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    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    * 
    9    *      http://www.apache.org/licenses/LICENSE-2.0
   10    * 
   11    * Unless required by applicable law or agreed to in writing, software
   12    * distributed under the License is distributed on an "AS IS" BASIS,
   13    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   14    * See the License for the specific language governing permissions and
   15    * limitations under the License.
   16    */
   17   
   18   
   19   package org.apache.struts2.jasper.tagplugins.jstl.core;
   20   
   21   import org.apache.struts2.jasper.compiler.tagplugin.TagPlugin;
   22   import org.apache.struts2.jasper.compiler.tagplugin.TagPluginContext;
   23   
   24   
   25   public final class Out implements TagPlugin {
   26   
   27       public void doTag(TagPluginContext ctxt) {
   28   
   29           //these two data member are to indicate 
   30           //whether the corresponding attribute is specified
   31           boolean hasDefault = false, hasEscapeXml = false;
   32           hasDefault = ctxt.isAttributeSpecified("default");
   33           hasEscapeXml = ctxt.isAttributeSpecified("escapeXml");
   34   
   35           //strValName, strEscapeXmlName & strDefName are two variables' name 
   36           //standing for value, escapeXml and default attribute
   37           String strValName = ctxt.getTemporaryVariableName();
   38           String strDefName = ctxt.getTemporaryVariableName();
   39           String strEscapeXmlName = ctxt.getTemporaryVariableName();
   40   
   41           //according to the tag file, the value attribute is mandatory.
   42           ctxt.generateJavaSource("String " + strValName + " = null;");
   43           ctxt.generateJavaSource("if(");
   44           ctxt.generateAttribute("value");
   45           ctxt.generateJavaSource("!=null){");
   46           ctxt.generateJavaSource("    " + strValName + " = (");
   47           ctxt.generateAttribute("value");
   48           ctxt.generateJavaSource(").toString();");
   49           ctxt.generateJavaSource("}");
   50   
   51           //initiate the strDefName with null.
   52           //if the default has been specified, then assign the value to it;
   53           ctxt.generateJavaSource("String " + strDefName + " = null;\n");
   54           if (hasDefault) {
   55               ctxt.generateJavaSource("if(");
   56               ctxt.generateAttribute("default");
   57               ctxt.generateJavaSource(" != null){");
   58               ctxt.generateJavaSource(strDefName + " = (");
   59               ctxt.generateAttribute("default");
   60               ctxt.generateJavaSource(").toString();");
   61               ctxt.generateJavaSource("}");
   62           }
   63   
   64           //initiate the strEscapeXmlName with true;
   65           //if the escapeXml is specified, assign the value to it;
   66           ctxt.generateJavaSource("boolean " + strEscapeXmlName + " = true;");
   67           if (hasEscapeXml) {
   68               ctxt.generateJavaSource(strEscapeXmlName + " = Boolean.parseBoolean((");
   69               ctxt.generateAttribute("default");
   70               ctxt.generateJavaSource(").toString());");
   71           }
   72   
   73           //main part. 
   74           ctxt.generateJavaSource("if(null != " + strValName + "){");
   75           ctxt.generateJavaSource("    if(" + strEscapeXmlName + "){");
   76           ctxt.generateJavaSource("        " + strValName + " = org.apache.struts2.jasper.tagplugins.jstl.Util.escapeXml(" + strValName + ");");
   77           ctxt.generateJavaSource("    }");
   78           ctxt.generateJavaSource("    out.write(" + strValName + ");");
   79           ctxt.generateJavaSource("}else{");
   80           ctxt.generateJavaSource("    if(null != " + strDefName + "){");
   81           ctxt.generateJavaSource("        if(" + strEscapeXmlName + "){");
   82           ctxt.generateJavaSource("            " + strDefName + " = org.apache.struts2.jasper.tagplugins.jstl.Util.escapeXml(" + strDefName + ");");
   83           ctxt.generateJavaSource("        }");
   84           ctxt.generateJavaSource("        out.write(" + strDefName + ");");
   85           ctxt.generateJavaSource("    }else{");
   86           ctxt.generateBody();
   87           ctxt.generateJavaSource("    }");
   88           ctxt.generateJavaSource("}");
   89       }
   90   }

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