|
1
52
53 package freemarker.core;
54
55 import java.util.ArrayList  ;
56 import freemarker.template.*;
57
58
62 final class DynamicKeyName extends Expression {
63
64 private final Expression nameExpression;
65 private final Expression target;
66
67 DynamicKeyName(Expression target, Expression nameExpression) {
68 this.target = target;
69 this.nameExpression = nameExpression;
70 }
71
72 TemplateModel _getAsTemplateModel(Environment env) throws TemplateException
73 {
74 TemplateModel targetModel = target.getAsTemplateModel(env);
75 assertNonNull(targetModel, target, env);
76 if (nameExpression instanceof Range) {
77 return dealWithRangeKey(targetModel, (Range) nameExpression, env);
78 }
79 TemplateModel keyModel = nameExpression.getAsTemplateModel(env);
80 if(keyModel == null) {
81 if(env.isClassicCompatible()) {
82 keyModel = TemplateScalarModel.EMPTY_STRING;
83 }
84 else {
85 assertNonNull(keyModel, nameExpression, env);
86 }
87 }
88 if (keyModel instanceof TemplateNumberModel) {
89 int index = EvaluationUtil.getNumber(keyModel, nameExpression, env).intValue();
90 return dealWithNumericalKey(targetModel, index, env);
91 }
92 if (keyModel instanceof TemplateScalarModel) {
93 String key = EvaluationUtil.getString((TemplateScalarModel)keyModel, nameExpression, env);
94 return dealWithStringKey(targetModel, key, env);
95 }
96 throw invalidTypeException(keyModel, nameExpression, env, "number, range, or string");
97 }
98
99
100 private TemplateModel dealWithNumericalKey(TemplateModel targetModel,
101 int index,
102 Environment env)
103 throws TemplateException
104 {
105 if (targetModel instanceof TemplateSequenceModel) {
106 TemplateSequenceModel tsm = (TemplateSequenceModel) targetModel;
107 int size = Integer.MAX_VALUE;
108 try {
109 size = tsm.size();
110 } catch (Exception e) {}
111 return index<size ? tsm.get(index) : null;
112 }
113
114 try
115 {
116 String s = target.getStringValue(env);
117 try {
118 return new SimpleScalar(s.substring(index, index+1));
119 } catch (RuntimeException re) {
120 throw new TemplateException("", re, env);
121 }
122 }
123 catch(NonStringException e)
124 {
125 throw invalidTypeException(targetModel, target, env, "number, sequence, or string");
126 }
127 }
128
129
130 private TemplateModel dealWithStringKey(TemplateModel targetModel,
131 String key,
132 Environment env)
133 throws TemplateException
134 {
135 if(targetModel instanceof TemplateHashModel) {
136 return((TemplateHashModel) targetModel).get(key);
137 }
138 throw invalidTypeException(targetModel, target, env, "hash");
139 }
140
141 private TemplateModel dealWithRangeKey(TemplateModel targetModel,
142 Range range,
143 Environment env)
144 throws TemplateException
145 {
146 int start = EvaluationUtil.getNumber(range.left, env).intValue();
147 int end = EvaluationUtil.getNumber(range.right, env).intValue();
148 if (targetModel instanceof TemplateSequenceModel) {
149 TemplateSequenceModel sequence = (TemplateSequenceModel) targetModel;
150 ArrayList list = new ArrayList (1+Math.abs(start-end));
151 if (start>end) {
152 for (int i = start; i>=end; i--) {
153 list.add(sequence.get(i));
154 }
155 }
156 else {
157 for (int i = start; i<=end; i++) {
158 list.add(sequence.get(i));
159 }
160 }
161 return new SimpleSequence(list);
162 }
163
164 try
165 {
166 String s = target.getStringValue(env);
167 try {
168 return new SimpleScalar(s.substring(start, end+1));
169 } catch (RuntimeException re) {
170 String msg = "Error " + getStartLocation();
171 throw new TemplateException(msg, re, env);
172 }
173 }
174 catch(NonStringException e)
175 {
176 throw invalidTypeException(target.getAsTemplateModel(env), target, env, "number, scalar, or sequence");
177 }
178 }
179
180 public String getCanonicalForm() {
181 return target.getCanonicalForm()
182 + "["
183 + nameExpression.getCanonicalForm()
184 + "]";
185 }
186
187 boolean isLiteral() {
188 return constantValue != null || (target.isLiteral() && nameExpression.isLiteral());
189 }
190
191 Expression _deepClone(String name, Expression subst) {
192 return new DynamicKeyName(target.deepClone(name, subst), nameExpression.deepClone(name, subst));
193 }
194 }
195 |
Popular Tags |
Java API By Example, From Geeks To Geeks.