##### Coverage Report - org.webmacro.util.WMEval

Classes in this File | Line Coverage | Branch Coverage | Complexity
WMEval |
0% | 0/83
0% | 0/10
| 1.5416666666666667;1.542

1 |  |
     /*
2 |  |
      * Copyright (C) 1998-2000 Semiotek Inc.  All Rights Reserved.
3 |  |
      *
4 |  |
      * Redistribution and use in source and binary forms, with or without
5 |  |
      * modification, are permitted under the terms of either of the following
6 |  |
      * Open Source licenses:
7 |  |
      *
8 |  |
      * The GNU General Public License, version 2, or any later version, as
9 |  |
      * published by the Free Software Foundation
10 |  |
      * (http://www.fsf.org/copyleft/gpl.html);
11 |  |
      *
12 |  |
      *  or
13 |  |
      *
14 |  |
      * The Semiotek Public License (http://webmacro.org/LICENSE.)
15 |  |
      *
16 |  |
      * This software is provided "as is", with NO WARRANTY, not even the
17 |  |
      * implied warranties of fitness to purpose, or merchantability. You
18 |  |
      * assume all risks and liabilities associated with its use.
19 |  |
      *
20 |  |
      * See www.webmacro.org for more information on the WebMacro project.
21 |  |
      */
22 |  |
23 |  |
     package org.webmacro.util;
24 |  |
25 |  |
     import java.io.FileOutputStream;
26 |  |
     import java.io.InputStream;
27 |  |
     import java.io.OutputStream;
28 |  |
29 |  |
     import javax.servlet.Servlet;
30 |  |
     import javax.servlet.ServletException;
31 |  |
     import javax.servlet.http.HttpServletRequest;
32 |  |
     import javax.servlet.http.HttpServletResponse;
33 |  |
34 |  |
     import org.slf4j.Logger;
35 |  |
     import org.slf4j.LoggerFactory;
36 |  |
37 |  |
     import org.webmacro.Context;
38 |  |
     import org.webmacro.Template;
39 |  |
     import org.webmacro.WM;
40 |  |
     import org.webmacro.WMConstants;
41 |  |
     import org.webmacro.WebMacro;
42 |  |
     import org.webmacro.engine.StreamTemplate;
43 |  |
     import org.webmacro.resource.AbstractTemplateLoader;
44 |  |
     import org.webmacro.servlet.WMServlet;
45 |  |
     import org.webmacro.servlet.WebContext;
46 |  |
47 |  |
48 |  |
     /**
49 |  |
      * WMEval encapsulates an instance of WebMacro for reuse in any java application.
50 |  |
      * <p>
51 |  |
      * It's main benefits are a number of convenience methods for evaluating a template
52 |  |
      * and directing output either to a supplied output stream or to a file.
53 |  |
      * <p>
54 |  |
      * It can parse a single template stream and then evaluate that template
55 |  |
      * over a number of different contexts. And, it can maintain a single context
56 |  |
      * and evaluate different templates over the same context. Each time a context
57 |  |
      * or a template is provided, it is retained as state.
58 |  |
      * <p>
59 |  |
      * The context can therefore be preserved over multiple "writes" of different
60 |  |
      * templates.
61 |  |
      * <p>
62 |  |
      * The template stream can be any text stream but is often a rule stream containing
63 |  |
      * wm script directives.
64 |  |
      * <p>
65 |  |
      * This helper class is useful for evaluating WebMacro templates for which
66 |  |
      * flexibility in managing the evaluation options is key.
67 |  |
      *
68 |  |
      * @author Lane Sharman
69 |  |
      * @version 3.0
70 |  |
      */
71 |  |
     public class WMEval
72 |  |
     {
73 |  |
74 |  |
         //-------public members-----
75 |  |
76 |  |
         //-------private and protected members-----
77 |  |
         private WebMacro wm;
78 |  |
79 | 0 |
         static Logger _log =  LoggerFactory.getLogger(WMEval.class);
80 |  |
81 |  |
         private Template currentTemplate;
82 |  |
83 |  |
         //private OutputStream out = System.out;
84 |  |
85 |  |
         private Context context;
86 |  |
87 |  |
         /**
88 |  |
          * If an output file is not specified as an argument, it
89 |  |
          * must be found in the context under this key.
90 |  |
          */
91 |  |
         public static final String outputContextKey = "OutputFileName";
92 |  |
93 |  |
         //-------constructor(s)-----
94 |  |
         /**
95 |  |
          * Constructor.
96 |  |
          * Build a WebMacro environment for currentTemplate execution.
97 |  |
          */
98 |  |
         public WMEval()
99 | 0 |
         {
100 |  |
             try {
101 | 0 |
                 wm = new WM();
102 | 0 |
                 init();
103 | 0 |
             } catch (Exception e) {
104 | 0 |
                 throw new IllegalStateException(e);
105 | 0 |
             }
106 | 0 |
         }
107 |  |
108 |  |
         /**
109 |  |
          * Build a WebMacro environment to evaluate a template given it's name.
110 |  |
          */
111 |  |
         public WMEval(String templateName)
112 | 0 |
         {
113 |  |
             try {
114 | 0 |
                 wm = new WM();
115 | 0 |
                 init();
116 | 0 |
                 parseLocalTemplate(templateName);
117 | 0 |
             } catch (Exception e) {
118 | 0 |
                 throw new IllegalStateException(e);
119 | 0 |
             }
120 | 0 |
         }
121 |  |
122 |  |
         /**
123 |  |
          * The constructor for WebMacro decorator in a servlet context.
124 |  |
          * Build a WebMacro environment for currentTemplate execution.
125 |  |
          */
126 |  |
         public WMEval(Servlet servlet)
127 | 0 |
         {
128 |  |
             try {
129 | 0 |
                 if (servlet == null)
130 | 0 |
                     wm = new WM();
131 |  |
                 else
132 | 0 |
                     wm = new WM(servlet);
133 | 0 |
                 init();
134 | 0 |
             } catch (Exception e) {
135 | 0 |
                 throw new IllegalStateException(e);
136 | 0 |
             }
137 | 0 |
         }
138 |  |
139 |  |
         private void init() {
140 | 0 |
             context = wm.getContext();
141 | 0 |
         }
142 |  |
         /**
143 |  |
          * Return the settings associated with this WebMacro instance.
144 |  |
          */
145 |  |
         public Settings getSettings ()
146 |  |
         {
147 | 0 |
             return wm.getBroker().getSettings();
148 |  |
         }
149 |  |
150 |  |
         /**
151 |  |
          * Return the log associated with this instance of WMEval.
152 |  |
          */
153 |  |
         public Logger getLog ()
154 |  |
         {
155 | 0 |
             return _log;
156 |  |
         }
157 |  |
158 |  |
         //-------public initializers/destroyers-----
159 |  |
         /**
160 |  |
          * Initializes WMEval so that it can perform currentTemplate evaluation
161 |  |
          * on multiple contexts. Init parses the currentTemplate supplied.
162 |  |
          * <p>
163 |  |
          * The argument to init() is the currentTemplate as a stream allowing the
164 |  |
          * currentTemplate to come from pretty much anywhere such as a url,
165 |  |
          * a file, or a db field.
166 |  |
          * <p>
167 |  |
          * Care must be given to the fact that in parsing the currentTemplate,
168 |  |
          * the current vm is able to resolve locations of other currentTemplates
169 |  |
          * referenced within the supplied currentTemplate.
170 |  |
          * <p>
171 |  |
          * Note, once this is complete, the parsed currentTemplate can be applied
172 |  |
          * to successive new object contexts. In other words, the application context
173 |  |
          * can assert new objects for currentTemplate application and remove others.
174 |  |
          *
175 |  |
          * @param template The stream containing the top-level, unparsed currentTemplate.
176 |  |
          *
177 |  |
          */
178 |  |
         public Template init (InputStream template) throws Exception
179 |  |
         {
180 | 0 |
             Template t = new StreamTemplate(wm.getBroker(),
181 |  |
                     template);
182 | 0 |
             t.parse();
183 | 0 |
             this.currentTemplate = t;
184 | 0 |
             return t;
185 |  |
         }
186 |  |
187 |  |
         public void error (String msg, Exception e)
188 |  |
         {
189 | 0 |
             _log.error(msg, e);
190 | 0 |
         }
191 |  |
192 |  |
         /**
193 |  |
          * Provides for a new context to be established.
194 |  |
          */
195 |  |
         public Context getNewContext ()
196 |  |
         {
197 | 0 |
             Context c = wm.getContext();
198 | 0 |
             this.context = c;
199 | 0 |
             return c;
200 |  |
         }
201 |  |
202 |  |
         public WebContext getNewContext (HttpServletRequest req,
203 |  |
                 HttpServletResponse resp)
204 |  |
         {
205 | 0 |
             WebContext c = wm.getWebContext(req, resp);
206 | 0 |
             this.context = c;
207 | 0 |
             return c;
208 |  |
         }
209 |  |
210 |  |
         /**
211 |  |
          * Gets the current context.
212 |  |
          */
213 |  |
         public Context getCurrentContext ()
214 |  |
         {
215 | 0 |
             return this.context;
216 |  |
         }
217 |  |
218 |  |
         /**
219 |  |
          * Gets the current template.
220 |  |
          */
221 |  |
         public Template getCurrentTemplate ()
222 |  |
         {
223 | 0 |
             return this.currentTemplate;
224 |  |
         }
225 |  |
226 |  |
         /**
227 |  |
          * A convenience method to find and parse a template in the local template path.
228 |  |
          * FIXME Do not set currentTemplate here
229 |  |
          */
230 |  |
         public Template parseLocalTemplate (String templateName) throws Exception
231 |  |
         {
232 | 0 |
             Template t = wm.getTemplate(templateName);
233 | 0 |
             this.currentTemplate = t;
234 | 0 |
             return t;
235 |  |
         }
236 |  |
237 |  |
         /**
238 |  |
          * Supplies the parsed currentTemplate directly.
239 |  |
          * @param parsedTemplate The currentTemplate parsed possibly from a previous run.
240 |  |
          */
241 |  |
         public void setCurrentTemplate (Template parsedTemplate)
242 |  |
         {
243 | 0 |
             this.currentTemplate = parsedTemplate;
244 | 0 |
         }
245 |  |
246 |  |
         /**
247 |  |
          * Supplies a context to be  parsed currentTemplate directly.
248 |  |
          * @param c The context to be used for the evaluation.
249 |  |
          */
250 |  |
         public void setCurrentContext (Context c)
251 |  |
         {
252 | 0 |
             this.context = c;
253 | 0 |
         }
254 |  |
255 |  |
         /**
256 |  |
          * Sets the output stream to be different than the default, System.out.
257 |  |
          * @param out The new output stream for any output during currentTemplate evaluation.
258 |  |
          */
259 |  |
         //public void setOutputStream (OutputStream out)
260 |  |
         //{
261 |  |
         //    this.out = out;
262 |  |
         //}
263 |  |
264 |  |
         /**
265 |  |
          * Evaluates the context of this instance and the instance's
266 |  |
          * current template and current output stream using UTF8.
267 |  |
          */
268 |  |
         public String eval () throws Exception
269 |  |
         {
270 | 0 |
             return eval(context, currentTemplate);
271 |  |
         }
272 |  |
273 |  |
         /**
274 |  |
          * Evaluate the context supplied against the current template.
275 |  |
          * @param context The WebMacro context.
276 |  |
          */
277 |  |
         public String eval (Context context) throws Exception
278 |  |
         {
279 | 0 |
             return eval(context, currentTemplate);
280 |  |
         }
281 |  |
282 |  |
         /**
283 |  |
          * Evaluate the supplied template against the supplied context and
284 |  |
          * return the result as a string.
285 |  |
          */
286 |  |
         public String eval (Context context, Template template) throws Exception
287 |  |
         {
288 | 0 |
             return template.evaluateAsString(context);
289 |  |
         }
290 |  |
291 |  |
         /**
292 |  |
          * Evaluates the string template against the current context
293 |  |
          * and returns the value.
294 |  |
          * @param templateName The name of the template.
295 |  |
          * @return The output from the evaluated template
296 |  |
          */
297 |  |
         public String eval (String templateName) throws Exception
298 |  |
         {
299 | 0 |
             return eval(context, templateName, null, null);
300 |  |
         }
301 |  |
302 |  |
         /**
303 |  |
          * Evaluate the named template against the given context
304 |  |
          * and return the result as a String.
305 |  |
          * If an output stream is specified, the return value is
306 |  |
          * also written out to the stream.
307 |  |
          *
308 |  |
          * @param templateName The name of the template.
309 |  |
          * @param out An optional output stream.
310 |  |
          * @return The output from the evaluated template
311 |  |
          */
312 |  |
         public String eval (Context context, String templateName, OutputStream out)
313 |  |
                 throws Exception
314 |  |
         {
315 | 0 |
             return eval(context, templateName, out, null);
316 |  |
         }
317 |  |
318 |  |
         /**
319 |  |
          * Evaluates the context using a file template sending the output to a disk file.
320 |  |
          * <p>
321 |  |
          * This method is the preferred method when an output stream is to be written
322 |  |
          * as well as the value of the string is to be returned.
323 |  |
          *
324 |  |
          * @param context The context to use.
325 |  |
          * @param templateName The input template file in the resource path.
326 |  |
          * @param out The output stream. If null, an attempt will be made to locate
327 |  |
          *   the outputstream in the context using the output stream key if
328 |  |
          *   in the context. If no output stream can be resolved, the method does not
329 |  |
          *   throw an exception.
330 |  |
          * @param encoding If null, the platform's encoding will be used.
331 |  |
          * @return The output from the evaluation of the template.
332 |  |
          */
333 |  |
         public String eval (Context context, String templateName, OutputStream out,
334 |  |
                 String encoding) throws Exception
335 |  |
         {
336 | 0 |
             Template t = wm.getTemplate(templateName);
337 | 0 |
             String value = t.evaluateAsString(context);
338 |  |
             // output the file
339 | 0 |
             if (out == null) {
340 | 0 |
                 String outputFileName = (String) context.get(outputContextKey);
341 | 0 |
                 if (outputFileName != null) {
342 | 0 |
                     out = new FileOutputStream(outputFileName);
343 |  |
                 }
344 |  |
             }
345 | 0 |
             if (out != null) // write it to out
346 |  |
             {
347 | 0 |
                 if (encoding == null) {
348 | 0 |
                     out.write(value.getBytes());
349 |  |
                 } else {
350 | 0 |
                     out.write(value.getBytes(encoding));
351 |  |
                 }
352 | 0 |
                 out.close();
353 |  |
             }
354 | 0 |
             this.currentTemplate = t;
355 | 0 |
             this.context = context;
356 | 0 |
             return value;
357 |  |
         }
358 |  |
         /**
359 |  |
          * Evaluates the string template against a new context and writes
360 |  |
          * it to the http Response output stream using the proper encoding.
361 |  |
          * <p>
362 |  |
          * This is an exceptionally useful method for a servlet to use to
363 |  |
          * write out a template.
364 |  |
          * <p>
365 |  |
          * @param context The WM context to use.
366 |  |
          * @param templateName The name of the template.
367 |  |
          * @param resp The servlet response from which the encoding will be derived.
368 |  |
          * @return The output from the evaluated template.
369 |  |
          */
370 |  |
         public String eval (WebContext context, String templateName,
371 |  |
                 HttpServletResponse resp) throws ServletException
372 |  |
         {
373 | 0 |
             String value = null;
374 |  |
             try {
375 | 0 |
                 resp.setContentType("text/html");
376 | 0 |
                 String encoding = wm
377 |  |
                         .getConfig(WMConstants.TEMPLATE_OUTPUT_ENCODING);
378 | 0 |
                 value = eval(context, templateName, resp.getOutputStream(),
379 |  |
                         encoding);
380 | 0 |
             } catch (Exception e) {
381 | 0 |
                 throw new ServletException(e);
382 | 0 |
             }
383 | 0 |
             return value;
384 |  |
         }
385 |  |
386 |  |
387 |  |
         /**
388 |  |
          *  Evaluate the named template against the given context.
389 |  |
          *  Writes the output to the given output file.
390 |  |
          *
391 |  |
          * @param context the context to evaluate the template against
392 |  |
          * @param templateName  the name of the template to evaluate
393 |  |
          * @param outputFileName name of file to output to
394 |  |
          * @param append whether to apppend output
395 |  |
          * @param encoding the encoding to use, may be null
396 |  |
          * @return the String resulting from evaluating the template against the context
397 |  |
          * @throws Exception
398 |  |
          */
399 |  |
         public String eval (Context context, String templateName,
400 |  |
                 String outputFileName, boolean append, String encoding)
401 |  |
             throws Exception
402 |  |
         {
403 | 0 |
             OutputStream out = new FileOutputStream(outputFileName, append);
404 | 0 |
             return eval(context, templateName, out, encoding);
405 |  |
         }
406 |  |
407 |  |
         /**
408 |  |
          * Free up resources when no longer needed.
409 |  |
          */
410 |  |
         public void destroy ()
411 |  |
         {
412 | 0 |
             wm = null;
413 | 0 |
             currentTemplate = null;
414 | 0 |
             context = null;
415 | 0 |
         }
416 |  |
     }