Merge pull request #1 from monde-sistemas/improvements

Improvements on Error Handling and Connect() usability

Author: RobertoSchneiders

README.md

@@ -29,6 +29,11 @@ All of them are shipped with this lib releases.
 
 Download the [last release](https://github.com/monde-sistemas/pusher-websocket-delphi/releases/latest) zip package and add it to your project. Make sure all the dependencies are on the same folder that your exe.
 
+Register the DLL using RegAsm:
+```
+%windir%\Microsoft.NET\Framework\v4.0.30319\regasm.exe /codebase PusherClientNative.dll /tlb:PusherClientNative.tlb
+```
+
 Add `PusherClient` to your unit uses clause.
 
 ```
@@ -56,14 +61,14 @@ end;
 
 SSL is enabled by default. You can disable it by passing a empty option list `[]` to the `Connect` method:
 ```
-PusherClient.Connect('your_pusher_key', []);
+PusherClient.Connect('your_pusher_key', '', []);
 ```
 
 ### Custom Host Address
 
 It is possible to use a custom host address:
 ```
-PusherClient.Connect('your_pusher_key', [], 'localhost');
+PusherClient.Connect('your_pusher_key', 'localhost');
 ```
 The [default value](https://github.com/pusher-community/pusher-websocket-dotnet/blob/master/PusherClient/Pusher.cs#L43) is `ws.pusherapp.com` which is the pusher.com endpoint, but you can also use it with a [poxa](https://github.com/edgurgel/poxa) server hosted in your own server.
 

delphi/PusherClient/PusherClient.pas

@@ -28,9 +28,8 @@   TPusherClient = class
     procedure Log(Message: string);
     procedure ConnectionStateChange(Message: string);
   public
-    class function GetInstance(): TPusherClient;
-    procedure Connect(Key: string; Options: TConnectionOptions = [coUseSSL];
-      CustomHost: string = '');
+    class function Instance(): TPusherClient;
+    procedure Connect(Key: string; CustomHost: string = ''; Options: TConnectionOptions = [coUseSSL]);
     procedure Disconnect();
     procedure Subscribe(Channel, EventName: String; Callback: TCallbackProcedure);
     property OnError: TCallbackProcedure read FOnError write FOnError;
@@ -47,20 +46,20 @@ implementation
 
 procedure OnLogStdCall(Message: pchar); stdcall;
 begin
-  TPusherClient.GetInstance.Log(StrPas(Message));
+  TPusherClient.Instance.Log(StrPas(Message));
 end;
 
 procedure OnErrorStdCall(message: pchar); stdcall;
 begin
-  TPusherClient.GetInstance.Error(StrPas(Message));
+  TPusherClient.Instance.Error(StrPas(Message));
 end;
 
 procedure OnSubscribeEventStdCall(Channel: pchar; EventName: pchar; Message: pchar); stdcall;
 var
   ErrorMessage: string;
 begin
   try
-    TPusherClient.GetInstance.FSubscribed[StrPas(Channel)][StrPas(EventName)](StrPas(Message));
+    TPusherClient.Instance.FSubscribed[StrPas(Channel)][StrPas(EventName)](StrPas(Message));
   except
     on E:Exception do
     begin
@@ -69,18 +68,18 @@ procedure OnSubscribeEventStdCall(Channel: pchar; EventName: pchar; Message: pch
         + sLineBreak + '[Channel][Event]: Message: [%s][%s]: [%s]'
         + sLineBreak + 'Error: [%s]',
         [StrPas(Channel), StrPas(EventName), StrPas(Message), E.Message]);
-      TPusherClient.GetInstance.Error(ErrorMessage);
-      TPusherClient.GetInstance.Log(ErrorMessage);
+      TPusherClient.Instance.Error(ErrorMessage);
+      TPusherClient.Instance.Log(ErrorMessage);
     end;
   end;
 end;
 
 procedure OnConnectionStateChangeStdCall(message: pchar); stdcall;
 begin
-  TPusherClient.GetInstance.ConnectionStateChange(StrPas(Message));
+  TPusherClient.Instance.ConnectionStateChange(StrPas(Message));
 end;
 
-procedure TPusherClient.Connect(Key: string; Options: TConnectionOptions; CustomHost: string);
+procedure TPusherClient.Connect(Key, CustomHost: string; Options: TConnectionOptions);
 begin
   PusherClientNative.InitializePusherClient(Key, coUseSSL in Options, CustomHost);
 
@@ -111,7 +110,7 @@ procedure TPusherClient.Disconnect;
   PusherClientNative.Disconnect;
 end;
 
-class function TPusherClient.GetInstance: TPusherClient;
+class function TPusherClient.Instance: TPusherClient;
 begin
   if not Assigned(Self.FInstance) then
     self.FInstance := TPusherClient.Create;
@@ -120,20 +119,37 @@ class function TPusherClient.GetInstance: TPusherClient;
 
 procedure TPusherClient.ConnectionStateChange(Message: string);
 begin
-  if Assigned(TPusherClient.GetInstance.FOnConnectionStateChange) then
-    TPusherClient.GetInstance.FOnConnectionStateChange(Message);
+  try
+    if Assigned(FOnConnectionStateChange) then
+      FOnConnectionStateChange(Message);
+  except
+    on E:Exception do
+      Error('An error occurred while calling the event OnConnectionStateChange: ' + e.message)
+  end;
 end;
 
 procedure TPusherClient.Error(Message: string);
 begin
-  if Assigned(TPusherClient.GetInstance.FOnError) then
-    TPusherClient.GetInstance.FOnError(Message);
+  try
+    if Assigned(FOnError) then
+      FOnError(Message);
+  except
+    // This method cannot fail under any circumstances. It is called by the ComObj callback.
+    // if some of the others callbacks (OnLog, OnConnectionStateChange) fails they will call this
+    // method to try to inform the client application about the problem, but, if this method
+    // fails, there are nothing we can do.
+  end;
 end;
 
 procedure TPusherClient.Log(Message: string);
 begin
-  if Assigned(TPusherClient.GetInstance.FOnLog) then
-    TPusherClient.GetInstance.FOnLog(Message);
+  try
+    if Assigned(FOnLog) then
+      FOnLog(Message);
+  except
+    on E:Exception do
+      Error('An error occurred while calling the event OnLog: ' + e.message)
+  end;
 end;
 
 class procedure TPusherClient.ReleaseInstance;

delphi/example/example.pas

@@ -33,8 +33,6 @@   TPusherClientExampleForm = class(TForm)
     procedure ConnectionStatus(Status: string);
     procedure Connect;
     procedure Disconnect;
-  public
-    { Public declarations }
   end;
 
 var
@@ -73,11 +71,11 @@ procedure TPusherClientExampleForm.BtnSubscribeClick(Sender: TObject);
   if SubscribeList.Items.IndexOf(ListItem) = -1 then
     SubscribeList.Items.Add(EdtChannel.Text + ' | ' + EdtEvent.Text);
 
-   PusherClient.Subscribe(EdtChannel.Text, EdtEvent.Text,
-     procedure (Message: string)
-     begin
-       Log('[EVENT-MESSAGE]: ' + Message)
-     end)
+  PusherClient.Subscribe(EdtChannel.Text, EdtEvent.Text,
+    procedure (Message: string)
+    begin
+      Log('[EVENT-MESSAGE]: ' + Message)
+    end)
 end;
 
 procedure TPusherClientExampleForm.Connect;
@@ -88,7 +86,7 @@ procedure TPusherClientExampleForm.Connect;
   if ChkUseSSL.Checked then
     Options := [coUseSSL];
 
-  PusherClient.Connect(EdtKey.Text, Options, EdtHost.Text);
+  PusherClient.Connect(EdtKey.Text, EdtHost.Text, Options);
 end;
 
 procedure TPusherClientExampleForm.ConnectionStatus(Status: string);
@@ -115,7 +113,7 @@ procedure TPusherClientExampleForm.Error(Message: string);
 
 procedure TPusherClientExampleForm.InitializePusherClient;
 begin
-  PusherClient := TPusherClient.GetInstance;
+  PusherClient := TPusherClient.Instance;
   PusherClient.OnError := procedure(Message: string)
     begin
       Error('[ERROR]: ' + Message);

dotnet/PusherClientNative/register_dll.bat

@@ -0,0 +1 @@
+%windir%\Microsoft.NET\Framework\v4.0.30319\regasm.exe /codebase PusherClientNative.dll /tlb:PusherClientNative.tlb