Module org.apache.wicket.core
Package org.apache.wicket.markup.html.form

Interface IChoiceRenderer<T>

  • Type Parameters:
    T - The model object type
    All Superinterfaces:
    org.apache.wicket.util.io.IClusterable, IDetachable, Serializable
    All Known Implementing Classes:
    ChoiceRenderer, EnumChoiceRenderer
    public interface IChoiceRenderer<T>
extends IDetachable
    Renders one choice. Separates the 'id' values used for internal representation from 'display values' which are the values shown to the user of components that use this renderer.
    Author:
    jcompagner

    • Method Summary

      All Methods Instance Methods Abstract Methods Default Methods 
      Modifier and Type Method Description
      default void detach()
      Override when needed.
      Object getDisplayValue​(T object)
      Get the value for displaying to an end user.
      String getIdValue​(T object, int index)
      This method is called to get the id value of an object (used as the value attribute of a choice element) The id can be extracted from the object like a primary key, or if the list is stable you could just return a toString of the index.
      T getObject​(String id, IModel<? extends List<? extends T>> choices)
      This method is called to get an object back from its id representation.

    • Method Detail

      • getDisplayValue

        Object getDisplayValue​(T object)
        Get the value for displaying to an end user.
        Parameters:
        object - the actual object
        Returns:
        the value meant for displaying to an end user

      • getIdValue

        String getIdValue​(T object,
                  int index)
        This method is called to get the id value of an object (used as the value attribute of a choice element) The id can be extracted from the object like a primary key, or if the list is stable you could just return a toString of the index.

        Note that the given index can be -1 if the object in question is not contained in the available choices.

        Parameters:
        object - The object for which the id should be generated
        index - The index of the object in the choices list.
        Returns:
        String

      • getObject

        T getObject​(String id,
            IModel<? extends List<? extends T>> choices)
        This method is called to get an object back from its id representation. The id may be used to find/load the object in a more efficient way than loading all choices and find the one with the same id in the list
        Parameters:
        id - The id representation of the object
        choices - The list of all rendered choices
        Returns:
        A choice from the list that has this id

      • detach

        default void detach()
        Override when needed.
        Specified by:
        detach in interface IDetachable