TopicControl.MissingTopicNotification (Diffusion)

Enclosing interface:

TopicControl
```
public static interface TopicControl.MissingTopicNotification
```
Notification that a session has made a subscription (or fetch†) request using a selector that does not match any topics.
Processing of the initial request will be halted until proceed is called, at which point the selector will be resolved against the topic tree again.
If after calling proceed the selector still does not match against any topics, no further notifications will be provided.
Should cancel be called, or the notification time out, the request will be discarded. The requesting session will not be notified that their request has been cancelled.
† Missing topic notifications only occur when using the deprecated Topics.fetch(com.pushtechnology.diffusion.client.topics.TopicSelector, com.pushtechnology.diffusion.client.features.Topics.FetchStream) mechanism. The newer Topics.fetchRequest() mechanism does not generate missing topic notifications.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`cancel()` Deprecated. since 6.4 In the future (when the legacy fetch mechanism is removed) the behavior when a subscription selector matches with no topics will be to add the selector to the session's topic selections regardless of whether this is called, and this method will become a no-op and will eventually be removed.
`SessionId`	`getSessionId()` Returns the identity of the session that made the request.
`String`	`getTopicPath()` Returns the topic path derived from the requested topic selector.
`TopicSelector`	`getTopicSelector()` Returns the `TopicSelector` that triggered this notification.
`void`	`proceed()` Instruct the server to complete processing of the request.

- Method Detail
  - getSessionId
```
SessionId getSessionId()
```
    Returns the identity of the session that made the request.
    
    Returns:
    
    the session identifier
  - getTopicPath
```
String getTopicPath()
```
    Returns the topic path derived from the requested topic selector. This method is equivalent to calling getTopicSelector().getPathPrefix().
    
    Returns:
    
    the topic path
  - getTopicSelector
```
TopicSelector getTopicSelector()
```
    Returns the TopicSelector that triggered this notification.
    
    Returns:
    
    the topic selector
    
    Since:
    
    5.1
  - proceed
```
void proceed()
```
    Instruct the server to complete processing of the request.
    This may be called after additional operations (such as adding topics) have been performed, to allow the requested selector to be resolved against the updated topic tree.
    For subscription requests, the topic selector will be added to the session's topic selections. This will cause the session to become subscribed to topics that match the selector if they are added later.
  - cancel
```
@Deprecated
void cancel()
```
    Deprecated. since 6.4
    In the future (when the legacy fetch mechanism is removed) the behavior when a subscription selector matches with no topics will be to add the selector to the session's topic selections regardless of whether this is called, and this method will become a no-op and will eventually be removed.
    
    Cancel the request on the server.
    Calling this will prevent any further processing of the request. For subscription requests, the topic selector will be discarded. The session will not become subscribed to topics that match the selector if they are added later.
    
    Since:
    
    5.1

Interface TopicControl.MissingTopicNotification

Method Summary

Method Detail

getSessionId

getTopicPath

getTopicSelector

proceed

cancel