HTTP Component

Properties   Methods   Events   Configuration Settings   Errors  

The HTTP Component can be used to retrieve documents from the World Wide Web.

Syntax

TipwHTTP

Remarks

The HTTP Component supports both plaintext and SSL/TLS connections. When connecting over SSL/TLS the SSLServerAuthentication event allows you to check the server identity and other security attributes. The SSLStatus event provides information about the SSL handshake. Additional SSL related settings are also supported via the Config method.

The HTTP Component implements a standard HTTP client through a simple plug-and-play interface as defined in RFCs 1945 and 2616 with the added option of SSL security.

The component 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.

To receive a document call the Get method with the URL parameter. Data can be POST-ed to the HTTP server by assigning it to the PostData property and then calling the Post method.

The PUT method is also supported. You should specify the User and Password properties or alternatively the Authorization and call the Put method with the specified URL. The AttachedFile will be sent to the server.

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

Property List


The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

AcceptA list of acceptable MIME types for the request.
AllowHTTPCompressionEnables HTTP compression for receiving data.
AttachedFileA file to append to PostData if the POST or PUT methods are used.
AuthorizationThe Authorization string to be sent to the server.
AuthSchemeThe authentication scheme to use when server authorization is required.
ConnectedShows whether the component is connected.
ContentTypeContent type for posts and puts.
CookiesCollection of cookies.
FirewallA set of properties related to firewall access.
FollowRedirectsDetermines what happens when the server issues a redirect.
FromThe email address of the HTTP agent (optional).
HTTPMethodThe HTTP method used for the request.
HTTPVersionThe HTTP Version used by the component.
IdleThe current status of the component.
IfModifiedSinceA date determining the maximum age of the desired document.
LocalFileThe path to a local file for downloading. If the file exists, it is overwritten.
LocalHostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
OtherHeadersOther headers as determined by the user (optional).
ParsedHeadersCollection of headers returned from the last request.
PasswordA password if authentication is to be used.
PostDataThe data to post with the URL if the POST method is used.
PragmaA browser/server specific header line (optional).
ProxyA set of properties related to proxy access.
RangeThe byte-range to be sent to the server.
RefererReferer URL/document (optional).
SSLAcceptServerCertEncodedThe certificate (PEM/base64 encoded).
SSLCertEncodedThe certificate (PEM/base64 encoded).
SSLCertStoreThe name of the certificate store for the client certificate.
SSLCertStorePasswordIf the certificate store is of a type that requires a password, this property is used to specify that password in order to open the certificate store.
SSLCertStoreTypeThe type of certificate store for this certificate.
SSLCertSubjectThe subject of the certificate used for client authentication.
SSLServerCertEncodedThe certificate (PEM/base64 encoded).
StatusLineThe first line of the last server response.
TimeoutA timeout for the component.
TransferredDataThe contents of the last response from the server.
TransferredDataLimitThe maximum of data to be transferred.
TransferredHeadersThe full set of headers as received from the server.
URLThe URL to fetch.
URLPathThe path for the URL.
URLPortThe port for the URL.
URLSchemeThe scheme for the URL.
URLServerThe server for the URL.
UserA user name if authentication is to be used.

Method List


The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

AddCookieAdds a cookie and the corresponding value to the outgoing request headers.
ConfigSets or retrieves a configuration setting.
DeleteDeletes an object on the server.
DoEventsProcesses events from the internal message queue.
GetFetch the document using the HTTP GET method.
HeadFetches the document headers using the HTTP HEAD method.
InterruptInterrupt the current method.
PostPosts data to the HTTP server using the HTTP POST method.
PutSends data to the HTTP server using the HTTP PUT method.
ResetReset the component.
ResetHeadersResets all HTTP Headers, Cookies, LocalFile , and AttachedFile .
SetDownloadStreamSets the stream to which the downloaded data from the server will be written.
SetUploadStreamSets the stream to be uploaded to the server.

Event List


The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

ConnectedFired immediately after a connection completes (or fails).
ConnectionStatusFired to indicate changes in connection state.
DisconnectedFired when a connection is closed.
EndTransferFired when a document finishes transferring.
ErrorInformation about errors during data delivery.
HeaderFired every time a header line comes in.
LogFires once for each log message.
RedirectFired when a redirection is received from the server.
SetCookieFired for every cookie set by the server.
SSLServerAuthenticationFired after the server presents its certificate to the client.
SSLStatusShows the progress of the secure connection.
StartTransferFired when a document starts transferring (after the headers).
StatusFired when the HTTP status line is received from the server.
TransferFired while a document transfers (delivers document).

Configuration Settings


The following is a list of configuration settings for the component with short descriptions. Click on the links for further details.

AcceptEncodingUsed to tell the server which types of content encodings the client supports.
AllowHTTPCompressionThis property enables HTTP compression for receiving data.
AllowHTTPFallbackWhether HTTP/2 connections are permitted to fallback to HTTP/1.1.
AppendWhether to append data to LocalFile.
AuthorizationThe Authorization string to be sent to the server.
BytesTransferredContains the number of bytes transferred in the response data.
ChunkSizeSpecifies the chunk size in bytes when using chunked encoding.
CompressHTTPRequestSet to true to compress the body of a PUT or POST request.
EncodeURLIf set to true the URL will be encoded by the component.
FollowRedirectsDetermines what happens when the server issues a redirect.
GetOn302RedirectIf set to true the component will perform a GET on the new location.
HTTP2HeadersWithoutIndexingHTTP2 headers that should not update the dynamic header table with incremental indexing.
HTTPVersionThe version of HTTP used by the component.
IfModifiedSinceA date determining the maximum age of the desired document.
KeepAliveDetermines whether the HTTP connection is closed after completion of the request.
KerberosSPNThe Service Principal Name for the Kerberos Domain Controller.
LogLevelThe level of detail that is logged.
MaxRedirectAttemptsLimits the number of redirects that are followed in a request.
NegotiatedHTTPVersionThe negotiated HTTP version.
OtherHeadersOther headers as determined by the user (optional).
ProxyAuthorizationThe authorization string to be sent to the proxy server.
ProxyAuthSchemeThe authorization scheme to be used for the proxy.
ProxyPasswordA password if authentication is to be used for the proxy.
ProxyPortPort for the proxy server (default 80).
ProxyServerName or IP address of a proxy server (optional).
ProxyUserA user name if authentication is to be used for the proxy.
SentHeadersThe full set of headers as sent by the client.
StatusLineThe first line of the last response from the server.
TransferredDataThe contents of the last response from the server.
TransferredDataLimitThe maximum number of incoming bytes to be stored by the component.
TransferredHeadersThe full set of headers as received from the server.
TransferredRequestThe full request as sent by the client.
UseChunkedEncodingEnables or Disables HTTP chunked encoding for transfers.
UseIDNsWhether to encode hostnames to internationalized domain names.
UserAgentInformation about the user agent (browser).
CloseStreamAfterTransferIf true, the component will close the upload or download stream after the transfer.
ConnectionTimeoutSets a separate timeout value for establishing a connection.
FirewallAutoDetectTells the component whether or not to automatically detect and use firewall system settings, if available.
FirewallHostName or IP address of firewall (optional).
FirewallPasswordPassword to be used if authentication is to be used when connecting through the firewall.
FirewallPortThe TCP port for the FirewallHost;.
FirewallTypeDetermines the type of firewall to connect through.
FirewallUserA user name if authentication is to be used connecting through a firewall.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
LingerWhen set to True, connections are terminated gracefully.
LingerTimeTime in seconds to have the connection linger.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the component binds.
MaxLineLengthThe maximum amount of data to accumulate when no EOL is found.
MaxTransferRateThe transfer rate limit in bytes per second.
ProxyExceptionsListA semicolon separated list of hosts and IPs to bypass when using a proxy.
TCPKeepAliveDetermines whether or not the keep alive socket option is enabled.
TcpNoDelayWhether or not to delay when sending packets.
UseIPv6Whether to use IPv6.
LogSSLPacketsControls whether SSL packets are logged when using the internal security API.
OpenSSLCADirThe path to a directory containing CA certificates.
OpenSSLCAFileName of the file containing the list of CA's trusted by your application.
OpenSSLCipherListA string that controls the ciphers to be used by SSL.
OpenSSLPrngSeedDataThe data to seed the pseudo random number generator (PRNG).
ReuseSSLSessionDetermines if the SSL session is reused.
SSLCACertsA newline separated list of CA certificate to use during SSL client authentication.
SSLCheckCRLWhether to check the Certificate Revocation List for the server certificate.
SSLCipherStrengthThe minimum cipher strength used for bulk encryption.
SSLEnabledCipherSuitesThe cipher suite to be used in an SSL negotiation.
SSLEnabledProtocolsUsed to enable/disable the supported security protocols.
SSLEnableRenegotiationWhether the renegotiation_info SSL extension is supported.
SSLIncludeCertChainWhether the entire certificate chain is included in the SSLServerAuthentication event.
SSLNegotiatedCipherReturns the negotiated ciphersuite.
SSLNegotiatedCipherStrengthReturns the negotiated ciphersuite strength.
SSLNegotiatedCipherSuiteReturns the negotiated ciphersuite.
SSLNegotiatedKeyExchangeReturns the negotiated key exchange algorithm.
SSLNegotiatedKeyExchangeStrengthReturns the negotiated key exchange algorithm strength.
SSLNegotiatedVersionReturns the negotiated protocol version.
SSLProviderThe name of the security provider to use.
SSLSecurityFlagsFlags that control certificate verification.
SSLServerCACertsA newline separated list of CA certificate to use during SSL server certificate validation.
TLS12SignatureAlgorithmsDefines the allowed TLS 1.2 signature algorithms when UseInternalSecurityAPI is True.
TLS12SupportedGroupsThe supported groups for ECC.
TLS13KeyShareGroupsThe groups for which to pregenerate key shares.
TLS13SignatureAlgorithmsThe allowed certificate signature algorithms.
TLS13SupportedGroupsThe supported groups for (EC)DHE key exchange.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
UseInternalSecurityAPITells the component whether or not to use the system security libraries or an internal implementation.

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IPWorks 2020 Delphi Edition - Version 20.0 [Build 8307]