JSON Control

Properties Methods Events Configuration Settings Errors

The JSON Component can be used to easily integrate with web services that produce JSON output.

Syntax

JSON

Remarks

The JSON Control implements a standard JSON client .

The control contains a number of properties that map directly to HTTP request headers. All JSON data received is parsed by the control and provided to the user through properties such as XPath, XElement, XText, etc. which allow traversal of the document structure. The Header event will provide the HTTP headers as returned by the server.

To receive a document, call the Get method with the URL to retrieve specified in the URL parameter. The control will automatically parse the JSON data. Call the Delete method to delete a resource specified by the URL parameter.

The other two JSON operations are for creating and updating resources. Some people wish to use the Post method for creating resources and the Put method for updating resources. Others choose to use the methods vice versa, or just one for both operations. So, you can POST JSON data to the HTTP server by assigning it to the PostData property and then calling the Post method. Alternatively, you may use the PUT method instead.

To add authorization credentials to an outgoing request, you should specify the User and Password properties. The JSON Control supports Basic, Digest, and NTLM authentication through the AuthScheme property.

Property List

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


Accept	A list of acceptable MIME types for the request.
Authorization	The Authorization string to be sent to the server.
AuthScheme	The authentication scheme to use when server authorization is required.
BuildDOM	When True, an internal object model of the JSON document is created.
Connected	Shows whether the component is connected.
ContentType	Content type for posts and puts.
CookieCount	The number of records in the Cookie arrays.
CookieDomain	The domain of a received cookie.
CookieExpiration	This property contains an expiration time for the cookie (if provided by the server).
CookieName	The name of the cookie.
CookiePath	This property contains a path name to limit the cookie to (if provided by the server).
CookieSecure	This property contains the security flag of the received cookie.
CookieValue	This property contains the value of the cookie.
FirewallAutoDetect	This property tells the component whether or not to automatically detect and use firewall system settings, if available.
FirewallType	This property determines the type of firewall to connect through.
FirewallHost	This property contains the name or IP address of firewall (optional).
FirewallPassword	This property contains a password if authentication is to be used when connecting through the firewall.
FirewallPort	This property contains the TCP port for the firewall Host .
FirewallUser	This property contains a user name if authentication is to be used connecting through a firewall.
FollowRedirects	Determines what happens when the server issues a redirect.
From	The email address of the HTTP agent (optional).
HTTPMethod	The HTTP method used for the request.
Idle	The current status of the component.
IfModifiedSince	A date determining the maximum age of the desired document.
LocalFile	The path to a local file for downloading. If the file exists, it is overwritten.
LocalHost	The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
OtherHeaders	Other headers as determined by the user (optional).
ParsedHeaderCount	The number of records in the ParsedHeader arrays.
ParsedHeaderField	This property contains the name of the HTTP header (same case as it is delivered).
ParsedHeaderValue	This property contains the header contents.
Password	A password if authentication is to be used.
PostData	The data to post with the URL if the POST method is used.
ProxyAuthScheme	This property is used to tell the component which type of authorization to perform when connecting to the proxy.
ProxyAutoDetect	This property tells the component whether or not to automatically detect and use proxy system settings, if available.
ProxyPassword	This property contains a password if authentication is to be used for the proxy.
ProxyPort	This property contains the TCP port for the proxy Server (default 80).
ProxyServer	If a proxy Server is given, then the HTTP request is sent to the proxy instead of the server otherwise specified.
ProxyUser	This property contains a user name, if authentication is to be used for the proxy.
Referer	Referer URL/document (optional).
StatusLine	The first line of the last server response.
Timeout	A timeout for the component.
TransferredData	The contents of the last response from the server.
TransferredDataLimit	The maximum of bytes of data to be transferred.
TransferredHeaders	The full set of headers as received from the server.
URL	The URL to post information to.
User	A user name if authentication is to be used.
XChildrenCount	The number of records in the XChild arrays.
XChildName	The Name property provides the local name of the element.
XChildXText	This property contains the inner text of the element.
XElement	The name of the current element.
XErrorPath	An XPath to check the server response for errors.
XParent	The parent of the current element.
XPath	Provides a way to point to a specific element in the response.
XSubTree	A snapshot of the current element in the document.
XText	The text of the current element.

Method List

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


AddCookie	Adds a cookie and the corresponding value to the outgoing request headers.
Config	Sets or retrieves a configuration setting .
Delete	Deletes an object on the server.
DoEvents	Processes events from the internal message queue.
Get	Fetches the document.
HasXPath	Determines whether a specific element exists in the document.
Input	Provides input to the parser.
Interrupt	Interrupt the current method.
ParseFile	Loads a JSON file into the component.
Post	Posts data to the HTTP server using the HTTP POST method.
Put	Sends data to the HTTP server using the HTTP PUT method.
Reset	Resets the component.

Event List

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


Characters	Fired for plain text segments of the input stream.
Connected	Fired immediately after a connection completes (or fails).
ConnectionStatus	Fired to indicate changes in connection state.
Disconnected	Fired when a connection is closed.
EndElement	Fired when an end-element tag is encountered.
Error	Information about errors during data delivery.
Header	Fired every time a header line comes in.
IgnorableWhitespace	Fired when a section of ignorable whitespace is encountered.
Redirect	Fired when a redirection is received from the server.
SetCookie	Fired for every cookie set by the server.
StartElement	Fired when a new element is encountered in the document.
Status	Fired when the HTTP status line is received from the server.

Configuration Settings

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


CacheContent	If true, the original JSON is stored internally in a buffer.
RequireJSONContentType	Controls whether the component checks for a JSON Content-Type value in the response.
AcceptEncoding	Used to tell the server which types of content encodings the client supports.
AllowHTTPCompression	This property enables HTTP compression for receiving data.
AllowIdenticalRedirectURL	Allow redirects to the same URL.
Append	Whether to append data to LocalFile.
Authorization	The Authorization string to be sent to the server.
BytesTransferred	Contains the number of bytes transferred in the response data.
EncodeURL	If set to true the URL will be encoded by the component.
FollowRedirects	Determines what happens when the server issues a redirect.
GetOn302Redirect	If set to true the component will perform a GET on the new location.
HTTPVersion	The version of HTTP used by the component.
IfModifiedSince	A date determining the maximum age of the desired document.
KeepAlive	Determines whether the HTTP connection is closed after completion of the request.
MaxRedirectAttempts	Limits the number of redirects that are followed in a request.
OtherHeaders	Other headers as determined by the user (optional).
ProxyAuthorization	The authorization string to be sent to the proxy server.
ProxyAuthScheme	The authorization scheme to be used for the proxy.
ProxyPassword	A password if authentication is to be used for the proxy.
ProxyPort	Port for the proxy server (default 80).
ProxyServer	Name or IP address of a proxy server (optional).
ProxyUser	A user name if authentication is to be used for the proxy.
TransferredDataLimit	The maximum number of incoming bytes to be stored by the component.
TransferredHeaders	The full set of headers as received from the server.
UseChunkedEncoding	Enables or Disables HTTP chunked encoding for transfers.
ChunkSize	Specifies the chunk size in bytes when using chunked encoding.
UserAgent	Information about the user agent (browser).
KerberosSPN	The Service Principal Name for the Kerberos Domain Controller.
ConnectionTimeout	Sets a separate timeout value for establishing a connection.
FirewallAutoDetect	Tells the component whether or not to automatically detect and use firewall system settings, if available.
FirewallHost	Name or IP address of firewall (optional).
FirewallPassword	Password to be used if authentication is to be used when connecting through the firewall.
FirewallPort	The TCP port for the FirewallHost;.
FirewallType	Determines the type of firewall to connect through.
FirewallUser	A user name if authentication is to be used connecting through a firewall.
KeepAliveTime	The inactivity time in milliseconds before a TCP keep-alive packet is sent.
KeepAliveInterval	The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
Linger	When set to True, connections are terminated gracefully.
LingerTime	Time in seconds to have the connection linger.
LocalHost	The name of the local host through which connections are initiated or accepted.
LocalPort	The TCP port in the local host where the component binds.
MaxLineLength	The maximum amount of data to accumulate when no EOL is found.
MaxTransferRate	The transfer rate limit in bytes per second.
RecordLength	The length of received data records.
TCPKeepAlive	Determines whether or not the keep alive socket option is enabled.
UseIPv6	Whether to use IPv6.
TcpNoDelay	Whether or not to delay when sending packets.
AbsoluteTimeout	Determines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallData	Used to send extra data to the firewall.
InBufferSize	The size in bytes of the incoming queue of the socket.
OutBufferSize	The size in bytes of the outgoing queue of the socket.
CodePage	The system code page used for Unicode to Multibyte translations.