LSMPNSubscriptionDelegate Protocol Reference

Conforms to NSObject
Declared in LSMPNSubscriptionDelegate.h

Overview

Protocol to be implemented to receive LSMPNSubscription events including subscription/unsubscription, triggering and status change.

Events for these delegates are dispatched by a different thread than the one that generates them. This means that, upon reception of an event, it is possible that the internal state of the client has changed. On the other hand, all the notifications for a single LSLightstreamerClient, including notifications to LSClientDelegate, LSSubscriptionDelegate, LSClientMessageDelegate, LSMPNDeviceDelegate and LSMPNSubscriptionDelegate will be dispatched by the same thread.

– mpnSubscriptionDidAddDelegate:

Event handler called when the LSMPNSubscriptionDelegate instance is added to an LSMPNSubscription through [LSMPNSubscription addDelegate:].

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

- (void)mpnSubscriptionDidAddDelegate:(nonnull LSMPNSubscription *)subscription

Parameters

subscription

The LSMPNSubscription this instance was added to.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscriptionDidRemoveDelegate:

Event handler called when the LSMPNSubscriptionDelegate instance is removed from an LSMPNSubscription through [LSMPNSubscription removeDelegate:].

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

- (void)mpnSubscriptionDidRemoveDelegate:(nonnull LSMPNSubscription *)subscription

Parameters

subscription

The LSMPNSubscription this instance was removed from.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscriptionDidSubscribe:

Event handler called when an LSMPNSubscription 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 instance only in case it is subscribed multiple times through [LSLightstreamerClient unsubscribeMPN:] and [LSLightstreamerClient subscribeMPN:coalescing:]. Two consecutive calls to this method are not possible, as before a second mpnSubscriptionDidSubscribe: event an mpnSubscriptionDidUnsubscribe: event is always fired.

- (void)mpnSubscriptionDidSubscribe:(nonnull LSMPNSubscription *)subscription

Parameters

subscription

The LSMPNSubscription involved.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscriptionDidUnsubscribe:

Event handler called when an LSMPNSubscription 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 instance only in case it is subscribed multiple times through [LSLightstreamerClient unsubscribeMPN:] and [LSLightstreamerClient subscribeMPN:coalescing:]. Two consecutive calls to this method are not possible, as before a second mpnSubscriptionDidUnsubscribe: event an mpnSubscriptionDidSubscribe: event is always fired.

- (void)mpnSubscriptionDidUnsubscribe:(nonnull LSMPNSubscription *)subscription

Parameters

subscription

The LSMPNSubscription involved.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscription:didFailSubscriptionWithErrorCode:message:

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

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.

- (void)mpnSubscription:(nonnull LSMPNSubscription *)subscription didFailSubscriptionWithErrorCode:(NSInteger)code message:(nullable NSString *)message

Parameters

subscription

The LSMPNSubscription involved.

code

The error code sent by the Server.

message

The description of the error sent by the Server; it can be nil.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscription:didFailUnsubscriptionWithErrorCode:message:

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

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.

- (void)mpnSubscription:(nonnull LSMPNSubscription *)subscription didFailUnsubscriptionWithErrorCode:(NSInteger)code message:(nullable NSString *)message

Parameters

subscription

The LSMPNSubscription involved.

code

The error code sent by the Server.

message

The description of the error sent by the Server; it can be nil.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscriptionDidTrigger:

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

For this event to be called the must have a [LSMPNSubscription 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 LSMPNSubscription instance only in case it is subscribed multiple times through [LSLightstreamerClient unsubscribeMPN:] and [LSLightstreamerClient 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.

- (void)mpnSubscriptionDidTrigger:(nonnull LSMPNSubscription *)subscription

Parameters

subscription

The LSMPNSubscription involved.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscription:didChangeStatus:timestamp:

Event handler called when the server notifies that an LSMPNSubscription 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.

- (void)mpnSubscription:(nonnull LSMPNSubscription *)subscription didChangeStatus:(nonnull NSString *)status timestamp:(nonnull NSDate *)timestamp

Parameters

subscription

The LSMPNSubscription involved.

status

The new status of the MPN subscription.

timestamp

The server-side timestamp of the new subscription status.

Declared In

LSMPNSubscriptionDelegate.h

– mpnSubscription:didChangeProperty:

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

- (void)mpnSubscription:(nonnull LSMPNSubscription *)subscription didChangeProperty:(nonnull NSString *)property

Parameters

subscription

The LSMPNSubscription involved.

property

The name of the changed property.

Discussion

Event handler called each time the value of a property of LSMPNSubscription 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 [LSLightstreamerClient subscribeMPN:coalescing:]).

Possible property names are the following:

  • mode

  • group

  • schema

  • adapter

  • notification_format

  • trigger

  • requested_buffer_size

  • requested_max_frequency

  • status_timestamp

Declared In

LSMPNSubscriptionDelegate.h