| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| WMEval |
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| 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 | } |