001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019package org.crsh.lang.groovy.closure;
020
021import groovy.lang.Closure;
022import org.crsh.command.CommandContext;
023import org.crsh.shell.impl.command.spi.CommandInvoker;
024
025import java.io.IOException;
026
027/** @author Julien Viet */
028public class ClosureInvoker extends CommandInvoker<Object, Object> {
029
030  /** . */
031  private final Closure closure;
032
033  /** . */
034  private final Class<?> type;
035
036  /** . */
037  private CommandContext<? super Object> consumer;
038
039  public ClosureInvoker(Closure closure) {
040
041    // Resolve the closure consumed type
042    final Class<?> type;
043    Class[] parameterTypes = closure.getParameterTypes();
044    if (parameterTypes != null && parameterTypes.length > 0) {
045      type = parameterTypes[0];
046    } else {
047      type = Object.class;
048    }
049
050    //
051    this.type = type;
052    this.closure = closure;
053  }
054
055  public Class<Object> getProducedType() {
056    return Object.class;
057  }
058  public Class<Object> getConsumedType() {
059    return Object.class;
060  }
061  public void provide(Object element) throws IOException {
062    if (type.isInstance(element)) {
063      Object ret = closure.call(element);
064      if (ret != null) {
065        consumer.provide(ret);
066      }
067    }
068  }
069
070  public void open(CommandContext<? super Object> consumer) {
071    this.consumer = consumer;
072    ClosureDelegate delegate = new ClosureDelegate(consumer, closure.getOwner());
073    closure.setResolveStrategy(Closure.DELEGATE_FIRST);
074    closure.setDelegate(delegate);
075  }
076
077  public void flush() throws IOException {
078    consumer.flush();
079  }
080
081  public void close() {
082    consumer = null;
083  }
084}