HTTP Component

The HTTP control can be used to retrieve documents from the World Wide Web. (NOTE: The following is a very short description. For more information, please consult the help files that come with the respective package.)

The HTTP control implements a standard HTTP Version 1.0 client through a simple plug-and-play interface.

The control contains a number of properties that map directly to HTTP request headers. Files are received through events: Transfer for contents, and Header for HTTP headers. The StartTransfer and EndTransfer events are fired at the beginning and end of transmission.

The URL property specifies the document to receive. To receive the document set the Action property to 'Get'. Data can be POST-ed to the HTTP server by assigning it to the PostData property and then setting the Action property to 'Post'.

The HTTP control supports the HTTP Basic authentication scheme through the User and Password properties. Other authentication schemes can be implemented by using the Authorization property.

This control requires a Winsock 1.1 compliant TCP/IP stack. This means that the Winsock stack installed in the system must have a version of at least 1.1. In particular, Windows 95, 98, and NT machines with Winsock 2.0 are fully supported.

PROPERTIES

Accept. A list of acceptable MIME types for the request.

Action. An action code for the control.

AttachedFile. A file to append to PostData if the POST or PUT methods are used.

Authorization. The Authorization string to be sent to the server.

ContentType. Content type for posted data.

From. The email address of the HTTP agent (optional).

HTTPVersion. The version of HTTP used (default is HTTP/1.0).

IfModifiedSince. A date determining the maximum age of the desired document.

LocalHost. The name of the local host. When connected, the IP address of the interface through which the connection was made.

LocalFile. The path to a local file for downloading. If the file exists, it is overwritten. (optional)

OtherHeaders. Other headers as determined by the user (optional).

Password. A password if Basic authentication is to be used.

PostData. The data to post with the URL if the POST method is used.

Pragma. A browser/server specific header line (optional).

ProxyPort. Port for the proxy server (default 80).

ProxyServer. Name or IP address of a proxy server (optional).

Referer. Referer URL/document (optional).

SocketHandle. The handle of the main socket used by the control.

StatusLine. The first line of the last server response.

URL. The URL to fetch.

URLPath. The path for the URL.

URLPort. The port for the URL.

URLScheme. The scheme for the URL.

URLServer. The server for the URL.

User. A user name if Basic authentication is to be used.

UserAgent. Information about the user agent (browser).

WinsockInfo. Identifying information about the loaded Winsock stack.

WinsockLoaded. Loads and unloads Winsock on demand.

WinsockMaxDatagramSize. Size in bytes of the largest UDP datagram that can be sent or received.

WinsockMaxSockets. Maximum number of sockets available to a single process.

WinsockPath. The path to the Winsock DLL used.

WinsockStatus. The status of the Winsock stack.

EVENTS

Connected. Fired immediately after a connection completes (or fails).

Disconnected. Fired when a connection is closed.

EndTransfer. Fired when a document finishes transferring.

Error. Information about errors during data delivery.

Header. Fired every time a header line comes in.

StartTransfer. Fired when a document starts transferring (after the headers).

Transfer. Fired while a document transfers (delivers document).