MPNSubscriptionDelegate

Event handler called when the MPNSubscriptionDelegate instance is added to an MPNSubscription through MPNSubscription.addDelegate(_:).

This is the first event to be fired on the delegate.

Event handler called when the MPNSubscriptionDelegate instance is removed from an MPNSubscription through MPNSubscription.removeDelegate(_:).

This is the last event to be fired on the delegate.

Event handler called when an MPNSubscription has been successfully subscribed to on the server’s MPN Module.

This event handler is always called before other events related to the same subscription.

Note that this event can be called multiple times in the life of an MPNSubscription instance only in case it is subscribed multiple times through LightstreamerClient.unsubscribeMPN(_:) and LightstreamerClient.subscribeMPN(_:coalescing:). Two consecutive calls to this method are not possible, as before a second mpnSubscriptionDidSubscribe: event an mpnSubscriptionDidUnsubscribe(_:) event is always fired.

Event handler called when an MPNSubscription has been successfully unsubscribed from on the server’s MPN Module.

After this call no more events can be received until a new mpnSubscriptionDidSubscribe(_:) event.

Note that this event can be called multiple times in the life of an MPNSubscription instance only in case it is subscribed multiple times through LightstreamerClient.unsubscribeMPN(_:) and LightstreamerClient.subscribeMPN(_:coalescing:). Two consecutive calls to this method are not possible, as before a second mpnSubscriptionDidUnsubscribe: event an mpnSubscriptionDidSubscribe(_:) event is always fired.

Event handler called when the server notifies an error while subscribing to an MPNSubscription.

By implementing this method it is possible to perform recovery actions.

The error code can be one of the following:

• 17 - bad Data Adapter name or default Data Adapter not defined for the current Adapter Set.

• 21 - bad Group name.

• 22 - bad Group name for this Schema.

• 23 - bad Schema name.

• 24 - mode not allowed for an Item.

• 30 - subscriptions are not allowed by the current license terms (for special licenses only).

• 40 - the MPN Module is disabled, either by configuration or by license restrictions.

• 41 - the request failed because of some internal resource error (e.g. database connection, timeout etc.).

• 43 - invalid or unknown application ID.

• 44 - invalid syntax in trigger expression.

• 45 - invalid or unknown MPN device ID.

• 46 - invalid or unknown MPN subscription ID (for MPN subscription modifications).

• 47 - invalid argument name in notification format or trigger expression.

• 48 - MPN device suspended.

• 49 - one or more subscription properties exceed maximum size.

• 50 - no items or fields have been specified.

• 52 - the notification format is not a valid JSON structure.

• 53 - the notification format is empty.

• 66 - an unexpected exception was thrown by the Metadata Adapter while authorizing the connection.

• 68 - the Server could not fulfill the request because of an internal error.

• <= 0 - the Metadata Adapter has refused the subscription request; the code value is dependent on the specific Metadata Adapter implementation.

Event handler called when the server notifies an error while unsubscribing from an MPNSubscription.

By implementing this method it is possible to perform recovery actions.

The error code can be one of the following:

• 30 - subscriptions are not allowed by the current license terms (for special licenses only).

• 40 - the MPN Module is disabled, either by configuration or by license restrictions.

• 41 - the request failed because of some internal resource error (e.g. database connection, timeout etc.).

• 43 - invalid or unknown application ID.

• 45 - invalid or unknown MPN device ID.

• 46 - invalid or unknown MPN subscription ID.

• 48 - MPN device suspended.

• 66 - an unexpected exception was thrown by the Metadata Adapter while authorizing the connection.

• 68 - the Server could not fulfill the request because of an internal error.

• <= 0 - the Metadata Adapter has refused the unsubscription request; the code value is dependent on the specific Metadata Adapter implementation.

Event handler called when the server notifies that an MPNSubscription did trigger.

For this event to be called the MPNSubscription must have a MPNSubscription.triggerExpression set and it must have been evaluated to true at least once.

Note that this event can be called multiple times in the life of an MPNSubscription instance only in case it is subscribed multiple times through LightstreamerClient.unsubscribeMPN(_:) and LightstreamerClient.subscribeMPN(_:coalescing:). Two consecutive calls to this method are not possible.

Note also that in some server clustering configurations this event may not be called. The corrisponding push notification is always sent, though.

Event handler called when the server notifies that an MPNSubscription changed its status.

Note that in some server clustering configurations the status change for the MPN subscription’s trigger event may not be called. The corrisponding push notification is always sent, though.

Event handler called each time the value of a property of MPNSubscription is changed.

Properties can be modified by direct calls to them or by server sent events. A propery may be changed by a server sent event when the MPN subscription is modified, or when two MPN subscriptions coalesce (see LightstreamerClient.subscribeMPN(_:coalescing:)).

Possible property names are the following:

• mode

• group

• schema

• adapter

• notification_format

• trigger

• requested_buffer_size

• requested_max_frequency

• status_timestamp

Event handler called when the server notifies an error while modifying the trigger expression or the notification format of an MPNSubscription.

By implementing this method it is possible to perform recovery actions.

The error code can be one of the following:

• 3 - Protocol mismatch.

• 22 - bad Group name for this Schema.

• 23 - bad Schema name.

• 40 - the MPN Module is disabled, either by configuration or by license restrictions.

• 41 - the request failed because of some internal resource error (e.g. database connection, timeout etc.).

• 44 - invalid syntax in trigger expression.

• 45 - invalid or unknown MPN device ID.

• 46 - invalid or unknown MPN subscription ID (for MPN subscription modifications).

• 47 - invalid argument name in notification format or trigger expression.

• 48 - MPN device suspended.

• 49 - one or more subscription properties exceed maximum size.

• 50 - no items or fields have been specified.

• 52 - the notification format is not a valid JSON structure.

• 53 - the notification format is empty.

• 56 - MPN subscription to be modified had changed.

• 66 - an unexpected exception was thrown by the Metadata Adapter while authorizing the connection.

• 68 - the Server could not fulfill the request because of an internal error.

• <= 0 - the Metadata Adapter has refused the subscription request; the code value is dependent on the specific Metadata Adapter implementation.