001/* An actor that outputs a string read from a text file or URL.
002
003 Copyright (c) 2003-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026 */
027package ptolemy.actor.lib.io;
028
029import java.io.BufferedReader;
030
031import ptolemy.actor.TypedIOPort;
032import ptolemy.actor.lib.LimitedFiringSource;
033import ptolemy.data.BooleanToken;
034import ptolemy.data.StringToken;
035import ptolemy.data.expr.FileParameter;
036import ptolemy.data.expr.Parameter;
037import ptolemy.data.expr.SingletonParameter;
038import ptolemy.data.type.BaseType;
039import ptolemy.kernel.CompositeEntity;
040import ptolemy.kernel.util.IllegalActionException;
041import ptolemy.kernel.util.NameDuplicationException;
042
043///////////////////////////////////////////////////////////////////
044//// FileReader
045
046/**
047 This actor reads a file or URL and outputs the entire file
048 as a single string.  The file or URL is specified using any form
049 acceptable to FileParameter.
050
051 @see FileParameter
052 @see LineReader
053
054 @author Yang Zhao (contributor: Edward A. Lee)
055 @version $Id$
056 @since Ptolemy II 3.0
057 @Pt.ProposedRating Yellow (eal)
058 @Pt.AcceptedRating Red (reviewmoderator)
059 */
060public class FileReader extends LimitedFiringSource {
061    /** Construct an actor with a name and a container.
062     *  The container argument must not be null, or a
063     *  NullPointerException will be thrown.
064     *  @param container The container.
065     *  @param name The name of this actor.
066     *  @exception IllegalActionException If the container is incompatible
067     *   with this actor.
068     *  @exception NameDuplicationException If the name coincides with
069     *   an actor already in the container.
070     */
071    public FileReader(CompositeEntity container, String name)
072            throws IllegalActionException, NameDuplicationException {
073        super(container, name);
074
075        output.setTypeEquals(BaseType.STRING);
076
077        fileOrURL = new FileParameter(this, "fileOrURL");
078
079        fileOrURLPort = new TypedIOPort(this, "fileOrURL", true, false);
080        fileOrURLPort.setTypeEquals(BaseType.STRING);
081        new SingletonParameter(fileOrURLPort, "_showName")
082                .setToken(BooleanToken.TRUE);
083
084        newline = new Parameter(this, "newline");
085        newline.setExpression("property(\"line.separator\")");
086
087        // Show the firingCountLimit parameter last.
088        firingCountLimit.moveToLast();
089
090        _attachText("_iconDescription", "<svg>\n" + "<rect x=\"-25\" y=\"-20\" "
091                + "width=\"50\" height=\"40\" " + "style=\"fill:white\"/>\n"
092                + "<polygon points=\"-15,-10 -12,-10 -8,-14 -1,-14 3,-10"
093                + " 15,-10 15,10, -15,10\" " + "style=\"fill:red\"/>\n"
094                + "</svg>\n");
095    }
096
097    ///////////////////////////////////////////////////////////////////
098    ////                         public variables                  ////
099
100    /** The file name or URL from which to read.  This is a string with
101     *  any form accepted by FileParameter.
102     *  @see FileParameter
103     */
104    public FileParameter fileOrURL;
105
106    /** An input port for optionally providing a file name. This has
107     *  type string.
108     */
109    public TypedIOPort fileOrURLPort;
110
111    /** The end of line character(s).  The default value is the value
112     *  of the line.separator property
113     */
114    public Parameter newline;
115
116    ///////////////////////////////////////////////////////////////////
117    ////                         public methods                    ////
118
119    /** Output the data read from the file or URL as a string.
120     *  @exception IllegalActionException If there is no director or
121     *   if reading the file triggers an exception.
122     */
123    @Override
124    public void fire() throws IllegalActionException {
125        super.fire();
126
127        // If the fileOrURL input port is connected and has data, then
128        // get the file name from there.
129        if (fileOrURLPort.isOutsideConnected()) {
130            if (fileOrURLPort.hasToken(0)) {
131                String name = ((StringToken) fileOrURLPort.get(0))
132                        .stringValue();
133
134                // Using setExpression() rather than setToken() allows
135                // the string to refer to variables defined in the
136                // scope of this actor.
137                fileOrURL.setExpression(name);
138                fileOrURL.validate();
139            }
140        }
141
142        BufferedReader reader = null;
143
144        StringBuffer lineBuffer = new StringBuffer();
145        try {
146            reader = fileOrURL.openForReading();
147
148            String newlineValue = ((StringToken) newline.getToken())
149                    .stringValue();
150            while (true) {
151                String line = reader.readLine();
152
153                if (line == null) {
154                    break;
155                }
156
157                lineBuffer = lineBuffer.append(line);
158                lineBuffer = lineBuffer.append(newlineValue);
159            }
160        } catch (Throwable throwable) {
161            throw new IllegalActionException(this, throwable,
162                    "Failed to read '" + fileOrURL + "'");
163        } finally {
164            if (fileOrURL != null) {
165                fileOrURL.close();
166            }
167        }
168        _handleFileData(lineBuffer.toString());
169    }
170
171    ///////////////////////////////////////////////////////////////////
172    ////                         protected methods                 ////
173
174    /** Send the specified string to the output.
175     *  @param fileContents The contents of the file or URL that was read.
176     *  @exception IllegalActionException If sending the data fails.
177     */
178    protected void _handleFileData(String fileContents)
179            throws IllegalActionException {
180        output.broadcast(new StringToken(fileContents));
181    }
182}