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1
45 package groovy.text;
46
47 import groovy.lang.*;
48
49 import java.io.IOException  ;
50 import java.io.PrintWriter ;
51 import java.io.Reader ;
52 import java.io.StringWriter ;
53 import java.io.Writer ;
54 import java.security.AccessController ;
55 import java.security.PrivilegedAction ;
56 import java.util.Map ;
57
58 import org.codehaus.groovy.control.CompilationFailedException;
59
60
61
65 public class GStringTemplateEngine extends TemplateEngine {
66
69 public Template createTemplate(final Reader reader) throws CompilationFailedException, ClassNotFoundException , IOException {
70 return new GStringTemplate(reader);
71 }
72
73 private static class GStringTemplate implements Template {
74 final Closure template;
75
76
95 public GStringTemplate(final Reader reader) throws CompilationFailedException, ClassNotFoundException , IOException {
96 final StringBuffer templateExpressions = new StringBuffer ("package groovy.tmp.templates\nclass C { getTemplate() { { |out| out << \"");
97 boolean writingString = true;
98
99 while(true) {
100 int c = reader.read();
101
102 if (c == -1) break;
103
104 if (c == '<') {
105 c = reader.read();
106
107 if (c == '%') {
108 c = reader.read();
109
110 if (c == '=') {
111 parseExpression(reader, writingString, templateExpressions);
112 writingString = true;
113 continue;
114 } else {
115 parseSection(reader, writingString, templateExpressions);
116 writingString = false;
117 continue;
118 }
119 } else {
120 appendCharacter('<', templateExpressions, writingString);
121 writingString = true;
122 }
123 } else if (c == '"') {
124 appendCharacter('\\', templateExpressions, writingString);
125 writingString = true;
126 }
127
128 appendCharacter((char)c, templateExpressions, writingString);
129 writingString = true;
130 }
131
132 if (writingString) {
133 templateExpressions.append("\"");
134 }
135
136 templateExpressions.append("}.asWritable()}}");
137
138
140 final ClassLoader parentLoader = getClass().getClassLoader();
141 final GroovyClassLoader loader =
142 (GroovyClassLoader) AccessController.doPrivileged(new PrivilegedAction () {
143 public Object run() {
144 return new GroovyClassLoader(parentLoader);
145 }
146 });
147 final Class groovyClass = loader.parseClass(new GroovyCodeSource(templateExpressions.toString(), "C", "x"));
148
149 try {
150 final GroovyObject object = (GroovyObject) groovyClass.newInstance();
151
152 this.template = (Closure)object.invokeMethod("getTemplate", null);
153 } catch (InstantiationException e) {
154 throw new ClassNotFoundException (e.getMessage());
155 } catch (IllegalAccessException e) {
156 throw new ClassNotFoundException (e.getMessage());
157 }
158 }
159
160 private static void appendCharacter(final char c,
161 final StringBuffer templateExpressions,
162 final boolean writingString)
163 {
164 if (!writingString) {
165 templateExpressions.append("out << \"");
166 }
167
168 templateExpressions.append(c);
169 }
170
171
181 private static void parseSection(final Reader reader,
182 final boolean writingString,
183 final StringBuffer templateExpressions)
184 throws IOException
185 {
186 if (writingString) {
187 templateExpressions.append("\"; ");
188 }
189
190 while (true) {
191 int c = reader.read();
192
193 if (c == -1) break;
194
195 if (c =='%') {
196 c = reader.read();
197
198 if (c == '>') break;
199 }
200
201 templateExpressions.append((char)c);
202 }
203
204 templateExpressions.append("; ");
205 }
206
207
215 private static void parseExpression(final Reader reader,
216 final boolean writingString,
217 final StringBuffer templateExpressions)
218 throws IOException
219 {
220 if (!writingString) {
221 templateExpressions.append("out << \"");
222 }
223
224 templateExpressions.append("${");
225
226 while (true) {
227 int c = reader.read();
228
229 if (c == -1) break;
230
231 if (c =='%') {
232 c = reader.read();
233
234 if (c == '>') break;
235 }
236
237 templateExpressions.append((char)c);
238 }
239
240 templateExpressions.append('}');
241 }
242
243 public Writable make() {
244 return make(null);
245 }
246
247 public Writable make(final Map map) {
248 final Closure delegatedClosure = (Closure)this.template.clone();
249
250 delegatedClosure.setDelegate(new Binding(map));
251
252 return new Writable() {
253
256 public Writer writeTo(final Writer writer) throws IOException {
257 delegatedClosure.call(new Object [] {new PrintWriter (writer)});
258
259 return writer;
260 }
261
262
265 public String toString() {
266 final StringWriter stringWriter = new StringWriter ();
267
268 try {
269 writeTo(stringWriter);
270
271 return stringWriter.toString();
272 } catch (final IOException e) {
273 return e.toString();
274 }
275 }
276
277 };
278 }
279 }
280 }
281 |
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