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     */
019    
020    package org.crsh.shell.impl.command;
021    
022    import org.crsh.command.CommandInvoker;
023    import org.crsh.command.InvocationContext;
024    import org.crsh.command.ScriptException;
025    import org.crsh.io.Filter;
026    import org.crsh.io.ProducerContext;
027    
028    import java.io.IOException;
029    import java.util.Map;
030    
031    /**
032     * A pipe filter that invokes a command through a {@link CommandInvoker}.
033     */
034    class InvokerPipeFilter<C, P> implements Filter<C, P> {
035    
036      /** . */
037      final CommandInvoker<C, P> command;
038    
039      /** . */
040      private ProducerContext<P> context;
041    
042    //  /** . */
043    //  private RenderPrintWriter writer;
044    
045      InvokerPipeFilter(CommandInvoker<C, P> command) {
046        this.command = command;
047      }
048    
049      public void invoke(InvocationContext<P> context) throws ScriptException, IOException {
050        open(context);
051        flush();
052        close();
053      }
054    
055      public void setPiped(boolean piped) {
056        command.setPiped(piped);
057      }
058    
059      public Class<P> getProducedType() {
060        return command.getProducedType();
061      }
062    
063      public Class<C> getConsumedType() {
064        return command.getConsumedType();
065      }
066    
067      public Map<String, Object> getSession() {
068        return context.getSession();
069      }
070    
071      public Map<String, Object> getAttributes() {
072        return context.getAttributes();
073      }
074    
075      public String getProperty(String propertyName) {
076        return context.getProperty(propertyName);
077      }
078    
079      public String readLine(String msg, boolean echo) {
080        return context.readLine(msg, echo);
081      }
082    
083      public int getWidth() {
084        return context.getWidth();
085      }
086    
087      public int getHeight() {
088        return context.getHeight();
089      }
090    
091      public void open(ProducerContext<P> context) {
092    
093        //
094        this.context = context;
095    
096        // Now open command
097        command.open(context);
098      }
099    
100      public void provide(C element) throws IOException {
101        if (command.getConsumedType().isInstance(element)) {
102          command.provide(element);
103        }
104      }
105    
106      public void flush() throws IOException {
107    
108        // First flush the command
109        command.flush();
110    
111        // Flush the next because the command may not call it
112        context.flush();
113      }
114    
115      public void close() throws ScriptException {
116        command.close();
117      }
118    }