ContentSubscription

class kanzi::connect::ContentSubscription : public ContentProvider::Observer, public enable_shared_from_this<ContentSubscription>

A class that represents one content query that was received by the Content Manager.

Public Types

typedef function<void(const string &uri, int reason, int startRow, int endRow)> ContentInvalidationCallback

Callback function for content invalidation.

typedef function<void(const string &uri, ContentDataSharedPtr data)> ContentResultCallback

Callback function for content result.

Public Functions

ContentSubscription(shared_ptr<ContentServiceConcept::Session> session, const string &uri, const string &contentUri, const vector<string> &columns, const string &filter, const string &limit, const string &sort, ContentResultCallback callback, ContentInvalidationCallback invalidationCallback)

Constructor.

Parameters

  • session: Session that initiated the content query.

  • uri: Complete content URI for the query.

  • contentUri: Content table in the encapsulated database.

  • columns: Table columns for the database projection.

  • filter: ‘Where’ clause for filtering output rows.

  • limit: ‘Limit’ clause for selecting output rows.

  • sort: ‘Order by’ clause for sorting output rows.

  • callback: Callback for content result, invoked whenever content subscription is updated.

  • invalidationCallback: Callback for content invalidation notification.

ContentSubscription(shared_ptr<ContentServiceConcept::Session> session, const string &contentUri, ContentQueryArgumentsSharedPtr args, ContentResultCallback callback, ContentInvalidationCallback invalidationCallback)

Builds a content subscription object.

Parameters

  • session: the session

  • args: query arguments

  • callback: for content result, invoked whenever subscription is updated.

  • invalidationCallback: Callback for content invalidation notification.

~ContentSubscription()

Destructor.

const vector<string> &getColumns() const

Retrieve Table columns for the database projection.

Return

Table columns for the database projection.

const string &getContentUri() const

Retrieve content table in the encapsulated database.

Return

Content table in the encapsulated database.

shared_ptr<ContentServiceConcept::Session> getSession() const

Retrieve the session that initiated the query.

Return

Session that initiated the query.

const string &getUri() const

Retrieve complete content URI for the content query.

Return

Content URI for the query.

void onChanged(ContentProvider *provider, const string &uri, bool) override

See ContentProvider::Observer::onChanged.

void onInvalidated(ContentProvider *provider, const string &uri, int reason, int startRow, int endRow) override

Callback to notify invalidation of content provider.

Parameters

  • provider: Content provider that changed.

  • reason: the reason for invalidation. Not currently used.

  • beginRow: inclusive start row of the change. Not currently used.

  • endRow: inclusive end row of the change. Not currently used.

void update(ContentProvider *provider)

Asks the content subscription to update.

Causes it to re-perform the content query.

Parameters

  • provider: Content provider that manages data for this subscription.

void useDiagnosticsTrafficDataSink(DiagnosticsTrafficDataSinkSharedPtr dataSink)

Configures diagnostics data sink to be used by the class.