package org.argeo.api;
   
   import java.util.function.BiFunction;
   
   /**
    * Stateless UI part creator. Takes a parent view (V) and a model context (M) in
    * order to create a view part (W) which can then be further configured. Such
    * object can be used as services and reference other part of the model which
    * are relevant for all created UI part.
   */
  @FunctionalInterface
  public interface MvcProvider<V, M, W> extends BiFunction<V, M, W> {
  	W createUiPart(V parent, M context);
  	
  	/**
  	 * Whether this parent view is supported.
  	 * 
  	 * @return true by default.
  	 */
  	default boolean isViewSupported(V parent) {
  		return true;
  	}
  
  	/**
  	 * Whether this context is supported.
  	 * 
  	 * @return true by default.
  	 */
  	default boolean isModelSupported(M context) {
  		return true;
  	}
  
  	default W apply(V parent, M context) {
  		if (!isViewSupported(parent))
  			throw new IllegalArgumentException("Parent view " + parent + "is not supported.");
  		if (!isModelSupported(context))
  			throw new IllegalArgumentException("Model context " + context + "is not supported.");
  		return createUiPart(parent, context);
  	}
  
  	default W createUiPart(V parent) {
  		return createUiPart(parent, null);
  	}
  }