Caplin Systems - StreamLinkJS API Documentation

Class

caplin.streamlink

StreamLink

The main StreamLink Class.

To create an instance of this class, use the caplin.streamlink.StreamLinkFactory.

Constructor Summary

Attributes	Name and Description
	`caplin.streamlink.StreamLink()`

Method Summary

Attributes	Name and Description
	`void addConnectionListener(caplin.streamlink.ConnectionListener connectionListener)` Adds a caplin.streamlink.ConnectionListener to this StreamLink instance.
	`void connect()` Instructs this `StreamLink` instance to attempt to connect to the Liberator.
	`caplin.streamlink.CommandSubscription createSubject(String subject, caplin.streamlink.SubjectType subjectType, caplin.streamlink.CommandListener commandListener, Map commandParameters)` Creates a subject in the Liberator.
	`void deleteSubject(String subject, caplin.streamlink.CommandListener commandListener)` Deletes a subject in the Liberator.
	`void disconnect()` Instructs this `StreamLink` instance to disconnect from the Liberator.
	`caplin.streamlink.Logger getLogger()` Returns the StreamLink logger object.
	`void getVersion()` Returns the version number and build identifier for this version of the StreamLink library.
	`caplin.streamlink.CommandSubscription publishToSubject(String subject, Map fieldData, caplin.streamlink.CommandListener commandListener, Map commandParameters)` Publishes data to a subject.
	`void removeConnectionListener(caplin.streamlink.ConnectionListener connectionListener)` Removes a previously added caplin.streamlink.ConnectionListener from this StreamLink instance.
	`caplin.streamlink.Subscription subscribe(String subject, caplin.streamlink.SubscriptionListener subscriptionListener, Map subscriptionParameters)` Subscribes to a subject to receive updates.
	`caplin.streamlink.CommandSubscription throttleEverything(caplin.streamlink.ThrottleCommand throttleCommand, caplin.streamlink.CommandListener commandListener, Map commandParameters)` Throttles all the currently subscribed subjects, reducing the number of updates that are sent every second.
	`caplin.streamlink.CommandSubscription throttleSubject(String subject, caplin.streamlink.ThrottleCommand throttleCommand, caplin.streamlink.CommandListener commandListener, Map commandParameters)` Throttles the specified subject, reducing the number of updates that are sent every second.

Constructor Detail

► caplin.streamlink.StreamLink()

Method Detail

► void addConnectionListener(caplin.streamlink.ConnectionListener connectionListener)

Adds a caplin.streamlink.ConnectionListener to this StreamLink instance. This connectionListener is called whenever a connection event occurs.

Parameters

caplin.streamlink.ConnectionListener connectionListener The ConnectionListener to be added.

► void connect()

Instructs this StreamLink instance to attempt to connect to the Liberator.

► caplin.streamlink.CommandSubscription createSubject(String subject, caplin.streamlink.SubjectType subjectType, caplin.streamlink.CommandListener commandListener, Map commandParameters)

Creates a subject in the Liberator.

The commandParameters argument takes the following JSON configuration attributes:

Attribute name	Type	Default	Optional	Description
persistent	boolean	false	Yes	When true, the throttle setting for this command persists across a failure of the connection to Liberator and subsequent reconnection. When false, the throttle setting only applies to the current Liberator session and does not persist following a connection failure. For a fuller explanation, see the 'Persistence' section of the StreamLink Overview document.

Attribute name

Type

Default

Optional

Description

persistent

boolean

false

Yes

When true, the throttle setting for this command persists across a failure of the connection to Liberator and subsequent reconnection.

When false, the throttle setting only applies to the current Liberator session and does not persist following a connection failure.

For a fuller explanation, see the 'Persistence' section of the StreamLink Overview document.

Parameters

String	subject	The name of the subject to create.
caplin.streamlink.SubjectType	subjectType	The type of subject to create.
caplin.streamlink.CommandListener	commandListener	A listener that is called to provide information about the result of the "create subject" command.
Map	commandParameters	Optional JSON configuration attributes.

Returns: {caplin.streamlink.CommandSubscription} Information about the 'create subject' command. If the commandParameters made the command persistent, you can subsequently cancel this by calling the CommandSubscription's unPersist() method.

► void deleteSubject(String subject, caplin.streamlink.CommandListener commandListener)

Deletes a subject in the Liberator.

Parameters

String	subject	The name of the subject to delete.
caplin.streamlink.CommandListener	commandListener	A listener that is called to provide information about the result of the 'delete subject' command.

► void disconnect()

Instructs this StreamLink instance to disconnect from the Liberator.

► caplin.streamlink.Logger getLogger()

Returns the StreamLink logger object. You can receive StreamLink log messages by adding your own caplin.streamlink.LogListener to this object.

Returns: {caplin.streamlink.Logger} The Logger object of this StreamLink instance.

► void getVersion()

Returns the version number and build identifier for this version of the StreamLink library.

Returns: String the version number and build identifier for this version of the StreamLink library.

► caplin.streamlink.CommandSubscription publishToSubject(String subject, Map fieldData, caplin.streamlink.CommandListener commandListener, Map commandParameters)

Publishes data to a subject.

The commandParameters argument takes the following JSON configuration attributes:

Attribute name	Type	Default	Optional	Description
persistent	boolean	false	Yes	When true, if the connection to the Liberator fails after publication, the data is resent when StreamLink reconnects. When false, if the connection to the Liberator fails after publication, the data is not resent when StreamLink reconnects.

Attribute name

Type

Default

Optional

Description

persistent

boolean

false

Yes

When true, if the connection to the Liberator fails after publication, the data is resent when StreamLink reconnects.

When false, if the connection to the Liberator fails after publication, the data is not resent when StreamLink reconnects.

Parameters

String	subject	The subject to publish to.
Map	fieldData	The data, as key-value pairs, to be published to the subject.
caplin.streamlink.CommandListener	commandListener	A listener that receives notification of the publish command's success or failure.
Map	commandParameters	Optional JSON configuration attributes.

Returns: {caplin.streamlink.CommandSubscription} Information about the 'publish' command. If the commandParameters made the command persistent, you can subsequently cancel this by calling the CommandSubscription's unPersist() method.

► void removeConnectionListener(caplin.streamlink.ConnectionListener connectionListener)

Removes a previously added caplin.streamlink.ConnectionListener from this StreamLink instance. After removal, no further callbacks are received by this ConnectionListener.

Parameters

caplin.streamlink.ConnectionListener

connectionListener

The ConnectionListener to be removed.

► caplin.streamlink.Subscription subscribe(String subject, caplin.streamlink.SubscriptionListener subscriptionListener, Map subscriptionParameters)

Subscribes to a subject to receive updates.

The subscriptionParameters argument takes the following JSON configuration attributes:

Attribute name	Type	Default	Optional	Description
fields	[string]	All fields are subscribed to.	Yes	An array of the the fields to subscribe to. For example: `["field_a","field_b","field_d"]`
filter	{value: string, image: boolean}	No filter is applied.	Yes	A filter that restricts the number of field updates that will be received. The `value` string specifies the filter criteria. For example: `(dLast >50) & (dVolumeAcc > 1000)/code>, means that the Liberator sends updates only when the value of the field dLast is greater than 50 and the dVolumeAcc field is greater than 1000.` `When the image boolean is true, the filter not applied until after the data within a particular update has been applied to the image of the data item. When image is false, the update filter is applied just to the data within a particular update of the data item. For more information about filters, see the 'Filtering data' section of the document StreamLink Overview.`
window	{start: int, size: int}	Updates are returned for the whole container (subject to any filter applied).	Yes	When the subscription is to a container, this attribute defines a window that begins at the element defined by `start`, and is `size` elements long. Liberator only returns updates for the elements that are in the window. The first element in a container starts at position 0 (zero).

Parameters

String	subject	The subject to subscribe to.
caplin.streamlink.SubscriptionListener	subscriptionListener	A listener that is called to provide information about the result of the subscription request, the subscribed data, and subsequent updates to that data.
Map	subscriptionParameters	Optional JSON configuration attributes.

Returns: {caplin.streamlink.Subscription} The subscription data. You can subsequently unsubscribe from the subject by calling this object's unsubcribe() method.

► caplin.streamlink.CommandSubscription throttleEverything(caplin.streamlink.ThrottleCommand throttleCommand, caplin.streamlink.CommandListener commandListener, Map commandParameters)

Throttles all the currently subscribed subjects, reducing the number of updates that are sent every second.

For a fuller explanation of throttling, refer to the 'Throttling' section of the document StreamLink Overview.

Parameters

caplin.streamlink.ThrottleCommand	throttleCommand	The throttle command to apply.
caplin.streamlink.CommandListener	commandListener	A listener that is called to provide information about the result of the throttle command.
Map	commandParameters	Optional JSON configuration attributes; for details, see the `commandParameters` parameter of `throttleSubject().`

Returns: {caplin.streamlink.CommandSubscription} Information about the 'throttle' command. If the commandParameters made the command persistent, you can subsequently cancel this by calling the CommandSubscription's unPersist() method.

► caplin.streamlink.CommandSubscription throttleSubject(String subject, caplin.streamlink.ThrottleCommand throttleCommand, caplin.streamlink.CommandListener commandListener, Map commandParameters)

Throttles the specified subject, reducing the number of updates that are sent every second.

For a fuller explanation of throttling, refer to the 'Throttling' section of the document StreamLink Overview.

The commandParameters argument takes the following JSON configuration attributes:

Attribute name	Type	Default	Optional	Description
persistent	boolean	false	Yes	When true, the throttle setting for this command persists across a failure of the connection to Liberator and subsequent reconnection. When false, the throttle setting only applies to the current Liberator session and does not persist following a connection failure. For a fuller explanation, see the 'Persistence' section of the StreamLink Overview document.

Attribute name

Type

Default

Optional

Description

persistent

boolean

false

Yes

When true, the throttle setting for this command persists across a failure of the connection to Liberator and subsequent reconnection.

When false, the throttle setting only applies to the current Liberator session and does not persist following a connection failure.

For a fuller explanation, see the 'Persistence' section of the StreamLink Overview document.

Parameters

String	subject	The subject for which received data updates are to be throttled.
caplin.streamlink.ThrottleCommand	throttleCommand	The Throttle command to apply.
caplin.streamlink.CommandListener	commandListener	A listener that is called to provide information about the result of the throttle command.
Map	commandParameters	Optional JSON configuration attributes.

Returns: {caplin.streamlink.CommandSubscription} Information about the 'throttle' command. If the commandParameters made the command persistent, you can subsequently cancel this by calling the CommandSubscription's unPersist() method.