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/*
 Copyright (c) 2011, The Staccato-Commons Team

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; version 3 of the License.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Lesser General Public License for more details.
 */
package net.sf.staccatocommons.dynamic;

import net.sf.staccatocommons.dynamic.internal.NullDynamic;
import net.sf.staccatocommons.dynamic.internal.ReflectiveDynamic;
import net.sf.staccatocommons.restrictions.Constant;
import net.sf.staccatocommons.restrictions.check.NonNull;

/**
 * Class methods for creating simple {@link Dynamic}s
 * 
 * @author flbulgarelli
 */
public class Dynamics {

  private static final NullDynamic NULL = new NullDynamic();

  /**
   * Answers a new {@link Dynamic} wrapper for the given {@code object}, that
   * uses reflection to invoke methods, and property descriptors to get
   * 
   * @param object
   * @return a new {@link Dynamic}
   */
  @NonNull
  public static Dynamic from(@NonNull Object object) {
    return new ReflectiveDynamic(object);
  }

  /**
   * Answers a new {@link Dynamic} wrapper for the given {@code object}, if it
   * is not null, or null_()
   * 
   * otherwise
   * 
   * @param object
   * @return a new {@link Dynamic}, or {@link #null_()}, if the object is null
   */
  @NonNull
  public static Dynamic nullSafeFrom(Object object) {
    return object != null ? from(object) : Dynamics.null_();
  }

  /**
   * Answers the null Dynamic, that is, a {@link Dynamic} that understands all
   * messages, by doing nothing and returning null.
   * 
   * Its {@link Dynamic#value()} is null
   * 
   * @return the null dynamic
   */
  @Constant
  public static Dynamic null_() {
    return NULL;
  }

  /**
   * Answer a new {@link Dynamic} that wraps a new instance of a class for its
   * given classname
   * 
   * @param classname
   *          the class name
   * @return a new Dynamic wrapper for a new instance of the given class
   * @throws InstantiationFailedException
   *           if class can not be instantiated
   */
  public static Dynamic fromClassName(@NonNull String classname) {
    try {
      return fromClass(Class.forName(classname));
    } catch (Exception e) {
      throw new InstantiationFailedException(e);
    }
  }

  /**
   * Answer a new {@link Dynamic} that wraps a new instance of the given class
   * 
   * @param clazz
   *          the class to instantiate
   * @return a new Dynamic wrapper for a new instance of the given class
   * @throws InstantiationFailedException
   *           if class can not be instantiated
   */
  @NonNull
  public static Dynamic fromClass(@NonNull Class clazz) {
    try {
      return from(clazz.newInstance());
    } catch (Exception e) {
      throw new InstantiationFailedException(e);
    }
  }

}