Package com.saxonica.ee.stream.adjunct

Class FirstItemExpressionAdjunct

java.lang.Object
com.saxonica.ee.stream.adjunct.StreamingAdjunct
com.saxonica.ee.stream.adjunct.TransmissionAdjunct
com.saxonica.ee.stream.adjunct.FilteringAdjunct
com.saxonica.ee.stream.adjunct.FirstItemExpressionAdjunct
All Implemented Interfaces:
FeedMaker
public class FirstItemExpressionAdjunct extends FilteringAdjunct implements FeedMaker
Generate streaming code for a first item expression (when not part of a Watch).

  • Constructor Details

    • FirstItemExpressionAdjunct

      public FirstItemExpressionAdjunct()

  • Method Details

    • computeStreamability

      public PostureAndSweep computeStreamability(ContextItemStaticInfoEE contextInfo, List<String> reasons)
      Get the posture and sweep of this expression as defined in the W3C streamability specifications. This provides an assessment of stylesheet code against the W3C criteria for guaranteed streamability, and is implemented to allow these criteria to be tested. It is not the case that all expression that emerge as streamable from this analysis are currently capable of being streamed by Saxon
      Overrides:
      computeStreamability in class StreamingAdjunct
      Parameters:
      contextInfo - Information about the context item type and posture
      reasons - the caller may supply a list, in which case the implementation may add to this
      Returns:
      the posture and sweep of the expression

    • makeFilter

      public FilteringFeed.Filter makeFilter(XPathContext context, ItemFeed out) throws XPathException
      Make a filter for the event stream
      Specified by:
      makeFilter in class FilteringAdjunct
      Parameters:
      context - the XPath dynamic context
      out - destination for the output of this filter
      Returns:
      a filter that can be added to the event stream
      Throws:
      XPathException - if a dynamic evaluation error occurs