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    1   /*
    2    * $Id: CallbackWriter.java 471756 2006-11-06 15:01:43Z husted $
    3    *
    4    * Licensed to the Apache Software Foundation (ASF) under one
    5    * or more contributor license agreements.  See the NOTICE file
    6    * distributed with this work for additional information
    7    * regarding copyright ownership.  The ASF licenses this file
    8    * to you under the Apache License, Version 2.0 (the
    9    * "License"); you may not use this file except in compliance
    10   * with the License.  You may obtain a copy of the License at
    11   *
    12   *  http://www.apache.org/licenses/LICENSE-2.0
    13   *
    14   * Unless required by applicable law or agreed to in writing,
    15   * software distributed under the License is distributed on an
    16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    17   * KIND, either express or implied.  See the License for the
    18   * specific language governing permissions and limitations
    19   * under the License.
    20   */
    21  package org.apache.struts2.views.freemarker.tags;
    22
    23  import java.io.IOException;
    24  import java.io.StringWriter;
    25  import java.io.Writer;
    26
    27  import org.apache.struts2.components.Component;
    28
    29  import freemarker.template.TemplateModelException;
    30  import freemarker.template.TransformControl;
    31
    32  /***
    33   */
    34  public class CallbackWriter extends Writer implements TransformControl {
    35      private Component bean;
    36      private Writer writer;
    37      private StringWriter body;
    38      private boolean afterBody = false;
    39
    40      public CallbackWriter(Component bean, Writer writer) {
    41          this.bean = bean;
    42          this.writer = writer;
    43
    44          if (bean.usesBody()) {
    45              this.body = new StringWriter();
    46          }
    47      }
    48
    49      public void close() throws IOException {
    50          if (bean.usesBody()) {
    51              body.close();
    52          }
    53      }
    54
    55      public void flush() throws IOException {
    56          writer.flush();
    57
    58          if (bean.usesBody()) {
    59              body.flush();
    60          }
    61      }
    62
    63      public void write(char cbuf[], int off, int len) throws IOException {
    64          if (bean.usesBody() && !afterBody) {
    65              body.write(cbuf, off, len);
    66          } else {
    67              writer.write(cbuf, off, len);
    68          }
    69      }
    70
    71      public int onStart() throws TemplateModelException, IOException {
    72          boolean result = bean.start(this);
    73
    74          if (result) {
    75              return EVALUATE_BODY;
    76          } else {
    77              return SKIP_BODY;
    78          }
    79      }
    80
    81      public int afterBody() throws TemplateModelException, IOException {
    82          afterBody = true;
    83          boolean result = bean.end(this, bean.usesBody() ? body.toString() : "");
    84
    85          if (result) {
    86              return REPEAT_EVALUATION;
    87          } else {
    88              return END_EVALUATION;
    89          }
    90      }
    91
    92      public void onError(Throwable throwable) throws Throwable {
    93          throw throwable;
    94      }
    95
    96      public Component getBean() {
    97          return bean;
    98      }
    99  }