source code:
client:
unit client;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ScktComp, Winsock, IdBaseComponent, IdComponent,
IdTCPConnection, IdTCPClient;
type
TForm1 = class(TForm)
IdTCPClient1: TIdTCPClient;
procedure FormCreate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
function GetIpFromDns(HostName: string): string;
type
tAddr = array[0..100] of PInAddr;
pAddr = ^tAddr;
var
I: Integer;
WSA: TWSAData;
PHE: PHostEnt;
P: pAddr;
begin
Result := HostName;
WSAStartUp($101, WSA);
try
PHE := GetHostByName(pChar(HostName));
if (PHE <> nil) then
begin
P := pAddr(PHE^.h_addr_list);
I := 0;
while (P^[i] <> nil) do
begin
Result := (inet_nToa(P^[i]^));
Inc(I);
end;
end;
except
end;
WSACleanUp;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
IdTCPClient1.Host := GetIpFromDns('example.no-ip.org');
IdTCPClient1.Port := 9000;
IdTCPClient1.Connect;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
if IdTCPclient1.Connected = True then
IdTCPClient1.Disconnect
else
end;
end.
Server:
unit server;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ScktComp, IdBaseComponent, IdComponent, IdTCPServer;
type
TForm1 = class(TForm)
IdTCPServer1: TIdTCPServer;
procedure IdTCPServer1Connect(AThread: TIdPeerThread);
procedure IdTCPServer1Disconnect(AThread: TIdPeerThread);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.IdTCPServer1Connect(AThread: TIdPeerThread);
begin
showmessage('client connected');
end;
procedure TForm1.IdTCPServer1Disconnect(AThread: TIdPeerThread);
begin
showmessage('client disconnected');
end;
end.
it may not look like I set up a listening port for indy, but I did in the object inspector page. For some reason if I put IdTCPServer.DefaultPort and Active in the form create it throws more errors.
I also tried IdTCPClient1.DisconnectSocket but no luck there either.
Do I need to create something on the server side to check the connections periodically? if so, what would be best way to do that?

TCP Client not receiving responses back from RTSP server

In Delphi XE2, I'm using the TTCPClient component to communicate with an RTSP server. After trial and error not getting a response back from the server, I switched the project to send HTTP requests via port 80 (instead of 554 for RTSP) and tried to send a request to a website (www.google.com specifically). I'm still not getting any response.
I have a TTCPClient component on the main form (Form1) called Client, a TMemo control called Log, a TEdit control called txtHost, and a TBitBtn control. Here's the relevant parts of the code:
Connecting to Server
procedure TForm1.BitBtn1Click(Sender: TObject);
begin
if Client.Active then Client.Disconnect;
Client.RemoteHost:= txtHost.Text;
Client.RemotePort:= '80'; // '554';
Client.Connect;
end;
OnConnect Event Handler (HTTP)
procedure TForm1.ClientConnect(Sender: TObject);
var
S: String;
begin
Client.Sendln('GET / HTTP/1.0');
Client.SendLn('');
end;
OnConnect Event Handler (RTSP)
procedure TForm1.ClientConnect(Sender: TObject);
var
S: String;
begin
Client.SendLn('OPTIONS * RTSP/1.0');
Client.SendLn('CSeq:0');
Client.SendLn('');
end;
OnReceive Event Handler
procedure TForm1.ClientReceive(Sender: TObject; Buf: PAnsiChar;
var DataLen: Integer);
var
S, R: String;
begin
S:= Client.Receiveln;
while S <> '' do begin
R:= R+ S;
S:= Client.Receiveln;
end;
Log.Lines.Append('> RECEIVED ' + R);
end;
OnError Event Handler
procedure TForm1.ClientError(Sender: TObject; SocketError: Integer);
begin
Log.Lines.Append('> ERROR '+IntToStr(SocketError));
end;
The OnReceive event is never called, nothing is coming back from any Server I'm connecting to.
What am I doing wrong here?
References
These are some links which I'm referencing to:
http://effbot.org/zone/socket-intro.htm
http://www.ietf.org/rfc/rfc2326.txt
http://folk.uio.no/meccano/reflector/smallclient.html
http://www.samsungdforum.com/upload_files/files/guide/data/html/html_3/reference/rtsp_specification.html
The camera I'm working with is Grandstream GXV3601LL
UPDATE
I've concluded that the issue is with the RTSP server, and have asked a question on the forums on Grandstream's website. The code does work with other server connections.
This works for me, it depends if you are in blocking mode or not:
unit Unit11;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Sockets, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, StdCtrls;
type
TForm1 = class(TForm)
IdTCPClient1: TIdTCPClient;
TcpClient1: TTcpClient;
Memo1: TMemo;
procedure TcpClient1Connect(Sender: TObject);
procedure TcpClient1Receive(Sender: TObject; Buf: PAnsiChar; var DataLen: Integer);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
begin
TcpClient1.BlockMode := bmBlocking;
TcpClient1.RemoteHost := 'www.google.com';
TcpClient1.RemotePort := '80';
TcpClient1.Connect;
end;
procedure TForm1.TcpClient1Connect(Sender: TObject);
var s : string;
begin
memo1.Lines.Add('connected');
TcpClient1.Sendln('GET /');
s := TcpClient1.Receiveln;
memo1.Lines.Add(S);
end;
end.
EDIT
here is a real world example with a RTSP server (youtube in this case)
I used Indy IdTcpClient
unit Unit11;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Sockets, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, StdCtrls;
type
TForm1 = class(TForm)
Memo1: TMemo;
Client: TIdTCPClient;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
var s : string;
begin
Client.Host := 'v5.cache6.c.youtube.com';
Client.Port := 554;
Client.Connect;
Client.IOHandler.Writeln('OPTIONS * RTSP/1.0');
Client.IOHandler.Writeln('CSeq: 1');
Client.IOHandler.Writeln('');
s := Client.IOHandler.ReadLn;
Memo1.Lines.Add(s);
s := Client.IOHandler.ReadLn;
Memo1.Lines.Add(s);
end;
end.
The reason the OnReceive event is not called is because TTCPClient is NOT an asynchronous component, like you are trying to treat it. The OnReceive event DOES NOT work the same way as the old TClientSocket.OnRead event. The OnReceive event is called inside of the ReceiveBuf() method only (ReceiveLn() calls ReceiveBuf() internally). The data that is passed to the OnReceive event is the same data that the ReceiveBuf() method returns on output. You have a catch-22 situation - you are waiting for the OnReceive event before calling ReceiveLn(), but OnReceive will not be triggered until you call ReceiveLn() first. If you want to use TTCPClient asynchronously, you will have to call its ReceiveLn() method periodically, either in a timer or worker thread, NOT inside the OnReceive event.
The TTCPClient component is part of the old CLX framework for Kylix. It is not part of the VCL, or even FireMonkey, and should not be used anymore. Either use the old TClientSocket component (which is deprecated but still available), or change to another component library, such as Indy.

RemObjects Hydra Plugin Can't Handle WM_DEVICECHANGE Windows Messages Directly

I Creating a Hydra Host Application and a Hydra Plugin. I put a Procedure for Handling a Windows Message in Plugin; but in this case we can't handle this windows message. for solving this problem we can handle It in Host App and then we must talk with pluging via passing an Interface.
In this case I want to find a direct way for handle windows messages in Hydra Plugin. Please help me for solving this problem.
Update 1 for this Question:
this is a simple code for testing:
Plugin Side:
unit VisualPlugin;
interface
uses
{ vcl: } Windows, Messages, SysUtils, Variants, Classes, Graphics,
Controls, Forms, Dialogs, StdCtrls,
{ Hydra: } uHYVisualPlugin, uHYIntf;
type
TVisualPlugin1 = class(THYVisualPlugin)
private
procedure WMDEVICECHANGE(var Msg: TMessage); message WM_DEVICECHANGE;
end;
implementation
uses
{ Hydra: } uHYPluginFactories;
{$R *.dfm}
procedure Create_VisualPlugin1(out anInstance: IInterface);
begin
anInstance := TVisualPlugin1.Create(NIL);
end;
resourcestring
sDescription = '';
const
sRequiredPrivilege = '';
sUserData = '';
{ TVisualPlugin1 }
procedure TVisualPlugin1.WMDEVICECHANGE(var Msg: TMessage);
begin
// ===================================
// This Line Of Code Can't Be Run!!!!!!
ShowMessage('USB Changed');
// ===================================
end;
initialization
THYPluginFactory.Create(HInstance, 'VisualPlugin1', Create_VisualPlugin1,
TVisualPlugin1, 1, 0, sRequiredPrivilege, sDescription, sUserData);
end.
PluginController in Plugin Side:
unit hcPluginController;
interface
uses
{vcl:} SysUtils, Classes,
{Hydra:} uHYModuleController, uHYIntf, uHYCrossPlatformInterfaces;
type
TPluginController = class(THYModuleController)
private
public
end;
var
PluginController : TPluginController;
implementation
uses
{Hydra:} uHYRes;
{$R *.dfm}
procedure HYGetCrossPlatformModule(out result: IHYCrossPlatformModule); stdcall;
begin
result := PluginController as IHYCrossPlatformModule;
end;
function HYGetModuleController : THYModuleController;
begin
result := PluginController;
end;
exports
HYGetCrossPlatformModule,
HYGetModuleController name name_HYGetModuleController;
resourcestring
sDescription = '';
const
sRequiredPrivilege = '';
initialization
PluginController := TPluginController.Create('Plugin.Library', 1, 0, sRequiredPrivilege, sDescription);
finalization
FreeAndNil(PluginController);
end.
Host Application Side:
unit fMain;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, uHYModuleManager, uHYIntf, ExtCtrls, StdCtrls;
type
TMainForm = class(TForm)
HYModuleManager1: THYModuleManager;
Panel1: TPanel;
btnLoadPlugin: TButton;
procedure btnLoadPluginClick(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
{ Public declarations }
end;
var
MainForm: TMainForm;
implementation
{$R *.dfm}
var
AppDir: string;
fPlugin: IHYVisualPlugin;
const
PluginDll = 'Plugin.dll';
PluginName = 'VisualPlugin1';
procedure TMainForm.btnLoadPluginClick(Sender: TObject);
begin
if HYModuleManager1.FindModule(AppDir + PluginDll) = nil then
HYModuleManager1.LoadModule(AppDir + PluginDll);
HYModuleManager1.CreateVisualPlugin(PluginName, fPlugin, Panel1);
end;
procedure TMainForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
HYModuleManager1.ReleaseInstance(fPlugin);
HYModuleManager1.UnloadModules;
end;
procedure TMainForm.FormCreate(Sender: TObject);
begin
AppDir := ExtractFilePath(Application.ExeName);
end;
end.
Not sure about the real cause of the problem, but you can use RegisterDeviceNotification function to achieve same result:
type
DEV_BROADCAST_DEVINTERFACE = record
dbcc_size: DWORD;
dbcc_devicetype: DWORD;
dbcc_reserved: DWORD;
dbcc_classguid: TGUID;
dbcc_name: short;
end;
const
DEVICE_NOTIFY_ALL_INTERFACE_CLASSES = $4;
DBT_DEVTYP_DEVICEINTERFACE = $5;
function RegisterNotification(Handle: THandle): HDEVNOTIFY;
var
Filter: DEV_BROADCAST_DEVINTERFACE;
begin
ZeroMemory(#Filter, SizeOf(DEV_BROADCAST_DEVINTERFACE));
Filter.dbcc_size := SizeOf(DEV_BROADCAST_DEVINTERFACE);
Filter.dbcc_devicetype := DBT_DEVTYP_DEVICEINTERFACE;
Filter.dbcc_reserved := 0;
Filter.dbcc_name := 0;
Result := RegisterDeviceNotification(Handle, #Filter, DEVICE_NOTIFY_WINDOW_HANDLE or DEVICE_NOTIFY_ALL_INTERFACE_CLASSES);
end;
Now inside plugin you need something like this:
TVisualPlugin = class(THYVisualPlugin)
protected
NofitifyHandle: HDEVNOTIFY;
procedure WMDEVICECHANGE(var Msg: TMessage); message WM_DEVICECHANGE;
procedure CreateWnd; override;
procedure DestroyWindowHandle; override;
end;
procedure TVisualPlugin.CreateWnd;
begin
inherited;
if HandleAllocated then
NofitifyHandle := RegisterNotification(Self.Handle);
end;
procedure TVisualPlugin.DestroyWindowHandle;
begin
if Assigned(NofitifyHandle) then begin
UnregisterDeviceNotification(NofitifyHandle);
NofitifyHandle := nil;
end;
inherited;
end;
procedure TVisualPlugin.WMDEVICECHANGE(var Msg: TMessage);
begin
ShowMessage('USB Changed');
end;

Delphi throbber

What is the best solution to show that the application is doing something?
I tried showing a progress indicator, but it did not work.
UPDATE: -------------
A progress bar works fine, but isn't what I want.
I want to show a throbber, like what Web browsers use, so as long as something is being updated it keeps turning.
Cursor can also be in crHourGlass mode.
Try this:
AnimateUnit
unit AnimateUnit;
interface
uses
Windows, Classes;
type
TFrameProc = procedure(const theFrame: ShortInt) of object;
TFrameThread = class(TThread)
private
{ Private declarations }
FFrameProc: TFrameProc;
FFrameValue: ShortInt;
procedure SynchedFrame();
protected
{ Protected declarations }
procedure Frame(const theFrame: ShortInt); virtual;
public
{ Public declarations }
constructor Create(theFrameProc: TFrameProc; CreateSuspended: Boolean = False); reintroduce; virtual;
end;
TAnimateThread = class(TFrameThread)
private
{ Private declarations }
protected
{ Protected declarations }
procedure Execute(); override;
public
{ Public declarations }
end;
var
AnimateThread: TAnimateThread;
implementation
{ TFrameThread }
constructor TFrameThread.Create(theFrameProc: TFrameProc; CreateSuspended: Boolean = False);
begin
inherited Create(CreateSuspended);
FreeOnTerminate := True;
FFrameProc := theFrameProc;
end;
procedure TFrameThread.SynchedFrame();
begin
if Assigned(FFrameProc) then FFrameProc(FFrameValue);
end;
procedure TFrameThread.Frame(const theFrame: ShortInt);
begin
FFrameValue := theFrame;
try
Sleep(0);
finally
Synchronize(SynchedFrame);
end;
end;
{ TAnimateThread }
procedure TAnimateThread.Execute();
var
I: ShortInt;
begin
while (not Self.Terminated) do
begin
Frame(0);
for I := 1 to 8 do
begin
if (not Self.Terminated) then
begin
Sleep(120);
Frame(I);
end;
end;
Frame(0);
end;
end;
end.
Unit1
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls, ImgList;
type
TForm1 = class(TForm)
ImageList1: TImageList;
Image1: TImage;
Button1: TButton;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
procedure UpdateFrame(const theFrame: ShortInt);
end;
var
Form1: TForm1;
implementation
uses
AnimateUnit;
{$R *.DFM}
procedure TForm1.UpdateFrame(const theFrame: ShortInt);
begin
Image1.Picture.Bitmap.Handle := 0;
try
ImageList1.GetBitmap(theFrame, Image1.Picture.Bitmap);
finally
Image1.Update();
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
AnimateThread := TAnimateThread.Create(UpdateFrame);
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
AnimateThread.Terminate();
end;
end.
The Images
You are probably running your time consuming task in the main thread.
One option is to move it to a background thread which will allow your message queue to be serviced. You need it to be serviced in order for your progress bar, and indeed any UI, to work.
Answer to the updated question:
generate an animated gif e.g. here
add a GIF library to your environment (JEDI JVCL+JCL)
insert a TImage and load the generated gif
make it visible if you need it
A indicator is OK. You have to call Application.ProcessMessages after changing it.
"What is the best solution to show that that application is doing something?" - set mouse cursor to crHourGlass? or to create another form/frame/etc which attentions the user that the application is 'doing' something, and he needs to wait.
From your lengthy task, you can occasionally update a visual indicator, like a progress bar or anything else. However, you need to redraw the changes immediately by calling Update on the control that provides the feedback.
Don't use Application.ProcessMessages as this will introduce possible reentrancy issues.

NetUserGetLocalGroups - how to call it?

I am using Delphi 2010, latest version (from repository) of JEDI WinAPI and Windows Security Code Library (WSCL).
I don't know how to call the NetUserSetGroups function. The way I am doing it, it is throwing an exception:
Access violation at address 5B8760BE
in module 'netapi32.dll'. Write of
address 00000000.
Following is my code:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, JwaWindows, JwsclSid;
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
var
NetApiStatus: NET_API_STATUS;
dwEntriesRead, dwEntriesTotal: PDWORD;
lgi01: LOCALGROUP_USERS_INFO_0;
username: PChar;
begin
username := 'Elise';
NetApiStatus := NetUserGetLocalGroups(nil, PChar(username), 0, LG_INCLUDE_INDIRECT, PByte(lgi01),
MAX_PREFERRED_LENGTH, dwEntriesRead, dwEntriesTotal);
if NetApiStatus = NERR_SUCCESS then
showmessage('Total groups user belongs to: ' + IntTostr(dwEntriesTotal^));
end;
end.
Would appreciate if someone could kindly show me how I can call this function?
Thanks in advance.
This code works fine for me:
type
LocalGroupUsersInfo0Array = array[0..ANYSIZE_ARRAY-1] of LOCALGROUP_USERS_INFO_0;
PLocalGroupUsersInfo0Array = ^LocalGroupUsersInfo0Array;
procedure TForm3.Button3Click(Sender: TObject);
var
nas: NET_API_STATUS;
PLGUIA: PLocalGroupUsersInfo0Array;
Count: DWORD;
Total: DWORD;
i: Integer;
begin
PLGUIA := nil;
nas := NetUserGetLocalGroups(nil, PChar('rweijnen'), 0, LG_INCLUDE_INDIRECT,
PByte(PLGUIA), MAX_PREFERRED_LENGTH, #Count, #Total);
if (nas = NERR_Success) or (nas = ERROR_MORE_DATA) then
begin
for i := 0 to Count - 1 do
begin
Memo1.Lines.Add(Format('name=%s', [PLGUIA^[i].lgrui0_name]));
end;
if Assigned(PLGUIA) then
NetApiBufferFree(PLGUIA);
end;
end;

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