(Delphi ActiveX) Azure Service Bus - Send Message to Topic

See more Azure Service Bus Examples

Example code showing how to send a message to an Azure Service Bus Topic.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rest: TChilkatRest;
bAutoReconnect: Integer;
success: Integer;
sbToken: TChilkatStringBuilder;
topicName: WideString;
sbRequestBody: TChilkatStringBuilder;
sbPath: TChilkatStringBuilder;
json: TChilkatJsonObject;
sbResponseBody: TChilkatStringBuilder;

begin
// Note: Requires Chilkat v9.5.0.65 or greater.

// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Make the initial connection.
// A single REST object, once connected, can be used for many Azure Service Bus REST API calls.
// The auto-reconnect indicates that if the already-established HTTPS connection is closed,
// then it will be automatically re-established as needed.
rest := TChilkatRest.Create(Self);
bAutoReconnect := 1;
success := rest.Connect('<yournamespace>.servicebus.windows.net',443,1,bAutoReconnect);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// ----------------------------------------------------------------------------------------------
// The code above this comment could be placed inside a function/subroutine within the application
// because the connection does not need to be made for every request.  Once the connection is made
// the app may send many requests..
// ----------------------------------------------------------------------------------------------

// Let's load a previously computed SAS token and use it.
// See Azure Shared Access Signature for an example to genenerate an Azure SAS token.
sbToken := TChilkatStringBuilder.Create(Self);
sbToken.LoadFile('qa_data/tokens/serviceBusSas.txt','utf-8');

// Tell the REST object to use the Azure Shared Access Signature for authorization.
sbToken.Prepend('SharedAccessSignature ');
rest.AddHeader('Authorization',sbToken.GetAsString());

// ----------------------------------------------------------------------------------------------

// The code for sending to a topic is identical to the code sending to a queue.
// The only difference is that a topic name (or topic path) is used instead of queue name/path.

// Send to a topic named "gilaMonster";
topicName := 'gilaMonster';

// The HTTP request body contains the content of the message sent to the topic.
sbRequestBody := TChilkatStringBuilder.Create(Self);
sbRequestBody.Append('Hello, I''m a gila monster!');

// Build the path..
sbPath := TChilkatStringBuilder.Create(Self);
sbPath.Append('/');
sbPath.Append(topicName);
sbPath.Append('/messages');

// Add timeout and api-version query parameters.
rest.AddQueryParam('timeout','20');
rest.AddQueryParam('api-version','2013-08');

// Standard brokered message properties are placed in a BrokerProperties HTTP header. 
// The broker properties must be serialized in JSON format. To specify a TimeToLive value of 3600 seconds 
// and to add a message label "M1" to the message..
json := TChilkatJsonObject.Create(Self);
json.AppendInt('TimeToLive',3600);
json.AppendString('Label','A123');
rest.AddHeader('BrokerProperties',json.Emit());

// To add custom properties, such as "Priority" and "Color"
rest.AddHeader('Priority','High');
rest.AddHeader('Color','pink');

sbResponseBody := TChilkatStringBuilder.Create(Self);
success := rest.FullRequestSb('POST',sbPath.GetAsString(),sbRequestBody.ControlInterface,sbResponseBody.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Response Status Code = ' + IntToStr(rest.ResponseStatusCode));

// Check for a success response.
if (rest.ResponseStatusCode <> 201) then
  begin
    Memo1.Lines.Add(rest.LastRequestStartLine);
    Memo1.Lines.Add(rest.LastRequestHeader);
    Memo1.Lines.Add(sbResponseBody.GetAsString());
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// If successful, the 201 response will have no response body.

Memo1.Lines.Add('Success.');
end;