Package org.apache.tapestry5.internal

## Class EmptyEventContext

- java.lang.Object
- - org.apache.tapestry5.internal.EmptyEventContext

- All Implemented Interfaces:
    `EventContext`

      public class EmptyEventContext
      extends Object
      implements EventContext

  Placeholder used when no context is available.

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `EmptyEventContext()` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `<T> T` | `get​(Class<T> desiredType, int index)` | This should never be called because the count is always zero.
    `int` | `getCount()` | Always returns zero.
    `boolean` | `isEmpty()` | Returns `true` if this context contains no elements.
    `String[]` | `toStrings()` | Extracts the value of each context value as a string.
    `<T> Optional<T>` | `tryGet​(Class<T> desiredType, int index)` | Tries to extract a parameter value and coerces or decodes it to the desired type.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### EmptyEventContext

          public EmptyEventContext()

  - ### Method Detail

    - #### 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.isEmpty()` if index is out of bounds, or the value can't be converted.