Package ch.njol.skript.expressions.base

Class EventValueExpression<T>

java.lang.Object
ch.njol.skript.lang.util.SimpleExpression<T>
ch.njol.skript.expressions.base.EventValueExpression<T>
All Implemented Interfaces:
Debuggable, DefaultExpression<T>, Expression<T>, SyntaxElement
Direct Known Subclasses:
ExprCommandSender, ExprDamageCause, ExprInventoryAction, ExprItem, ExprRegion, ExprSpawnReason, ExprTeleportCause
public class EventValueExpression<T> extends SimpleExpression<T> implements DefaultExpression<T>
A useful class for creating default expressions. It simply returns the event value of the given type.

This class can be used as default expression with new EventValueExpression<T>(T.class) or extended to make it manually placeable in expressions with: 

 class MyExpression extends EventValueExpression<SomeClass> {
        public MyExpression() {
                super(SomeClass.class);
        }
        // ...
 }
See Also:
Classes.registerClass(ClassInfo), ClassInfo.defaultExpression(DefaultExpression), DefaultExpression

  • Constructor Details

    • EventValueExpression

      public EventValueExpression​(Class<? extends T> c)

    • EventValueExpression

      public EventValueExpression​(Class<? extends T> c, @Nullable Changer<? super T> changer)

  • Method Details

    • get

      protected @Nullable T[] get​(org.bukkit.event.Event e)
      Description copied from class: SimpleExpression
      This is the internal method to get an expression's values.
      To get the expression's value from the outside use SimpleExpression.getSingle(Event) or SimpleExpression.getArray(Event).
      Specified by:
      get in class SimpleExpression<T>
      Parameters:
      e - The event
      Returns:
      An array of values for this event. May not contain nulls.

    • init

      public boolean init​(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, SkriptParser.ParseResult parser)
      Description copied from interface: SyntaxElement
      Called just after the constructor.
      Specified by:
      init in interface SyntaxElement
      Parameters:
      exprs - all %expr%s included in the matching pattern in the order they appear in the pattern. If an optional value was left out it will still be included in this list holding the default value of the desired type which usually depends on the event.
      matchedPattern - The index of the pattern which matched
      isDelayed - Whether this expression is used after a delay or not (i.e. if the event has already passed when this expression will be called)
      parser - Additional information about the match.
      Returns:
      Whether this expression was initialised successfully. An error should be printed prior to returning false to specify the cause.
      See Also:
      ParserInstance.isCurrentEvent(Class...)

    • init

      public boolean init()
      Specified by:
      init in interface DefaultExpression<T>

    • getReturnType

      public Class<? extends T> getReturnType()
      Description copied from interface: Expression
      Gets the return type of this expression.
      Specified by:
      getReturnType in interface Expression<T>
      Returns:
      A supertype of any objects returned by Expression.getSingle(Event) and the component type of any arrays returned by Expression.getArray(Event)

    • isSingle

      public boolean isSingle()
      Specified by:
      isSingle in interface Expression<T>
      Returns:
      true if this expression will ever only return one value at most, false if it can return multiple values.

    • toString

      public String toString​(@Nullable org.bukkit.event.Event e, boolean debug)
      Specified by:
      toString in interface Debuggable
      Parameters:
      e - The event to get information to. This is always null if debug == false.
      debug - If true this should print more information, if false this should print what is shown to the end user
      Returns:
      String representation of this object

    • acceptChange

      public @Nullable Class<?>[] acceptChange​(Changer.ChangeMode mode)
      Description copied from interface: Expression
      Tests whether this expression supports the given mode, and if yes what type it expects the delta to be.

      Use Changer.ChangerUtils.acceptsChange(Expression, ChangeMode, Class...) to test whether an expression supports changing, don't directly use this method!

      Please note that if a changer is registered for this expression's returnType this method does not have to be overridden. If you override it though make sure to return super.acceptChange(mode), and to handle the appropriate ChangeMode(s) in Expression.change(Event, Object[], ChangeMode) with super.change(...).

      Unlike Changer.acceptChange(ChangeMode) this method may print errors.

      Specified by:
      acceptChange in interface Expression<T>
      Overrides:
      acceptChange in class SimpleExpression<T>
      Returns:
      An array of types that Expression.change(Event, Object[], ChangeMode) accepts as its delta parameter (which can be arrays to denote that multiple of that type are accepted), or null if the given mode is not supported. For Changer.ChangeMode.DELETE and Changer.ChangeMode.RESET this can return any non-null array to mark them as supported.

    • change

      public void change​(org.bukkit.event.Event e, @Nullable Object[] delta, Changer.ChangeMode mode)
      Description copied from interface: Expression
      Changes the expression's value by the given amount. This will only be called on supported modes and with the desired delta type as returned by Expression.acceptChange(ChangeMode)
      Specified by:
      change in interface Expression<T>
      Overrides:
      change in class SimpleExpression<T>
      delta - An array with one or more instances of one or more of the the classes returned by Expression.acceptChange(ChangeMode) for the given change mode (null for Changer.ChangeMode.DELETE and Changer.ChangeMode.RESET). This can be a Object[], thus casting is not allowed.

    • setTime

      public boolean setTime​(int time)
      Description copied from class: SimpleExpression
      Sets the time of this expression, i.e. whether the returned value represents this expression before or after the event.

      This method will not be called if this expression is guaranteed to be used after a delay (an error will be printed immediately), but will be called if it only can be after a delay (e.g. if the preceding delay is in an if or a loop) as well as if there's no delay involved.

      If this method returns false the expression will be discarded and an error message is printed. Custom error messages must be of ErrorQuality.SEMANTIC_ERROR to be printed (NB: Skript.error(String) always creates semantic errors).

      This implementation sets the time but returns false.

      Specified by:
      setTime in interface Expression<T>
      Overrides:
      setTime in class SimpleExpression<T>
      Parameters:
      time - -1 for past or 1 for future. 0 is never passed to this method as it represents the default state.
      Returns:
      Whether this expression has distinct time states, e.g. a player never changes but a block can. This should be sensitive for the event (using ParserInstance.isCurrentEvent(Class)).
      See Also:
      SimpleExpression.setTime(int, Class, Expression...), SimpleExpression.setTime(int, Expression, Class...)

    • isDefault

      public boolean isDefault()
      Description copied from interface: Expression
      Returns whether this value represents the default value of its type for the event, i.e. it can be replaced with a call to event.getXyz() if one knows the event & value type.

      This method might be removed in the future as it's better to check whether value == event.getXyz() for every value an expression returns.

      Specified by:
      isDefault in interface DefaultExpression<T>
      Specified by:
      isDefault in interface Expression<T>
      Overrides:
      isDefault in class SimpleExpression<T>
      Returns:
      true