1 /* 2 * Copyright (C) 2010 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.clearsilver.jsilver.values; 18 19 import com.google.clearsilver.jsilver.autoescape.EscapeMode; 20 import com.google.clearsilver.jsilver.data.Data; 21 import com.google.clearsilver.jsilver.data.DataContext; 22 import com.google.clearsilver.jsilver.data.TypeConverter; 23 24 /** 25 * A value linked to a variable reference. When this value is evaluated in an expression a Data 26 * object will be fetched from the provided DataContext and and its value returned or {@code null} 27 * if there is no Data object associated with the given name. 28 * 29 * @see Value 30 * @see Data 31 */ 32 public class VariableValue extends VariantValue { 33 // TODO: Make this non-public and come up with a smarter way 34 // for it to be used elsewhere without having to be used in a cast. 35 36 private final String name; 37 private final DataContext dataContext; 38 39 private boolean gotRef = false; 40 private Data reference; 41 VariableValue(String name, DataContext dataContext)42 public VariableValue(String name, DataContext dataContext) { 43 // VariableValues always have partiallyEscaped=false since they represent 44 // a Data object, not a compound expression containing escaping functions. 45 // We override getEscapeMode() to return the Data object's escape mode, 46 // so the mode we pass here is just ignored. 47 super(EscapeMode.ESCAPE_NONE, false); 48 this.dataContext = dataContext; 49 this.name = name; 50 } 51 getName()52 public String getName() { 53 return name; 54 } 55 getReference()56 public Data getReference() { 57 if (!gotRef) { 58 reference = dataContext.findVariable(name, false); 59 gotRef = true; 60 } 61 return reference; 62 } 63 64 @Override value()65 protected String value() { 66 Data data = getReference(); 67 return data == null ? null : data.getValue(); 68 } 69 70 @Override exists()71 public boolean exists() { 72 return TypeConverter.exists(getReference()); 73 } 74 75 // Note we are not overriding asString as we want that to return the value 76 // of the node located at this address. 77 @Override toString()78 public String toString() { 79 return name; 80 } 81 82 @Override getEscapeMode()83 public EscapeMode getEscapeMode() { 84 Data data = getReference(); 85 if (data == null) { 86 return super.getEscapeMode(); 87 } 88 return data.getEscapeMode(); 89 } 90 91 } 92