An HttpResponse represents the headers and data to be returned to a client in response to an HTTP request.

This object has a number of properties for setting up the HTTP header of the response. When the header has been set up the methods from the IOSink can be used to write the actual body of the HTTP response. When one of the IOSink methods is used for the first time the request header is send. Calling any methods that will change the header after it is sent will throw an exception.

When writing string data through the IOSink the encoding used will be determined from the "charset" parameter of the "Content-Type" header.

HttpResponse response = ...
response.headers.contentType
    = new ContentType("application", "json", charset: "utf-8");
response.write(...);  // Strings written will be UTF-8 encoded.

If no charset is provided the default of ISO-8859-1 (Latin 1) will be used.

HttpResponse response = ...
response.headers.add(HttpHeaders.CONTENT_TYPE, "text/plain");
response.write(...);  // Strings written will be ISO-8859-1 encoded.

If an unsupported encoding is used an exception will be thrown if using one of the write methods taking a string.

abstract class HttpResponse implements IOSink {
 // TODO(ajohnsen): Add documentation of how to pipe a file to the response.
 /**
  * Gets and sets the content length of the response. If the size of
  * the response is not known in advance set the content length to
  * -1 - which is also the default if not set.
  */
 int contentLength;

 /**
  * Gets and sets the status code. Any integer value is accepted. For
  * the official HTTP status codes use the fields from
  * [HttpStatus]. If no status code is explicitly set the default
  * value [HttpStatus.OK] is used.
  */
 int statusCode;

 /**
  * Gets and sets the reason phrase. If no reason phrase is explicitly
  * set a default reason phrase is provided.
  */
 String reasonPhrase;

 /**
  * Gets and sets the persistent connection state. The initial value
  * of this property is the persistent connection state from the
  * request.
  */
 bool persistentConnection;

 /**
  * Returns the response headers.
  */
 HttpHeaders get headers;

 /**
  * Cookies to set in the client (in the 'set-cookie' header).
  */
 List<Cookie> get cookies;

 /**
  * Detaches the underlying socket from the HTTP server. When the
  * socket is detached the HTTP server will no longer perform any
  * operations on it.
  *
  * This is normally used when a HTTP upgrade request is received
  * and the communication should continue with a different protocol.
  */
 Future<Socket> detachSocket();

 /**
  * Gets information about the client connection. Returns [null] if the socket
  * is not available.
  */
 HttpConnectionInfo get connectionInfo;
}