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TeeBI includes a built-in web server for serving data over HTTP, enabling remote access and web-based dashboards.

​
Basic Web Server

uses
  BI.Web.Server.Indy, BI.Web.Context;

type
  TWebServerForm = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    Server: THttpServer;
    procedure HandleRequest(const Context: TWebContext);
  end;

procedure TWebServerForm.FormCreate(Sender: TObject);
begin
  // Create HTTP server (uses Indy)
  Server := THttpServer.Create(Self);
  Server.Port := 15015;
  Server.OnCommandGet := HandleRequest;
  Server.Active := True;

  ShowMessage('Server started on port 15015');
end;

procedure TWebServerForm.HandleRequest(const Context: TWebContext);
begin
  // Handle HTTP GET request
  Context.Response.ContentText := 'Hello from TeeBI Web Server';
  Context.Response.ContentType := 'text/plain';
end;

procedure TWebServerForm.FormDestroy(Sender: TObject);
begin
  Server.Active := False;
  Server.Free;
end;

​
Serve Data as JSON

uses
  BI.DataItem, BI.Persist, BI.JSON, BI.Web.Context;

procedure HandleDataRequest(const Context: TWebContext);
var
  Data: TDataItem;
  JSON: String;
begin
  // Load data
  Data := TStore.Load('BISamples', 'Products');
  try
    // Convert to JSON
    JSON := TBIJSONExport.AsString(Data);
    
    // Return JSON response
    Context.Response.ContentText := JSON;
    Context.Response.ContentType := 'application/json';
  finally
    Data.Free;
  end;
end;

​
Query Parameters

uses
  BI.SQL, BI.Web.Context;

procedure HandleQueryRequest(const Context: TWebContext);
var
  Data, Result: TDataItem;
  Category, JSON: String;
begin
  // Get query parameter: /data?category=Electronics
  Category := Context.Request.Params.Values['category'];
  
  Data := TStore.Load('BISamples', 'Products');
  try
    // Apply filter if category provided
    if Category <> '' then
      Result := TBISQL.From(Data, 
        'ProductName, UnitPrice where Category = "' + Category + '"')
    else
      Result := Data;
    
    try
      JSON := TBIJSONExport.AsString(Result);
      Context.Response.ContentText := JSON;
      Context.Response.ContentType := 'application/json';
    finally
      if Result <> Data then
        Result.Free;
    end;
  finally
    Data.Free;
  end;
end;

​
URL Routing

uses
  System.SysUtils, BI.Web.Context;

procedure HandleRequest(const Context: TWebContext);
var
  Path: String;
begin
  Path := Context.Request.Document;
  
  if Path = '/products' then
    ServeProducts(Context)
  else if Path = '/customers' then
    ServeCustomers(Context)
  else if StartsText('/query/', Path) then
    HandleQuery(Context)
  else
  begin
    Context.Response.ContentText := 'Not Found';
    Context.Response.ResponseNo := 404;
  end;
end;

​
Binary Data Format

uses
  BI.Persist, System.Classes;

// Serve data in TeeBI binary format (faster, compressed)
procedure ServeBinaryData(const Context: TWebContext);
var
  Data: TDataItem;
  Stream: TMemoryStream;
begin
  Data := TStore.Load('BISamples', 'Products');
  try
    Stream := TMemoryStream.Create;
    try
      // Save to binary stream
      TDataItemPersistence.SaveToStream(Data, Stream);
      
      Stream.Position := 0;
      Context.Response.ContentStream := Stream;
      Context.Response.ContentType := 'application/octet-stream';
    except
      Stream.Free;
      raise;
    end;
  finally
    Data.Free;
  end;
end;

​
CORS Support

uses BI.Web.Context;

// Enable Cross-Origin Resource Sharing
procedure EnableCORS(const Context: TWebContext);
begin
  with Context.Response.CustomHeaders do
  begin
    Add('Access-Control-Allow-Origin=*');
    Add('Access-Control-Allow-Methods=GET, POST, OPTIONS');
    Add('Access-Control-Allow-Headers=Content-Type');
  end;
end;

procedure HandleWithCORS(const Context: TWebContext);
begin
  EnableCORS(Context);
  
  if Context.Request.Method = 'OPTIONS' then
  begin
    // Preflight request
    Context.Response.ResponseNo := 200;
    Exit;
  end;
  
  // Handle actual request
  HandleDataRequest(Context);
end;

​
Complete Web Server Example

uses
  BI.DataItem, BI.Persist, BI.SQL, BI.JSON,
  BI.Web.Server.Indy, BI.Web.Context,
  System.SysUtils, System.Classes;

type
  TBIWebServer = class(TForm)
    MemoLog: TMemo;
    BtnStart: TButton;
    BtnStop: TButton;
    EditPort: TEdit;
    LabelStatus: TLabel;
    LabelConnections: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure BtnStartClick(Sender: TObject);
    procedure BtnStopClick(Sender: TObject);
  private
    Server: THttpServer;
    Data: TDataItem;
    
    procedure LoadData;
    procedure HandleRequest(const Context: TWebContext);
    procedure HandleConnect(const Context: TWebContext);
    procedure HandleDisconnect(const Context: TWebContext);
    procedure HandleException(const Context: TWebContext; const E: Exception);
    procedure UpdateStatus;
    
    procedure ServeProductList(const Context: TWebContext);
    procedure ServeProductQuery(const Context: TWebContext);
    procedure ServeStatistics(const Context: TWebContext);
  end;

procedure TBIWebServer.FormCreate(Sender: TObject);
begin
  EditPort.Text := '15015';
  LoadData;
end;

procedure TBIWebServer.LoadData;
begin
  Data := TStore.Load('BISamples', 'Products');
  MemoLog.Lines.Add('Data loaded: ' + IntToStr(Data.Count) + ' products');
end;

procedure TBIWebServer.BtnStartClick(Sender: TObject);
begin
  if Server <> nil then Exit;
  
  try
    Server := THttpServer.Create(Self);
    Server.Port := StrToInt(EditPort.Text);
    Server.OnCommandGet := HandleRequest;
    Server.OnConnect := HandleConnect;
    Server.OnDisconnect := HandleDisconnect;
    Server.OnException := HandleException;
    Server.Active := True;
    
    UpdateStatus;
    MemoLog.Lines.Add('Server started on port ' + EditPort.Text);
    MemoLog.Lines.Add('Try: http://localhost:' + EditPort.Text + '/products');
  except
    on E: Exception do
    begin
      MemoLog.Lines.Add('Error starting server: ' + E.Message);
      Server.Free;
      Server := nil;
    end;
  end;
end;

procedure TBIWebServer.BtnStopClick(Sender: TObject);
begin
  if Server = nil then Exit;
  
  Server.Active := False;
  Server.Free;
  Server := nil;
  
  UpdateStatus;
  MemoLog.Lines.Add('Server stopped');
end;

procedure TBIWebServer.HandleRequest(const Context: TWebContext);
var
  Path: String;
begin
  Path := Context.Request.Document;
  
  MemoLog.Lines.Add('Request: ' + Path);
  
  // Enable CORS
  with Context.Response.CustomHeaders do
  begin
    Add('Access-Control-Allow-Origin=*');
    Add('Access-Control-Allow-Methods=GET');
  end;
  
  // Route to handlers
  if Path = '/products' then
    ServeProductList(Context)
  else if StartsText('/query', Path) then
    ServeProductQuery(Context)
  else if Path = '/stats' then
    ServeStatistics(Context)
  else
  begin
    Context.Response.ContentText := 
      '{"error": "Not Found", "path": "' + Path + '"}';
    Context.Response.ContentType := 'application/json';
    Context.Response.ResponseNo := 404;
  end;
end;

procedure TBIWebServer.ServeProductList(const Context: TWebContext);
var
  JSON: String;
begin
  JSON := TBIJSONExport.AsString(Data);
  Context.Response.ContentText := JSON;
  Context.Response.ContentType := 'application/json';
end;

procedure TBIWebServer.ServeProductQuery(const Context: TWebContext);
var
  Category, SQL, JSON: String;
  Result: TDataItem;
begin
  // GET /query?category=Electronics
  Category := Context.Request.Params.Values['category'];
  
  if Category <> '' then
    SQL := 'ProductName, UnitPrice, Stock where Category = "' + Category + '"'
  else
    SQL := 'ProductName, UnitPrice, Stock';
  
  Result := TBISQL.From(Data, SQL);
  try
    JSON := TBIJSONExport.AsString(Result);
    Context.Response.ContentText := JSON;
    Context.Response.ContentType := 'application/json';
  finally
    Result.Free;
  end;
end;

procedure TBIWebServer.ServeStatistics(const Context: TWebContext);
var
  Result: TDataItem;
  JSON: String;
begin
  // Return aggregated statistics
  Result := TBISQL.From(Data,
    'Category, count(*) as Count, sum(Stock) as TotalStock, ' +
    'avg(UnitPrice) as AvgPrice group by Category');
  try
    JSON := TBIJSONExport.AsString(Result);
    Context.Response.ContentText := JSON;
    Context.Response.ContentType := 'application/json';
  finally
    Result.Free;
  end;
end;

procedure TBIWebServer.HandleConnect(const Context: TWebContext);
begin
  UpdateStatus;
end;

procedure TBIWebServer.HandleDisconnect(const Context: TWebContext);
begin
  UpdateStatus;
end;

procedure TBIWebServer.HandleException(const Context: TWebContext; 
  const E: Exception);
begin
  MemoLog.Lines.Add('Exception: ' + E.Message);
  Context.Response.ContentText := 
    '{"error": "' + E.Message + '"}';
  Context.Response.ContentType := 'application/json';
  Context.Response.ResponseNo := 500;
end;

procedure TBIWebServer.UpdateStatus;
begin
  if Server <> nil then
  begin
    LabelStatus.Caption := 'Running';
    LabelConnections.Caption := 'Connections: ' + 
      IntToStr(Server.ContextsCount);
    BtnStart.Enabled := False;
    BtnStop.Enabled := True;
  end
  else
  begin
    LabelStatus.Caption := 'Stopped';
    LabelConnections.Caption := 'Connections: 0';
    BtnStart.Enabled := True;
    BtnStop.Enabled := False;
  end;
end;

procedure TBIWebServer.FormDestroy(Sender: TObject);
begin
  if Server <> nil then
  begin
    Server.Active := False;
    Server.Free;
  end;
  Data.Free;
end;

​
Client-Side Access

​
JavaScript Client

// Fetch data from TeeBI server
async function fetchProducts() {
  const response = await fetch('http://localhost:15015/products');
  const data = await response.json();
  console.log(data);
}

// Query with parameters
async function queryByCategory(category) {
  const response = await fetch(
    `http://localhost:15015/query?category=${category}`
  );
  const data = await response.json();
  return data;
}

// Get statistics
async function getStats() {
  const response = await fetch('http://localhost:15015/stats');
  const data = await response.json();
  return data;
}

​
Delphi Client

uses
  BI.DataSource, BI.JSON;

// Load data from remote server
var Data: TDataItem;
begin
  Data := TBIURLSource.From('http://server:15015/products');
  try
    BIGrid1.Data := Data;
  finally
    // Data owned by grid
  end;
end;

​
Performance Tips

Binary Format

Use TeeBI binary format for 10x faster transfers than JSON

Compression

Enable compression for large responses:
Context.Response.Compress := True;

Caching

Cache frequently accessed data in memory

Connection Pooling

Reuse data connections across requests

​
Security Considerations

The basic web server is for internal/development use. For production:
  • Implement authentication (JWT, OAuth)
  • Use HTTPS/TLS encryption
  • Validate and sanitize all inputs
  • Implement rate limiting
  • Use a reverse proxy (nginx, Apache)

​
See Also

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