Class SnapshotFeed

All Implemented Interfaces:
Result, Receiver

public class SnapshotFeed extends AbsorptionFeed
This class provides streamed implementation of the snapshot() function
  • Constructor Details

  • Method Details

    • getWatch

      public static Trigger getWatch(ItemFeed result, Pattern selection, WatchManager wm, XPathContext context)
      Create a Watch whose effect is to create snapshots of the selected (streamed) nodes and pass them to the supplied feed
      Parameters:
      result - The feed to which the snapshot nodes should be supplied
      selection - defines the nodes to be selected
      wm - The WatchManager that will notify the selected nodes
      context - the XPath evaluation context
      Returns:
      the new Watch
    • makePendingItem

      protected AbsorptionFeed.PendingItem makePendingItem(int sequenceNr, FleetingParentNode node) throws XPathException
      Description copied from class: AbsorptionFeed
      Create a pending item (appropriate to the subclass) containing the data needed to compute the result value for one node in the streamed input sequence
      Specified by:
      makePendingItem in class AbsorptionFeed
      Parameters:
      sequenceNr - the sequence number of this node within a set of nested nodes
      node - the streamed input node
      Returns:
      the data needed to process this node
      Throws:
      XPathException - if a dynamic error is detected at this stage
    • processGroundedItem

      protected Sequence processGroundedItem(Item item)
      Description copied from class: AbsorptionFeed
      Process a grounded item in the input sequence: either a streamed leaf node such as an attribute or text node, or an atomic value, or a non-streamed element or document node injected into the sequence for example by use of the comma operator.
      Specified by:
      processGroundedItem in class AbsorptionFeed
      Parameters:
      item - the grounded item
      Returns:
      the result of processing the grounded item