DITPendingIDSpecificOperation

@interface DITPendingIDSpecificOperation : NSObject

These objects are returned when using findByID functionality on DITCollections.

You can either call exec on the object to get an immediate return value, or you can establish either a live query or a subscription, which both work over time.

A live query, established by calling observe, will notify you every time there’s an update to the document with the ID you provided in the preceding findByID call.

A subscription, established by calling subscribe, will act as a signal to other peers that you would like to receive updates from them about the document with the ID you provided in the preceding findByID call.

Calling observe will generate both a subscription and a live query at the same time.

If you’d like to only observe local changes then you can call observeLocal.

If you want to observe changes in such a way that you can signal when you’re ready for the live query to deliver a new update then you can call observeWithNextSignal or observeLocalWithNextSignal.

Update and remove functionality is also exposed through this object.

  • Execute the find operation to return the document with the matching ID.

    Declaration

    Objective-C

    - (DITDocument *_Nullable)exec;

    Return Value

    The DITDocument with the ID provided in the findByID call or nil if the document was not found.

  • Remove the document with the matching ID.

    Declaration

    Objective-C

    - (BOOL)remove;

    Return Value

    true if the document was found and removed. false if the document wasn’t found and therefore wasn’t removed.

  • Evict the document with the matching ID.

    Declaration

    Objective-C

    - (BOOL)evict;

    Return Value

    true if the document was found and evicted. false if the document wasn’t found and therefore wasn’t evicted.

  • Update the document with the matching ID.

    Declaration

    Objective-C

    - (nonnull NSArray<DITUpdateResult *> *)updateWithBlock:
        (nonnull void (^)(DITMutableDocument *_Nullable))block;

    Parameters

    block

    A block that gets called with the document matching the ID. If found, the document is a DITMutableDocument, so you can call update-related functions on it. If the document is not found then the value provided to the block will be nil.

    Return Value

    A list of DITUpdateResults that describe the updates that were performed on the document.

  • Enables you to subscribe to changes that occur in relation to a document remotely.

    Having a subscription acts as a signal to other peers that you are interested in receiving updates when local or remote changes are made to the relevant document.

    The returned DITSubscription object must be kept in scope for as long as you want to keep receiving updates.

    Declaration

    Objective-C

    - (nonnull DITSubscription *)subscribe;

    Return Value

    A DITSubscription object that must be kept in scope for as long as you want to keep receiving updates for the document.

  • Enables you to listen for changes that occur in relation to a document locally and remotely.

    The eventHandler block will be called when local or remote changes are made to the document referenced by the findByID call that precedes the call to observe.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)observe:
        (nonnull void (^)(DITDocument *_Nullable,
                          DITSingleDocumentLiveQueryEvent *_Nonnull))eventHandler;

    Parameters

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observe was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally and remotely.

    The eventHandler block will be called when local or remote changes are made to the document referenced by the findByID call that precedes the call to observe.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)
        observeWithDeliveryQueue:(nonnull dispatch_queue_t)dispatchQueue
                    eventHandler:
                        (nonnull void (^)(
                            DITDocument *_Nullable,
                            DITSingleDocumentLiveQueryEvent *_Nonnull))eventHandler;

    Parameters

    dispatchQueue

    The dispatch queue that will be used to deliver live query updates. Defaults to the main queue.

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observe was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally and remotely, and to signal when you are ready for the live query to deliver the next event.

    This won’t subscribe to receive changes made remotely by others and so it will only fire updates when a local change is made. If you want to receive remotely performed updates as well then use observe or also call subscribe separately, using another findByID call that references the same document ID.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)observeWithNextSignal:
        (nonnull void (^)(DITDocument *_Nullable,
                          DITSingleDocumentLiveQueryEvent *_Nonnull,
                          DittoSignalNextBlock _Nonnull))eventHandler;

    Parameters

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observeWithNextSignalAndDeliveryQueue was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally and remotely, and to signal when you are ready for the live query to deliver the next event.

    This won’t subscribe to receive changes made remotely by others and so it will only fire updates when a local change is made. If you want to receive remotely performed updates as well then use observe or also call subscribe separately, using another findByID call that references the same document ID.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)
        observeWithNextSignalAndDeliveryQueue:
            (nonnull dispatch_queue_t)dispatchQueue
                                 eventHandler:
                                     (nonnull void (^)(
                                         DITDocument *_Nullable,
                                         DITSingleDocumentLiveQueryEvent *_Nonnull,
                                         DittoSignalNextBlock _Nonnull))
                                         eventHandler;

    Parameters

    dispatchQueue

    The dispatch queue that will be used to deliver live query updates. Defaults to the main queue.

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observeWithNextSignalAndDeliveryQueue was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally.

    This won’t subscribe to receive changes made remotely by others and so it will only fire updates when a local change is made. If you want to receive remotely performed updates as well then use observe or also call subscribe separately, using another findByID call that references the same document ID.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)observeLocal:
        (nonnull void (^)(DITDocument *_Nullable,
                          DITSingleDocumentLiveQueryEvent *_Nonnull))eventHandler;

    Parameters

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observeLocal was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally.

    This won’t subscribe to receive changes made remotely by others and so it will only fire updates when a local change is made. If you want to receive remotely performed updates as well then use observe or also call subscribe separately, using another findByID call that references the same document ID.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)
        observeLocalWithDeliveryQueue:(nonnull dispatch_queue_t)dispatchQueue
                         eventHandler:
                             (nonnull void (^)(DITDocument *_Nullable,
                                               DITSingleDocumentLiveQueryEvent
                                                   *_Nonnull))eventHandler;

    Parameters

    dispatchQueue

    The dispatch queue that will be used to deliver live query updates. Defaults to the main queue.

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observeLocal was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally and to signal when you are ready for the live query to deliver the next event.

    This won’t subscribe to receive changes made remotely by others and so it will only fire updates when a local change is made. If you want to receive remotely performed updates as well then use observe or also call subscribe separately, using another findByID call that references the same document ID.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)
        observeLocalWithNextSignal:(nonnull dispatch_queue_t)dispatchQueue
                      eventHandler:(nonnull void (^)(
                                       DITDocument *_Nullable,
                                       DITSingleDocumentLiveQueryEvent *_Nonnull,
                                       DittoSignalNextBlock _Nonnull))eventHandler;

    Parameters

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observeLocalWithNextSignal was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.

  • Enables you to listen for changes that occur in relation to a document locally and to signal when you are ready for the live query to deliver the next event.

    This won’t subscribe to receive changes made remotely by others and so it will only fire updates when a local change is made. If you want to receive remotely performed updates as well then use observe or also call subscribe separately, using another findByID call that references the same document ID.

    The returned DITLiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Declaration

    Objective-C

    - (nonnull DITLiveQuery *)
        observeLocalWithNextSignalAndDeliveryQueue:
            (nonnull dispatch_queue_t)dispatchQueue
                                      eventHandler:
                                          (nonnull void (^)(
                                              DITDocument *_Nullable,
                                              DITSingleDocumentLiveQueryEvent
                                                  *_Nonnull,
                                              DittoSignalNextBlock _Nonnull))
                                              eventHandler;

    Parameters

    dispatchQueue

    The dispatch queue that will be used to deliver live query updates. Defaults to the main queue.

    eventHandler

    A block that will be called every time there is a transaction committed to the store that involves a modification to the document with the relevant ID in the collection that observeLocalWithNextSignalAndDeliveryQueue was called on.

    Return Value

    A DITLiveQuery object that must be kept in scope for as long as you want to keep receiving updates.