1 /* -*- c-basic-offset: 4; indent-tabs-mode: nil; -*- //------100-columns-wide------>|*/ 2 // for license please see accompanying LICENSE.txt file (available also at http://www.xmlpull.org/) 3 4 package org.xmlpull.v1; 5 6 import java.io.InputStream; 7 import java.io.IOException; 8 import java.io.Reader; 9 10 /** 11 * XML Pull Parser is an interface that defines parsing functionality provided 12 * in <a href="http://www.xmlpull.org/">XMLPULL V1 API</a> (visit this website to 13 * learn more about API and its implementations). 14 * 15 * <p>There are following different 16 * kinds of parser depending on which features are set:<ul> 17 * <li><b>non-validating</b> parser as defined in XML 1.0 spec when 18 * FEATURE_PROCESS_DOCDECL is set to true 19 * <li><b>validating parser</b> as defined in XML 1.0 spec when 20 * FEATURE_VALIDATION is true (and that implies that FEATURE_PROCESS_DOCDECL is true) 21 * <li>when FEATURE_PROCESS_DOCDECL is false (this is default and 22 * if different value is required necessary must be changed before parsing is started) 23 * then parser behaves like XML 1.0 compliant non-validating parser under condition that 24 * <em>no DOCDECL is present</em> in XML documents 25 * (internal entites can still be defined with defineEntityReplacementText()). 26 * This mode of operation is intended <b>for operation in constrained environments</b> such as J2ME. 27 * </ul> 28 * 29 * 30 * <p>There are two key methods: next() and nextToken(). While next() provides 31 * access to high level parsing events, nextToken() allows access to lower 32 * level tokens. 33 * 34 * <p>The current event state of the parser 35 * can be determined by calling the 36 * <a href="#getEventType()">getEventType()</a> method. 37 * Initially, the parser is in the <a href="#START_DOCUMENT">START_DOCUMENT</a> 38 * state. 39 * 40 * <p>The method <a href="#next()">next()</a> advances the parser to the 41 * next event. The int value returned from next determines the current parser 42 * state and is identical to the value returned from following calls to 43 * getEventType (). 44 * 45 * <p>Th following event types are seen by next()<dl> 46 * <dt><a href="#START_TAG">START_TAG</a><dd> An XML start tag was read. 47 * <dt><a href="#TEXT">TEXT</a><dd> Text content was read; 48 * the text content can be retrieved using the getText() method. 49 * (when in validating mode next() will not report ignorable whitespace, use nextToken() instead) 50 * <dt><a href="#END_TAG">END_TAG</a><dd> An end tag was read 51 * <dt><a href="#END_DOCUMENT">END_DOCUMENT</a><dd> No more events are available 52 * </dl> 53 * 54 * <p>after first next() or nextToken() (or any other next*() method) 55 * is called user application can obtain 56 * XML version, standalone and encoding from XML declaration 57 * in following ways:<ul> 58 * <li><b>version</b>: 59 * getProperty("<a href="http://xmlpull.org/v1/doc/properties.html#xmldecl-version">http://xmlpull.org/v1/doc/properties.html#xmldecl-version</a>") 60 * returns String ("1.0") or null if XMLDecl was not read or if property is not supported 61 * <li><b>standalone</b>: 62 * getProperty("<a href="http://xmlpull.org/v1/doc/properties.html#xmldecl-standalone">http://xmlpull.org/v1/doc/properties.html#xmldecl-standalone</a>") 63 * returns Boolean: null if there was no standalone declaration 64 * or if property is not supported 65 * otherwise returns Boolean(true) if standalone="yes" and Boolean(false) when standalone="no" 66 * <li><b>encoding</b>: obtained from getInputEncoding() 67 * null if stream had unknown encoding (not set in setInputStream) 68 * and it was not declared in XMLDecl 69 * </ul> 70 * 71 * A minimal example for using this API may look as follows: 72 * <pre> 73 * import java.io.IOException; 74 * import java.io.StringReader; 75 * 76 * import org.xmlpull.v1.XmlPullParser; 77 * import org.xmlpull.v1.<a href="XmlPullParserException.html">XmlPullParserException</a>; 78 * import org.xmlpull.v1.<a href="XmlPullParserFactory.html">XmlPullParserFactory</a>; 79 * 80 * public class SimpleXmlPullApp 81 * { 82 * 83 * public static void main (String args[]) 84 * throws XmlPullParserException, IOException 85 * { 86 * XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 87 * factory.setNamespaceAware(true); 88 * XmlPullParser xpp = factory.newPullParser(); 89 * 90 * xpp.<a href="#setInput">setInput</a>( new StringReader ( "<foo>Hello World!</foo>" ) ); 91 * int eventType = xpp.getEventType(); 92 * while (eventType != XmlPullParser.END_DOCUMENT) { 93 * if(eventType == XmlPullParser.START_DOCUMENT) { 94 * System.out.println("Start document"); 95 * } else if(eventType == XmlPullParser.START_TAG) { 96 * System.out.println("Start tag "+xpp.<a href="#getName()">getName()</a>); 97 * } else if(eventType == XmlPullParser.END_TAG) { 98 * System.out.println("End tag "+xpp.getName()); 99 * } else if(eventType == XmlPullParser.TEXT) { 100 * System.out.println("Text "+xpp.<a href="#getText()">getText()</a>); 101 * } 102 * eventType = xpp.next(); 103 * } 104 * System.out.println("End document"); 105 * } 106 * } 107 * </pre> 108 * 109 * <p>The above example will generate the following output: 110 * <pre> 111 * Start document 112 * Start tag foo 113 * Text Hello World! 114 * End tag foo 115 * End document 116 * </pre> 117 * 118 * <p>For more details on API usage, please refer to the 119 * quick Introduction available at <a href="http://www.xmlpull.org">http://www.xmlpull.org</a> 120 * 121 * @see XmlPullParserFactory 122 * @see #defineEntityReplacementText 123 * @see #getName 124 * @see #getNamespace 125 * @see #getText 126 * @see #next 127 * @see #nextToken 128 * @see #setInput 129 * @see #FEATURE_PROCESS_DOCDECL 130 * @see #FEATURE_VALIDATION 131 * @see #START_DOCUMENT 132 * @see #START_TAG 133 * @see #TEXT 134 * @see #END_TAG 135 * @see #END_DOCUMENT 136 * 137 * @author <a href="http://www-ai.cs.uni-dortmund.de/PERSONAL/haustein.html">Stefan Haustein</a> 138 * @author <a href="http://www.extreme.indiana.edu/~aslom/">Aleksander Slominski</a> 139 */ 140 141 public interface XmlPullParser { 142 143 /** This constant represents the default namespace (empty string "") */ 144 String NO_NAMESPACE = ""; 145 146 // ---------------------------------------------------------------------------- 147 // EVENT TYPES as reported by next() 148 149 /** 150 * Signalize that parser is at the very beginning of the document 151 * and nothing was read yet. 152 * This event type can only be observed by calling getEvent() 153 * before the first call to next(), nextToken, or nextTag()</a>). 154 * 155 * @see #next 156 * @see #nextToken 157 */ 158 int START_DOCUMENT = 0; 159 160 /** 161 * Logical end of the xml document. Returned from getEventType, next() 162 * and nextToken() 163 * when the end of the input document has been reached. 164 * <p><strong>NOTE:</strong> subsequent calls to 165 * <a href="#next()">next()</a> or <a href="#nextToken()">nextToken()</a> 166 * may result in exception being thrown. 167 * 168 * @see #next 169 * @see #nextToken 170 */ 171 int END_DOCUMENT = 1; 172 173 /** 174 * Returned from getEventType(), 175 * <a href="#next()">next()</a>, <a href="#nextToken()">nextToken()</a> when 176 * a start tag was read. 177 * The name of start tag is available from getName(), its namespace and prefix are 178 * available from getNamespace() and getPrefix() 179 * if <a href='#FEATURE_PROCESS_NAMESPACES'>namespaces are enabled</a>. 180 * See getAttribute* methods to retrieve element attributes. 181 * See getNamespace* methods to retrieve newly declared namespaces. 182 * 183 * @see #next 184 * @see #nextToken 185 * @see #getName 186 * @see #getPrefix 187 * @see #getNamespace 188 * @see #getAttributeCount 189 * @see #getDepth 190 * @see #getNamespaceCount 191 * @see #getNamespace 192 * @see #FEATURE_PROCESS_NAMESPACES 193 */ 194 int START_TAG = 2; 195 196 /** 197 * Returned from getEventType(), <a href="#next()">next()</a>, or 198 * <a href="#nextToken()">nextToken()</a> when an end tag was read. 199 * The name of start tag is available from getName(), its 200 * namespace and prefix are 201 * available from getNamespace() and getPrefix(). 202 * 203 * @see #next 204 * @see #nextToken 205 * @see #getName 206 * @see #getPrefix 207 * @see #getNamespace 208 * @see #FEATURE_PROCESS_NAMESPACES 209 */ 210 int END_TAG = 3; 211 212 213 /** 214 * Character data was read and will is available by calling getText(). 215 * <p><strong>Please note:</strong> <a href="#next()">next()</a> will 216 * accumulate multiple 217 * events into one TEXT event, skipping IGNORABLE_WHITESPACE, 218 * PROCESSING_INSTRUCTION and COMMENT events, 219 * In contrast, <a href="#nextToken()">nextToken()</a> will stop reading 220 * text when any other event is observed. 221 * Also, when the state was reached by calling next(), the text value will 222 * be normalized, whereas getText() will 223 * return unnormalized content in the case of nextToken(). This allows 224 * an exact roundtrip without changing line ends when examining low 225 * level events, whereas for high level applications the text is 226 * normalized appropriately. 227 * 228 * @see #next 229 * @see #nextToken 230 * @see #getText 231 */ 232 int TEXT = 4; 233 234 // ---------------------------------------------------------------------------- 235 // additional events exposed by lower level nextToken() 236 237 /** 238 * A CDATA sections was just read; 239 * this token is available only from calls to <a href="#nextToken()">nextToken()</a>. 240 * A call to next() will accumulate various text events into a single event 241 * of type TEXT. The text contained in the CDATA section is available 242 * by calling getText(). 243 * 244 * @see #nextToken 245 * @see #getText 246 */ 247 int CDSECT = 5; 248 249 /** 250 * An entity reference was just read; 251 * this token is available from <a href="#nextToken()">nextToken()</a> 252 * only. The entity name is available by calling getName(). If available, 253 * the replacement text can be obtained by calling getText(); otherwise, 254 * the user is responsible for resolving the entity reference. 255 * This event type is never returned from next(); next() will 256 * accumulate the replacement text and other text 257 * events to a single TEXT event. 258 * 259 * @see #nextToken 260 * @see #getText 261 */ 262 int ENTITY_REF = 6; 263 264 /** 265 * Ignorable whitespace was just read. 266 * This token is available only from <a href="#nextToken()">nextToken()</a>). 267 * For non-validating 268 * parsers, this event is only reported by nextToken() when outside 269 * the root element. 270 * Validating parsers may be able to detect ignorable whitespace at 271 * other locations. 272 * The ignorable whitespace string is available by calling getText() 273 * 274 * <p><strong>NOTE:</strong> this is different from calling the 275 * isWhitespace() method, since text content 276 * may be whitespace but not ignorable. 277 * 278 * Ignorable whitespace is skipped by next() automatically; this event 279 * type is never returned from next(). 280 * 281 * @see #nextToken 282 * @see #getText 283 */ 284 int IGNORABLE_WHITESPACE = 7; 285 286 /** 287 * An XML processing instruction declaration was just read. This 288 * event type is available only via <a href="#nextToken()">nextToken()</a>. 289 * getText() will return text that is inside the processing instruction. 290 * Calls to next() will skip processing instructions automatically. 291 * @see #nextToken 292 * @see #getText 293 */ 294 int PROCESSING_INSTRUCTION = 8; 295 296 /** 297 * An XML comment was just read. This event type is this token is 298 * available via <a href="#nextToken()">nextToken()</a> only; 299 * calls to next() will skip comments automatically. 300 * The content of the comment can be accessed using the getText() 301 * method. 302 * 303 * @see #nextToken 304 * @see #getText 305 */ 306 int COMMENT = 9; 307 308 /** 309 * An XML document type declaration was just read. This token is 310 * available from <a href="#nextToken()">nextToken()</a> only. 311 * The unparsed text inside the doctype is available via 312 * the getText() method. 313 * 314 * @see #nextToken 315 * @see #getText 316 */ 317 int DOCDECL = 10; 318 319 /** 320 * This array can be used to convert the event type integer constants 321 * such as START_TAG or TEXT to 322 * to a string. For example, the value of TYPES[START_TAG] is 323 * the string "START_TAG". 324 * 325 * This array is intended for diagnostic output only. Relying 326 * on the contents of the array may be dangerous since malicious 327 * applications may alter the array, although it is final, due 328 * to limitations of the Java language. 329 */ 330 String [] TYPES = { 331 "START_DOCUMENT", 332 "END_DOCUMENT", 333 "START_TAG", 334 "END_TAG", 335 "TEXT", 336 "CDSECT", 337 "ENTITY_REF", 338 "IGNORABLE_WHITESPACE", 339 "PROCESSING_INSTRUCTION", 340 "COMMENT", 341 "DOCDECL" 342 }; 343 344 345 // ---------------------------------------------------------------------------- 346 // namespace related features 347 348 /** 349 * This feature determines whether the parser processes 350 * namespaces. As for all features, the default value is false. 351 * <p><strong>NOTE:</strong> The value can not be changed during 352 * parsing an must be set before parsing. 353 * 354 * @see #getFeature 355 * @see #setFeature 356 */ 357 String FEATURE_PROCESS_NAMESPACES = 358 "http://xmlpull.org/v1/doc/features.html#process-namespaces"; 359 360 /** 361 * This feature determines whether namespace attributes are 362 * exposed via the attribute access methods. Like all features, 363 * the default value is false. This feature cannot be changed 364 * during parsing. 365 * 366 * @see #getFeature 367 * @see #setFeature 368 */ 369 String FEATURE_REPORT_NAMESPACE_ATTRIBUTES = 370 "http://xmlpull.org/v1/doc/features.html#report-namespace-prefixes"; 371 372 /** 373 * This feature determines whether the document declaration 374 * is processed. If set to false, 375 * the DOCDECL event type is reported by nextToken() 376 * and ignored by next(). 377 * 378 * If this feature is activated, then the document declaration 379 * must be processed by the parser. 380 * 381 * <p><strong>Please note:</strong> If the document type declaration 382 * was ignored, entity references may cause exceptions 383 * later in the parsing process. 384 * The default value of this feature is false. It cannot be changed 385 * during parsing. 386 * 387 * @see #getFeature 388 * @see #setFeature 389 */ 390 String FEATURE_PROCESS_DOCDECL = 391 "http://xmlpull.org/v1/doc/features.html#process-docdecl"; 392 393 /** 394 * If this feature is activated, all validation errors as 395 * defined in the XML 1.0 specification are reported. 396 * This implies that FEATURE_PROCESS_DOCDECL is true and both, the 397 * internal and external document type declaration will be processed. 398 * <p><strong>Please Note:</strong> This feature can not be changed 399 * during parsing. The default value is false. 400 * 401 * @see #getFeature 402 * @see #setFeature 403 */ 404 String FEATURE_VALIDATION = 405 "http://xmlpull.org/v1/doc/features.html#validation"; 406 407 /** 408 * Use this call to change the general behaviour of the parser, 409 * such as namespace processing or doctype declaration handling. 410 * This method must be called before the first call to next or 411 * nextToken. Otherwise, an exception is thrown. 412 * <p>Example: call setFeature(FEATURE_PROCESS_NAMESPACES, true) in order 413 * to switch on namespace processing. The initial settings correspond 414 * to the properties requested from the XML Pull Parser factory. 415 * If none were requested, all features are deactivated by default. 416 * 417 * @exception XmlPullParserException If the feature is not supported or can not be set 418 * @exception IllegalArgumentException If string with the feature name is null 419 */ 420 void setFeature(String name, 421 boolean state) throws XmlPullParserException; 422 423 /** 424 * Returns the current value of the given feature. 425 * <p><strong>Please note:</strong> unknown features are 426 * <strong>always</strong> returned as false. 427 * 428 * @param name The name of feature to be retrieved. 429 * @return The value of the feature. 430 * @exception IllegalArgumentException if string the feature name is null 431 */ 432 433 boolean getFeature(String name); 434 435 /** 436 * Set the value of a property. 437 * 438 * The property name is any fully-qualified URI. 439 * 440 * @exception XmlPullParserException If the property is not supported or can not be set 441 * @exception IllegalArgumentException If string with the property name is null 442 */ 443 void setProperty(String name, 444 Object value) throws XmlPullParserException; 445 446 /** 447 * Look up the value of a property. 448 * 449 * The property name is any fully-qualified URI. 450 * <p><strong>NOTE:</strong> unknown properties are <strong>always</strong> 451 * returned as null. 452 * 453 * @param name The name of property to be retrieved. 454 * @return The value of named property. 455 */ 456 Object getProperty(String name); 457 458 459 /** 460 * Set the input source for parser to the given reader and 461 * resets the parser. The event type is set to the initial value 462 * START_DOCUMENT. 463 * Setting the reader to null will just stop parsing and 464 * reset parser state, 465 * allowing the parser to free internal resources 466 * such as parsing buffers. 467 */ 468 void setInput(Reader in) throws XmlPullParserException; 469 470 471 /** 472 * Sets the input stream the parser is going to process. 473 * This call resets the parser state and sets the event type 474 * to the initial value START_DOCUMENT. 475 * 476 * <p><strong>NOTE:</strong> If an input encoding string is passed, 477 * it MUST be used. Otherwise, 478 * if inputEncoding is null, the parser SHOULD try to determine 479 * input encoding following XML 1.0 specification (see below). 480 * If encoding detection is supported then following feature 481 * <a href="http://xmlpull.org/v1/doc/features.html#detect-encoding">http://xmlpull.org/v1/doc/features.html#detect-encoding</a> 482 * MUST be true amd otherwise it must be false 483 * 484 * @param inputStream contains a raw byte input stream of possibly 485 * unknown encoding (when inputEncoding is null). 486 * 487 * @param inputEncoding if not null it MUST be used as encoding for inputStream 488 */ 489 void setInput(InputStream inputStream, String inputEncoding) 490 throws XmlPullParserException; 491 492 /** 493 * Returns the input encoding if known, null otherwise. 494 * If setInput(InputStream, inputEncoding) was called with an inputEncoding 495 * value other than null, this value must be returned 496 * from this method. Otherwise, if inputEncoding is null and 497 * the parser supports the encoding detection feature 498 * (http://xmlpull.org/v1/doc/features.html#detect-encoding), 499 * it must return the detected encoding. 500 * If setInput(Reader) was called, null is returned. 501 * After first call to next if XML declaration was present this method 502 * will return encoding declared. 503 */ 504 String getInputEncoding(); 505 506 /** 507 * Set new value for entity replacement text as defined in 508 * <a href="http://www.w3.org/TR/REC-xml#intern-replacement">XML 1.0 Section 4.5 509 * Construction of Internal Entity Replacement Text</a>. 510 * If FEATURE_PROCESS_DOCDECL or FEATURE_VALIDATION are set, calling this 511 * function will result in an exception -- when processing of DOCDECL is 512 * enabled, there is no need to the entity replacement text manually. 513 * 514 * <p>The motivation for this function is to allow very small 515 * implementations of XMLPULL that will work in J2ME environments. 516 * Though these implementations may not be able to process the document type 517 * declaration, they still can work with known DTDs by using this function. 518 * 519 * <p><b>Please notes:</b> The given value is used literally as replacement text 520 * and it corresponds to declaring entity in DTD that has all special characters 521 * escaped: left angle bracket is replaced with &lt;, ampersand with &amp; 522 * and so on. 523 * 524 * <p><b>Note:</b> The given value is the literal replacement text and must not 525 * contain any other entity reference (if it contains any entity reference 526 * there will be no further replacement). 527 * 528 * <p><b>Note:</b> The list of pre-defined entity names will 529 * always contain standard XML entities such as 530 * amp (&amp;), lt (&lt;), gt (&gt;), quot (&quot;), and apos (&apos;). 531 * Those cannot be redefined by this method! 532 * 533 * @see #setInput 534 * @see #FEATURE_PROCESS_DOCDECL 535 * @see #FEATURE_VALIDATION 536 */ 537 void defineEntityReplacementText( String entityName, 538 String replacementText ) throws XmlPullParserException; 539 540 /** 541 * Returns the numbers of elements in the namespace stack for the given 542 * depth. 543 * If namespaces are not enabled, 0 is returned. 544 * 545 * <p><b>NOTE:</b> when parser is on END_TAG then it is allowed to call 546 * this function with getDepth()+1 argument to retrieve position of namespace 547 * prefixes and URIs that were declared on corresponding START_TAG. 548 * <p><b>NOTE:</b> to retrieve list of namespaces declared in current element:<pre> 549 * XmlPullParser pp = ... 550 * int nsStart = pp.getNamespaceCount(pp.getDepth()-1); 551 * int nsEnd = pp.getNamespaceCount(pp.getDepth()); 552 * for (int i = nsStart; i < nsEnd; i++) { 553 * String prefix = pp.getNamespacePrefix(i); 554 * String ns = pp.getNamespaceUri(i); 555 * // ... 556 * } 557 * </pre> 558 * 559 * @see #getNamespacePrefix 560 * @see #getNamespaceUri 561 * @see #getNamespace() 562 * @see #getNamespace(String) 563 */ 564 int getNamespaceCount(int depth) throws XmlPullParserException; 565 566 /** 567 * Returns the namespace prefix for the given position 568 * in the namespace stack. 569 * Default namespace declaration (xmlns='...') will have null as prefix. 570 * If the given index is out of range, an exception is thrown. 571 * <p><b>Please note:</b> when the parser is on an END_TAG, 572 * namespace prefixes that were declared 573 * in the corresponding START_TAG are still accessible 574 * although they are no longer in scope. 575 */ 576 String getNamespacePrefix(int pos) throws XmlPullParserException; 577 578 /** 579 * Returns the namespace URI for the given position in the 580 * namespace stack 581 * If the position is out of range, an exception is thrown. 582 * <p><b>NOTE:</b> when parser is on END_TAG then namespace prefixes that were declared 583 * in corresponding START_TAG are still accessible even though they are not in scope 584 */ 585 String getNamespaceUri(int pos) throws XmlPullParserException; 586 587 /** 588 * Returns the URI corresponding to the given prefix, 589 * depending on current state of the parser. 590 * 591 * <p>If the prefix was not declared in the current scope, 592 * null is returned. The default namespace is included 593 * in the namespace table and is available via 594 * getNamespace (null). 595 * 596 * <p>This method is a convenience method for 597 * 598 * <pre> 599 * for (int i = getNamespaceCount(getDepth ())-1; i >= 0; i--) { 600 * if (getNamespacePrefix(i).equals( prefix )) { 601 * return getNamespaceUri(i); 602 * } 603 * } 604 * return null; 605 * </pre> 606 * 607 * <p><strong>Please note:</strong> parser implementations 608 * may provide more efficient lookup, e.g. using a Hashtable. 609 * The 'xml' prefix is bound to "http://www.w3.org/XML/1998/namespace", as 610 * defined in the 611 * <a href="http://www.w3.org/TR/REC-xml-names/#ns-using">Namespaces in XML</a> 612 * specification. Analogous, the 'xmlns' prefix is resolved to 613 * <a href="http://www.w3.org/2000/xmlns/">http://www.w3.org/2000/xmlns/</a> 614 * 615 * @see #getNamespaceCount 616 * @see #getNamespacePrefix 617 * @see #getNamespaceUri 618 */ 619 String getNamespace (String prefix); 620 621 622 // -------------------------------------------------------------------------- 623 // miscellaneous reporting methods 624 625 /** 626 * Returns the current depth of the element. 627 * Outside the root element, the depth is 0. The 628 * depth is incremented by 1 when a start tag is reached. 629 * The depth is decremented AFTER the end tag 630 * event was observed. 631 * 632 * <pre> 633 * <!-- outside --> 0 634 * <root> 1 635 * sometext 1 636 * <foobar> 2 637 * </foobar> 2 638 * </root> 1 639 * <!-- outside --> 0 640 * </pre> 641 */ 642 int getDepth(); 643 644 /** 645 * Returns a short text describing the current parser state, including 646 * the position, a 647 * description of the current event and the data source if known. 648 * This method is especially useful to provide meaningful 649 * error messages and for debugging purposes. 650 */ 651 String getPositionDescription (); 652 653 654 /** 655 * Returns the current line number, starting from 1. 656 * When the parser does not know the current line number 657 * or can not determine it, -1 is returned (e.g. for WBXML). 658 * 659 * @return current line number or -1 if unknown. 660 */ 661 int getLineNumber(); 662 663 /** 664 * Returns the current column number, starting from 0. 665 * When the parser does not know the current column number 666 * or can not determine it, -1 is returned (e.g. for WBXML). 667 * 668 * @return current column number or -1 if unknown. 669 */ 670 int getColumnNumber(); 671 672 673 // -------------------------------------------------------------------------- 674 // TEXT related methods 675 676 /** 677 * Checks whether the current TEXT event contains only whitespace 678 * characters. 679 * For IGNORABLE_WHITESPACE, this is always true. 680 * For TEXT and CDSECT, false is returned when the current event text 681 * contains at least one non-white space character. For any other 682 * event type an exception is thrown. 683 * 684 * <p><b>Please note:</b> non-validating parsers are not 685 * able to distinguish whitespace and ignorable whitespace, 686 * except from whitespace outside the root element. Ignorable 687 * whitespace is reported as separate event, which is exposed 688 * via nextToken only. 689 * 690 */ 691 boolean isWhitespace() throws XmlPullParserException; 692 693 /** 694 * Returns the text content of the current event as String. 695 * The value returned depends on current event type, 696 * for example for TEXT event it is element content 697 * (this is typical case when next() is used). 698 * 699 * See description of nextToken() for detailed description of 700 * possible returned values for different types of events. 701 * 702 * <p><strong>NOTE:</strong> in case of ENTITY_REF, this method returns 703 * the entity replacement text (or null if not available). This is 704 * the only case where 705 * getText() and getTextCharacters() return different values. 706 * 707 * @see #getEventType 708 * @see #next 709 * @see #nextToken 710 */ 711 String getText (); 712 713 714 /** 715 * Returns the buffer that contains the text of the current event, 716 * as well as the start offset and length relevant for the current 717 * event. See getText(), next() and nextToken() for description of possible returned values. 718 * 719 * <p><strong>Please note:</strong> this buffer must not 720 * be modified and its content MAY change after a call to 721 * next() or nextToken(). This method will always return the 722 * same value as getText(), except for ENTITY_REF. In the case 723 * of ENTITY ref, getText() returns the replacement text and 724 * this method returns the actual input buffer containing the 725 * entity name. 726 * If getText() returns null, this method returns null as well and 727 * the values returned in the holder array MUST be -1 (both start 728 * and length). 729 * 730 * @see #getText 731 * @see #next 732 * @see #nextToken 733 * 734 * @param holderForStartAndLength Must hold an 2-element int array 735 * into which the start offset and length values will be written. 736 * @return char buffer that contains the text of the current event 737 * (null if the current event has no text associated). 738 */ 739 char[] getTextCharacters(int [] holderForStartAndLength); 740 741 // -------------------------------------------------------------------------- 742 // START_TAG / END_TAG shared methods 743 744 /** 745 * Returns the namespace URI of the current element. 746 * The default namespace is represented 747 * as empty string. 748 * If namespaces are not enabled, an empty String ("") is always returned. 749 * The current event must be START_TAG or END_TAG; otherwise, 750 * null is returned. 751 */ 752 String getNamespace (); 753 754 /** 755 * For START_TAG or END_TAG events, the (local) name of the current 756 * element is returned when namespaces are enabled. When namespace 757 * processing is disabled, the raw name is returned. 758 * For ENTITY_REF events, the entity name is returned. 759 * If the current event is not START_TAG, END_TAG, or ENTITY_REF, 760 * null is returned. 761 * <p><b>Please note:</b> To reconstruct the raw element name 762 * when namespaces are enabled and the prefix is not null, 763 * you will need to add the prefix and a colon to localName.. 764 * 765 */ 766 String getName(); 767 768 /** 769 * Returns the prefix of the current element. 770 * If the element is in the default namespace (has no prefix), 771 * null is returned. 772 * If namespaces are not enabled, or the current event 773 * is not START_TAG or END_TAG, null is returned. 774 */ 775 String getPrefix(); 776 777 /** 778 * Returns true if the current event is START_TAG and the tag 779 * is degenerated 780 * (e.g. <foobar/>). 781 * <p><b>NOTE:</b> if the parser is not on START_TAG, an exception 782 * will be thrown. 783 */ 784 boolean isEmptyElementTag() throws XmlPullParserException; 785 786 // -------------------------------------------------------------------------- 787 // START_TAG Attributes retrieval methods 788 789 /** 790 * Returns the number of attributes of the current start tag, or 791 * -1 if the current event type is not START_TAG 792 * 793 * @see #getAttributeNamespace 794 * @see #getAttributeName 795 * @see #getAttributePrefix 796 * @see #getAttributeValue 797 */ 798 int getAttributeCount(); 799 800 /** 801 * Returns the namespace URI of the attribute 802 * with the given index (starts from 0). 803 * Returns an empty string ("") if namespaces are not enabled 804 * or the attribute has no namespace. 805 * Throws an IndexOutOfBoundsException if the index is out of range 806 * or the current event type is not START_TAG. 807 * 808 * <p><strong>NOTE:</strong> if FEATURE_REPORT_NAMESPACE_ATTRIBUTES is set 809 * then namespace attributes (xmlns:ns='...') must be reported 810 * with namespace 811 * <a href="http://www.w3.org/2000/xmlns/">http://www.w3.org/2000/xmlns/</a> 812 * (visit this URL for description!). 813 * The default namespace attribute (xmlns="...") will be reported with empty namespace. 814 * <p><strong>NOTE:</strong>The xml prefix is bound as defined in 815 * <a href="http://www.w3.org/TR/REC-xml-names/#ns-using">Namespaces in XML</a> 816 * specification to "http://www.w3.org/XML/1998/namespace". 817 * 818 * @param index zero-based index of attribute 819 * @return attribute namespace, 820 * empty string ("") is returned if namespaces processing is not enabled or 821 * namespaces processing is enabled but attribute has no namespace (it has no prefix). 822 */ 823 String getAttributeNamespace (int index); 824 825 /** 826 * Returns the local name of the specified attribute 827 * if namespaces are enabled or just attribute name if namespaces are disabled. 828 * Throws an IndexOutOfBoundsException if the index is out of range 829 * or current event type is not START_TAG. 830 * 831 * @param index zero-based index of attribute 832 * @return attribute name (null is never returned) 833 */ 834 String getAttributeName (int index); 835 836 /** 837 * Returns the prefix of the specified attribute 838 * Returns null if the element has no prefix. 839 * If namespaces are disabled it will always return null. 840 * Throws an IndexOutOfBoundsException if the index is out of range 841 * or current event type is not START_TAG. 842 * 843 * @param index zero-based index of attribute 844 * @return attribute prefix or null if namespaces processing is not enabled. 845 */ 846 String getAttributePrefix(int index); 847 848 /** 849 * Returns the type of the specified attribute 850 * If parser is non-validating it MUST return CDATA. 851 * 852 * @param index zero-based index of attribute 853 * @return attribute type (null is never returned) 854 */ 855 String getAttributeType(int index); 856 857 /** 858 * Returns if the specified attribute was not in input was declared in XML. 859 * If parser is non-validating it MUST always return false. 860 * This information is part of XML infoset: 861 * 862 * @param index zero-based index of attribute 863 * @return false if attribute was in input 864 */ 865 boolean isAttributeDefault(int index); 866 867 /** 868 * Returns the given attributes value. 869 * Throws an IndexOutOfBoundsException if the index is out of range 870 * or current event type is not START_TAG. 871 * 872 * <p><strong>NOTE:</strong> attribute value must be normalized 873 * (including entity replacement text if PROCESS_DOCDECL is false) as described in 874 * <a href="http://www.w3.org/TR/REC-xml#AVNormalize">XML 1.0 section 875 * 3.3.3 Attribute-Value Normalization</a> 876 * 877 * @see #defineEntityReplacementText 878 * 879 * @param index zero-based index of attribute 880 * @return value of attribute (null is never returned) 881 */ 882 String getAttributeValue(int index); 883 884 /** 885 * Returns the attributes value identified by namespace URI and namespace localName. 886 * If namespaces are disabled namespace must be null. 887 * If current event type is not START_TAG then IndexOutOfBoundsException will be thrown. 888 * 889 * <p><strong>NOTE:</strong> attribute value must be normalized 890 * (including entity replacement text if PROCESS_DOCDECL is false) as described in 891 * <a href="http://www.w3.org/TR/REC-xml#AVNormalize">XML 1.0 section 892 * 3.3.3 Attribute-Value Normalization</a> 893 * 894 * @see #defineEntityReplacementText 895 * 896 * @param namespace Namespace of the attribute if namespaces are enabled otherwise must be null 897 * @param name If namespaces enabled local name of attribute otherwise just attribute name 898 * @return value of attribute or null if attribute with given name does not exist 899 */ 900 String getAttributeValue(String namespace, 901 String name); 902 903 // -------------------------------------------------------------------------- 904 // actual parsing methods 905 906 /** 907 * Returns the type of the current event (START_TAG, END_TAG, TEXT, etc.) 908 * 909 * @see #next() 910 * @see #nextToken() 911 */ 912 int getEventType() 913 throws XmlPullParserException; 914 915 /** 916 * Get next parsing event - element content will be coalesced and only one 917 * TEXT event must be returned for whole element content 918 * (comments and processing instructions will be ignored and entity references 919 * must be expanded or exception must be thrown if entity reference can not be expanded). 920 * If element content is empty (content is "") then no TEXT event will be reported. 921 * 922 * <p><b>NOTE:</b> empty element (such as <tag/>) will be reported 923 * with two separate events: START_TAG, END_TAG - it must be so to preserve 924 * parsing equivalency of empty element to <tag></tag>. 925 * (see isEmptyElementTag ()) 926 * 927 * @see #isEmptyElementTag 928 * @see #START_TAG 929 * @see #TEXT 930 * @see #END_TAG 931 * @see #END_DOCUMENT 932 */ 933 934 int next() 935 throws XmlPullParserException, IOException; 936 937 938 /** 939 * This method works similarly to next() but will expose 940 * additional event types (COMMENT, CDSECT, DOCDECL, ENTITY_REF, PROCESSING_INSTRUCTION, or 941 * IGNORABLE_WHITESPACE) if they are available in input. 942 * 943 * <p>If special feature 944 * <a href="http://xmlpull.org/v1/doc/features.html#xml-roundtrip">FEATURE_XML_ROUNDTRIP</a> 945 * (identified by URI: http://xmlpull.org/v1/doc/features.html#xml-roundtrip) 946 * is enabled it is possible to do XML document round trip ie. reproduce 947 * exectly on output the XML input using getText(): 948 * returned content is always unnormalized (exactly as in input). 949 * Otherwise returned content is end-of-line normalized as described 950 * <a href="http://www.w3.org/TR/REC-xml#sec-line-ends">XML 1.0 End-of-Line Handling</a> 951 * and. Also when this feature is enabled exact content of START_TAG, END_TAG, 952 * DOCDECL and PROCESSING_INSTRUCTION is available. 953 * 954 * <p>Here is the list of tokens that can be returned from nextToken() 955 * and what getText() and getTextCharacters() returns:<dl> 956 * <dt>START_DOCUMENT<dd>null 957 * <dt>END_DOCUMENT<dd>null 958 * <dt>START_TAG<dd>null unless FEATURE_XML_ROUNDTRIP 959 * enabled and then returns XML tag, ex: <tag attr='val'> 960 * <dt>END_TAG<dd>null unless FEATURE_XML_ROUNDTRIP 961 * id enabled and then returns XML tag, ex: </tag> 962 * <dt>TEXT<dd>return element content. 963 * <br>Note: that element content may be delivered in multiple consecutive TEXT events. 964 * <dt>IGNORABLE_WHITESPACE<dd>return characters that are determined to be ignorable white 965 * space. If the FEATURE_XML_ROUNDTRIP is enabled all whitespace content outside root 966 * element will always reported as IGNORABLE_WHITESPACE otherwise reporting is optional. 967 * <br>Note: that element content may be delivered in multiple consecutive IGNORABLE_WHITESPACE events. 968 * <dt>CDSECT<dd> 969 * return text <em>inside</em> CDATA 970 * (ex. 'fo<o' from <!CDATA[fo<o]]>) 971 * <dt>PROCESSING_INSTRUCTION<dd> 972 * if FEATURE_XML_ROUNDTRIP is true 973 * return exact PI content ex: 'pi foo' from <?pi foo?> 974 * otherwise it may be exact PI content or concatenation of PI target, 975 * space and data so for example for 976 * <?target data?> string "target data" may 977 * be returned if FEATURE_XML_ROUNDTRIP is false. 978 * <dt>COMMENT<dd>return comment content ex. 'foo bar' from <!--foo bar--> 979 * <dt>ENTITY_REF<dd>getText() MUST return entity replacement text if PROCESS_DOCDECL is false 980 * otherwise getText() MAY return null, 981 * additionally getTextCharacters() MUST return entity name 982 * (for example 'entity_name' for &entity_name;). 983 * <br><b>NOTE:</b> this is the only place where value returned from getText() and 984 * getTextCharacters() <b>are different</b> 985 * <br><b>NOTE:</b> it is user responsibility to resolve entity reference 986 * if PROCESS_DOCDECL is false and there is no entity replacement text set in 987 * defineEntityReplacementText() method (getText() will be null) 988 * <br><b>NOTE:</b> character entities (ex. &#32;) and standard entities such as 989 * &amp; &lt; &gt; &quot; &apos; are reported as well 990 * and are <b>not</b> reported as TEXT tokens but as ENTITY_REF tokens! 991 * This requirement is added to allow to do roundtrip of XML documents! 992 * <dt>DOCDECL<dd> 993 * if FEATURE_XML_ROUNDTRIP is true or PROCESS_DOCDECL is false 994 * then return what is inside of DOCDECL for example it returns:<pre> 995 * " titlepage SYSTEM "http://www.foo.bar/dtds/typo.dtd" 996 * [<!ENTITY % active.links "INCLUDE">]"</pre> 997 * <p>for input document that contained:<pre> 998 * <!DOCTYPE titlepage SYSTEM "http://www.foo.bar/dtds/typo.dtd" 999 * [<!ENTITY % active.links "INCLUDE">]></pre> 1000 * otherwise if FEATURE_XML_ROUNDTRIP is false and PROCESS_DOCDECL is true 1001 * then what is returned is undefined (it may be even null) 1002 * </dd> 1003 * </dl> 1004 * 1005 * <p><strong>NOTE:</strong> there is no guarantee that there will only one TEXT or 1006 * IGNORABLE_WHITESPACE event from nextToken() as parser may chose to deliver element content in 1007 * multiple tokens (dividing element content into chunks) 1008 * 1009 * <p><strong>NOTE:</strong> whether returned text of token is end-of-line normalized 1010 * is depending on FEATURE_XML_ROUNDTRIP. 1011 * 1012 * <p><strong>NOTE:</strong> XMLDecl (<?xml ...?>) is not reported but its content 1013 * is available through optional properties (see class description above). 1014 * 1015 * @see #next 1016 * @see #START_TAG 1017 * @see #TEXT 1018 * @see #END_TAG 1019 * @see #END_DOCUMENT 1020 * @see #COMMENT 1021 * @see #DOCDECL 1022 * @see #PROCESSING_INSTRUCTION 1023 * @see #ENTITY_REF 1024 * @see #IGNORABLE_WHITESPACE 1025 */ 1026 int nextToken() 1027 throws XmlPullParserException, IOException; 1028 1029 //----------------------------------------------------------------------------- 1030 // utility methods to mak XML parsing easier ... 1031 1032 /** 1033 * Test if the current event is of the given type and if the 1034 * namespace and name do match. null will match any namespace 1035 * and any name. If the test is not passed, an exception is 1036 * thrown. The exception text indicates the parser position, 1037 * the expected event and the current event that is not meeting the 1038 * requirement. 1039 * 1040 * <p>Essentially it does this 1041 * <pre> 1042 * if (type != getEventType() 1043 * || (namespace != null && !namespace.equals( getNamespace () ) ) 1044 * || (name != null && !name.equals( getName() ) ) ) 1045 * throw new XmlPullParserException( "expected "+ TYPES[ type ]+getPositionDescription()); 1046 * </pre> 1047 */ 1048 void require(int type, String namespace, String name) 1049 throws XmlPullParserException, IOException; 1050 1051 /** 1052 * If current event is START_TAG then if next element is TEXT then element content is returned 1053 * or if next event is END_TAG then empty string is returned, otherwise exception is thrown. 1054 * After calling this function successfully parser will be positioned on END_TAG. 1055 * 1056 * <p>The motivation for this function is to allow to parse consistently both 1057 * empty elements and elements that has non empty content, for example for input: <ol> 1058 * <li><tag>foo</tag> 1059 * <li><tag></tag> (which is equivalent to <tag/> 1060 * both input can be parsed with the same code: 1061 * <pre> 1062 * p.nextTag() 1063 * p.requireEvent(p.START_TAG, "", "tag"); 1064 * String content = p.nextText(); 1065 * p.requireEvent(p.END_TAG, "", "tag"); 1066 * </pre> 1067 * This function together with nextTag make it very easy to parse XML that has 1068 * no mixed content. 1069 * 1070 * 1071 * <p>Essentially it does this 1072 * <pre> 1073 * if(getEventType() != START_TAG) { 1074 * throw new XmlPullParserException( 1075 * "parser must be on START_TAG to read next text", this, null); 1076 * } 1077 * int eventType = next(); 1078 * if(eventType == TEXT) { 1079 * String result = getText(); 1080 * eventType = next(); 1081 * if(eventType != END_TAG) { 1082 * throw new XmlPullParserException( 1083 * "event TEXT it must be immediately followed by END_TAG", this, null); 1084 * } 1085 * return result; 1086 * } else if(eventType == END_TAG) { 1087 * return ""; 1088 * } else { 1089 * throw new XmlPullParserException( 1090 * "parser must be on START_TAG or TEXT to read text", this, null); 1091 * } 1092 * </pre> 1093 * 1094 * <p><strong>Warning:</strong> Prior to API level 14, the pull parser returned by {@code 1095 * android.util.Xml} did not always advance to the END_TAG event when this method was called. 1096 * Work around by using manually advancing after calls to nextText(): <pre> 1097 * String text = xpp.nextText(); 1098 * if (xpp.getEventType() != XmlPullParser.END_TAG) { 1099 * xpp.next(); 1100 * } 1101 * </pre> 1102 */ 1103 String nextText() throws XmlPullParserException, IOException; 1104 1105 /** 1106 * Call next() and return event if it is START_TAG or END_TAG 1107 * otherwise throw an exception. 1108 * It will skip whitespace TEXT before actual tag if any. 1109 * 1110 * <p>essentially it does this 1111 * <pre> 1112 * int eventType = next(); 1113 * if(eventType == TEXT && isWhitespace()) { // skip whitespace 1114 * eventType = next(); 1115 * } 1116 * if (eventType != START_TAG && eventType != END_TAG) { 1117 * throw new XmlPullParserException("expected start or end tag", this, null); 1118 * } 1119 * return eventType; 1120 * </pre> 1121 */ 1122 int nextTag() throws XmlPullParserException, IOException; 1123 1124 } 1125
