xwiki开发者指南-创建新的类属性类型

public class ExternalImageClass extends PropertyClass
{
   /**
     * Default constructor.
     */
   public ExternalImageClass()
   {
       // Specify the default name and pretty name of this XClass property. They can be overwritten from the class
       // editor when adding a property of this type to an XClass.
       super("externalImage", "External Image", null);
   }

   @Override
   public BaseProperty fromString(String value)
   {
        BaseProperty property = newProperty();
       // The stored value can be different than the value set by the user. You can do the needed transformations here.
       // In our case the value is an image URL so we keep it as it is. The reverse transformation, from the stored
       // value to the user friendly value, can be done in the property displayer.
       property.setValue(value);
       return property;
   }

   @Override
   public BaseProperty newProperty()
   {
       // The value of this XClass property is stored as a String. You have to use raw types here like StringProperty
       // because they are mapped to the database. Adding a new raw type implies modifying the Hibernate mapping and is
       // not the subject of this tutorial.
       BaseProperty property = new StringProperty();
        property.setName(getName());
       return property;
   }

   @Override
   public <T extends EntityReference> void mergeProperty(BaseProperty<T> currentProperty,
        BaseProperty<T> previousProperty, BaseProperty<T> newProperty, MergeConfiguration configuration,
        XWikiContext context, MergeResult mergeResult)
   {
       if (!Objects.equals(previousProperty, newProperty)) {
           if (Objects.equals(previousProperty, currentProperty)) {
                currentProperty.setValue(newProperty.getValue());
           } else {
               // Found conflict
               mergeResult.getLog().error("Collision found on property [{}] current has been modified", getName());
           }
       }
   }
}

@Component
// Note that the component hint matches the name of the property class without the "Class" suffix. The reason is that
// the component hint must match the value returned by the #getClassType() method of your property class, which by
// default strips the "Class" suffix from the Java class name of your property class. If you want to use a different
// hint that doesn't follow this naming convention you need to override #getClassType().
@Named("ExternalImage")
@Singleton
public class ExternalImageClassProvider implements PropertyClassProvider
{
   @Override
   public PropertyClassInterface getInstance()
   {
       return new ExternalImageClass();
   }

   @Override
   public PropertyMetaClassInterface getDefinition()
   {
        PropertyMetaClass definition = new PropertyMetaClass();
       // This text will appear in the drop down list of property types to choose from in the class editor.
       definition.setPrettyName("External Image");
        definition.setName(getClass().getAnnotation(Named.class).value());

       // Add a meta property that will allows us to specify a CSS class name for the image HTML element.
       // NOTE: We define meta properties using XClass property types. This means for instance that you can define meta
       // properties of External Image type or whatever XClass property type you create.
       StringClass styleName = new StringClass();
        styleName.setName("styleName");
        styleName.setPrettyName("Style Name");
        definition.safeput(styleName.getName(), styleName);

       // The alternative text is required for a valid image HTML element so we add a meta property for it.
       StringClass placeholder = new StringClass();
        placeholder.setName("placeholder");
        placeholder.setPrettyName("Alternative Text");
        definition.safeput(placeholder.getName(), placeholder);

       // Add more meta properties here.

       return definition;
   }
}