Class EmptyEventContext

java.lang.Object
org.apache.tapestry5.internal.EmptyEventContext
All Implemented Interfaces:
Serializable, EventContext

public class EmptyEventContext extends Object implements EventContext, Serializable
Placeholder used when no context is available.
See Also:
  • Constructor Details

  • Method Details

    • getCount

      public int getCount()
      Always returns zero.
      Specified by:
      getCount in interface EventContext
    • get

      public <T> T get(Class<T> desiredType, int index)
      This should never be called because the count is always zero.
      Specified by:
      get in interface EventContext
      Parameters:
      desiredType - the type of value required
      index - identifies which parameter value to extract
      Returns:
      the value extracted and converted or coerced
    • toStrings

      public String[] toStrings()
      Description copied from interface: EventContext
      Extracts the value of each context value as a string.
      Specified by:
      toStrings in interface EventContext
      Returns:
      context values
    • isEmpty

      public boolean isEmpty()
      Description copied from interface: EventContext
      Returns true if this context contains no elements.
      Specified by:
      isEmpty in interface EventContext
    • tryGet

      public <T> Optional<T> tryGet(Class<T> desiredType, int index)
      Description copied from interface: EventContext
      Tries to extract a parameter value and coerces or decodes it to the desired type.
      Specified by:
      tryGet in interface EventContext
      Parameters:
      desiredType - the type of value required
      index - identifies which parameter value to extract
      Returns:
      the value extracted and converted or coerced, wrapped in an Optional, or Optional.empty() if index is out of bounds, or the value can't be converted.