Pascal (Lazarus/Delphi)
Pascal (Lazarus/Delphi)
Conversation with Streaming Responses
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Demonstrates an AI conversation with receiving streaming responses.Chilkat Pascal (Lazarus/Delphi) Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.Ai,
Chilkat.StringBuilder;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
ai: TAi;
systemMsg: string;
developerMsg: string;
conversationName: string;
sbEventName: TStringBuilder;
sbDelta: TStringBuilder;
sbFullResponse: TStringBuilder;
finished: Boolean;
abortFlag: Boolean;
maxWaitMs: Integer;
result: Integer;
result: Integer;
begin
success := False;
// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
ai := TAi.Create;
// The provider can be "openai", "google", "claude", "deepseek", "xai", or "perplexity".
// Support for additional providers will be added in future versions of Chilkat.
ai.Provider := 'google';
// Use your provider's API key.
ai.ApiKey := 'MY_API_KEY';
// Choose a model.
ai.Model := 'gemini-2.5-flash';
// Indicate streaming mode is to be used.
ai.Streaming := True;
// Create a new conversation to be maintained locally in memory.
// If the conversation is the first to be created, it is also automatically selected.
systemMsg := 'You are a creative storyteller';
developerMsg := '';
conversationName := 'test_conversation';
ai.NewConvo(conversationName,systemMsg,developerMsg);
// Add a text input.
ai.InputAddText('Write a detailed story about a turtle who decides to run a bakery. Describe the setting, the kinds of pastries, how the turtle feels, and include at least three paragraphs.');
// Ask the AI for text output.
success := ai.Ask('text');
if (success = False) then
begin
WriteLn(ai.LastErrorText);
Exit;
end;
sbEventName := TStringBuilder.Create;
sbDelta := TStringBuilder.Create;
sbFullResponse := TStringBuilder.Create;
finished := False;
abortFlag := False;
maxWaitMs := 5000;
while not finished do
begin
result := ai.PollAi(abortFlag);
if (result = 1) then
begin
// We have output waiting. It should be instantly available. The maxWaitMs is just-in-case.
success := ai.NextAiEvent(maxWaitMs,sbEventName,sbDelta);
if (success = False) then
begin
WriteLn(ai.LastErrorText);
Exit;
end;
// Some AI providers send many "empty" events. Just ignore them.
if (not sbEventName.ContentsEqual('empty',True)) then
begin
// The delta contains the new output. This could be emitted to a display or the terminal
// as real-time output.
if (sbEventName.ContentsEqual('delta',True)) then
begin
// This example will emit each delta to its own line.
WriteLn(sbDelta.GetAsString());
// Accumulate the delta's so we can show the full response later.
sbFullResponse.AppendSb(sbDelta);
end
else
begin
// A streaming AI response is always terminated by a single "null_terminator" event.
finished := sbEventName.ContentsEqual('null_terminator',True);
end;
end;
end
else
begin
if (result = 0) then
begin
// Nothing is immediately available. Sleep for 1/10 of a second before polling again.
ai.SleepMs(100);
end
else
begin
// Something failed..
WriteLn(ai.LastErrorText);
finished := True;
end;
end;
end;
// -------------------------------------------------------------
// The response is in markdown format.
// Also see Markdown to HTML Conversion Examples.
// -------------------------------------------------------------
// Show the accumulated (full) response.
WriteLn('----');
WriteLn(sbFullResponse.GetAsString());
WriteLn('----');
// ----------------------------------------------------------------------------------------------------------
// For the 2nd request in this conversation, ask for a shorter version of the story.
ai.InputAddText('Rewrite the story, but this time make it shorter, about one third as long.');
success := ai.Ask('text');
if (success = False) then
begin
WriteLn(ai.LastErrorText);
Exit;
end;
sbFullResponse.Clear();
finished := False;
while not finished do
begin
result := ai.PollAi(abortFlag);
if (result = 1) then
begin
// We have output waiting. It should be instantly available. The maxWaitMs is just-in-case.
success := ai.NextAiEvent(maxWaitMs,sbEventName,sbDelta);
if (success = False) then
begin
WriteLn(ai.LastErrorText);
Exit;
end;
// Some AI providers send many "empty" events. Just ignore them.
if (not sbEventName.ContentsEqual('empty',True)) then
begin
// The delta contains the new output. This could be emitted to a display or the terminal
// as real-time output.
if (sbEventName.ContentsEqual('delta',True)) then
begin
// This example will emit each delta to its own line.
WriteLn(sbDelta.GetAsString());
// Accumulate the delta's so we can show the full response later.
sbFullResponse.AppendSb(sbDelta);
end
else
begin
// A streaming AI response is always terminated by a single "null_terminator" event.
finished := sbEventName.ContentsEqual('null_terminator',True);
end;
end;
end
else
begin
if (result = 0) then
begin
// Nothing is immediately available. Sleep for 1/10 of a second before polling again.
ai.SleepMs(100);
end
else
begin
// Something failed..
WriteLn(ai.LastErrorText);
finished := True;
end;
end;
end;
WriteLn('----');
WriteLn(sbFullResponse.GetAsString());
ai.Free;
sbEventName.Free;
sbDelta.Free;
sbFullResponse.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.