Class PendingCursorOperation

These objects are returned when using find-like functionality on Collection.

They allow chaining of further query-related functions to do things like add a limit to the number of documents you want returned or specify how you want the documents to be sorted and ordered.

You can either call exec() on the object to get an array of documents as 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 observeLocal(), will notify you every time there's an update to a document that matches the query you provided in the preceding find-like call.

A subscription, established by calling subscribe(), will act as a signal to other peers that the device connects to that you would like to receive updates from them about documents that match the query you provided in the preceding find-like call.

Update and remove functionality is also exposed through this object.

Hierarchy

  • PendingCursorOperation

Implements

Properties

collection: Collection

The collection the receiver is operating on.

query: string

The query the receiver is operating with.

queryArgs: QueryArguments

The named arguments for the query.

Methods

  • Evicts all documents that match the query generated by the preceding function chaining.

    Returns

    An array promise containing the IDs of the documents that were evicted.

    Returns Promise<DocumentID[]>

  • Executes the query generated by the preceding function chaining and return the list of matching documents.

    Returns

    An array promise containing documents matching the query generated by the preceding function chaining.

    Returns Promise<Document[]>

  • Limits the number of documents that get returned when querying a collection for matching documents.

    Returns

    A PendingCursorOperation that you can chain further function calls and then either get the matching documents immediately or get updates about them over time.

    Parameters

    • limit: number

      The maximum number of documents that will be returned.

    Returns PendingCursorOperation

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

    The handler block will be called when local changes are made to documents that match the query generated by the chain of operations that precedes the call to observeLocal(). The returned LiveQuery object must be kept in scope for as long as you want the provided handler to be called when an update occurs.

    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, you'll have to create a subscription via subscribe() with the relevant query. The returned LiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Returns

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

    Parameters

    • handler: QueryObservationHandler

      A closure that will be called every time there is a transaction committed to the store that involves modifications to documents matching the query in the collection this method was called on.

    Returns LiveQuery

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

    The handler block will be called when local changes are made to documents that match the query generated by the chain of operations that precedes the call to observeLocalWithNextSignal(). The returned LiveQuery object must be kept in scope for as long as you want the provided handler to be called when an update occurs.

    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, you'll have to create a subscription via subscribe() with the relevant query. The returned LiveQuery object must be kept in scope for as long as you want the provided eventHandler to be called when an update occurs.

    Returns

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

    Parameters

    • handler: QueryObservationHandler

      A closure that will be called every time there is a transaction committed to the store that involves modifications to documents matching the query in the collection that this method was called on.

    Returns LiveQuery

  • Offsets the resulting set of matching documents.

    This is useful if you aren't interested in the first N matching documents for one reason or another. For example, you might already have queried the collection and obtained the first 20 matching documents and so you might want to run the same query as you did previously but ignore the first 20 matching documents, and that is when you would use offset.

    Returns

    A PendingCursorOperation that you can chain further function calls and then either get the matching documents immediately or get updates about them over time.

    Parameters

    • offset: number

      The number of matching documents that you want the eventual resulting set of matching documents to be offset by (and thus not include).

    Returns PendingCursorOperation

  • Removes all documents that match the query generated by the preceding function chaining.

    Returns

    An array promise containing the IDs of the documents that were removed.

    Returns Promise<DocumentID[]>

  • Sorts the documents that match the query provided in the preceding find-like function call.

    Returns

    A PendingCursorOperation that you can chain further function calls and then either get the matching documents immediately or get updates about them over time.

    Parameters

    • propertyPath: string
    • Optional direction: SortDirection

      Specify whether you want the sorting order to be Ascending or Descending.

    Returns PendingCursorOperation

  • Enables you to subscribe to changes that occur in a collection 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 documents that match the query generated by the chain of operations that precedes the call to subscribe().

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

    Returns

    A Subscription object that must be kept in scope for as long as you want to keep receiving updates for documents that match the query specified in the preceding chain.

    Returns Subscription