1# @ohos.xml (XML Parsing and Generation) 2 3The **XML** module provides a series of APIs for converting XML text into JavaScript objects and generating and parsing XML files. 4 5> **NOTE** 6> 7> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8 9 10## Modules to Import 11 12``` 13import xml from '@ohos.xml'; 14``` 15 16## XmlSerializer 17 18**XmlSerializer** provides APIs to generate an XML file. 19 20### constructor 21 22constructor(buffer: ArrayBuffer | DataView, encoding?: string) 23 24A constructor used to create an **XmlSerializer** instance. 25 26**System capability**: SystemCapability.Utils.Lang 27 28**Parameters** 29 30| Name | Type | Mandatory| Description | 31| -------- | --------------------------------- | ---- | ------------------------------------------------ | 32| buffer | ArrayBuffer \| DataView | Yes | **ArrayBuffer** or **DataView** for storing the XML information to set.| 33| encoding | string | No | Encoding format. The default value is **'utf-8'** (the only format currently supported). | 34 35**Example** 36 37```ts 38let arrayBuffer = new ArrayBuffer(2048); 39let thatSer = new xml.XmlSerializer(arrayBuffer, "utf-8"); 40thatSer.setDeclaration(); 41let result = '<?xml version="1.0" encoding="utf-8"?>'; 42let view = new Uint8Array(arrayBuffer); 43let view1 = ""; 44for (let i = 0; i < result.length; ++i) { 45 view1 = view1 + String.fromCodePoint(view[i]); 46} 47console.log(view1) // <?xml version="1.0" encoding="utf-8"?> 48``` 49 50 51### setAttributes 52 53setAttributes(name: string, value: string): void 54 55Sets an attribute. 56 57**System capability**: SystemCapability.Utils.Lang 58 59**Parameters** 60 61| Name| Type | Mandatory| Description | 62| ------ | ------ | ---- | --------------- | 63| name | string | Yes | Key of the attribute. | 64| value | string | Yes | Value of the attribute.| 65 66**Example** 67 68```ts 69const MY_MAX = 2048; 70let arrayBuffer = new ArrayBuffer(MY_MAX); 71let thatSer = new xml.XmlSerializer(arrayBuffer); 72thatSer.startElement("note"); 73thatSer.setAttributes("importance1", "high1"); 74thatSer.endElement(); 75let result = '<note importance1="high1"/>'; 76let view = new Uint8Array(arrayBuffer); 77let view1 = ""; 78for (let i = 0; i < result.length; ++i) { 79 view1 = view1 + String.fromCodePoint(view[i]); 80} 81console.log(view1) // <note importance1="high1"/> 82``` 83 84 85### addEmptyElement 86 87addEmptyElement(name: string): void 88 89Adds an empty element. 90 91**System capability**: SystemCapability.Utils.Lang 92 93**Parameters** 94 95| Name| Type | Mandatory| Description | 96| ------ | ------ | ---- | ------------------ | 97| name | string | Yes | Name of the empty element to add.| 98 99**Example** 100 101```ts 102const MY_MAX = 2048; 103let arrayBuffer = new ArrayBuffer(MY_MAX); 104let thatSer = new xml.XmlSerializer(arrayBuffer); 105thatSer.addEmptyElement("d"); 106let result = '<d/>'; 107let view = new Uint8Array(arrayBuffer); 108let view1 = ""; 109for (let i = 0; i < result.length; ++i) { 110 view1 = view1 + String.fromCodePoint(view[i]); 111} 112console.log(view1) // <d/> 113``` 114 115 116### setDeclaration 117 118setDeclaration(): void 119 120Sets a file declaration with encoding. 121 122**System capability**: SystemCapability.Utils.Lang 123 124**Example** 125 126```ts 127const MY_MAX = 2048; 128let arrayBuffer = new ArrayBuffer(MY_MAX); 129let thatSer = new xml.XmlSerializer(arrayBuffer); 130thatSer.setDeclaration(); 131thatSer.setNamespace("h", "http://www.w3.org/TR/html4/"); 132thatSer.startElement("note"); 133thatSer.endElement(); 134let result = '<?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/>'; 135let view = new Uint8Array(arrayBuffer); 136let view1 = ""; 137for (let i = 0; i < result.length; ++i) { 138 view1 = view1 + String.fromCodePoint(view[i]); 139} 140console.log(view1) 141// <?xml version="1.0" encoding="utf-8"?> 142// <h:note xmlns:h="http://www.w3.org/TR/html4/"/> 143``` 144 145 146### startElement 147 148startElement(name: string): void 149 150Writes the start tag based on the given element name. 151 152**System capability**: SystemCapability.Utils.Lang 153 154**Parameters** 155 156| Name| Type | Mandatory| Description | 157| ------ | ------ | ---- | ------------------ | 158| name | string | Yes | Name of the element.| 159 160**Example** 161 162```ts 163const MY_MAX = 2048; 164let arrayBuffer = new ArrayBuffer(MY_MAX); 165let thatSer = new xml.XmlSerializer(arrayBuffer); 166thatSer.setDeclaration(); 167thatSer.setNamespace("h", "http://www.w3.org/TR/html4/"); 168thatSer.startElement("note"); 169thatSer.endElement(); 170let result = '<?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/>'; 171let view = new Uint8Array(arrayBuffer); 172let view1 = ""; 173for (let i = 0; i < result.length; ++i) { 174 view1 = view1 + String.fromCodePoint(view[i]); 175} 176console.log(JSON.stringify(view1)) // <?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/> 177``` 178 179### endElement 180 181endElement(): void 182 183Writes the end tag of the element. 184 185**System capability**: SystemCapability.Utils.Lang 186 187**Example** 188 189```ts 190const MY_MAX = 2048; 191let arrayBuffer = new ArrayBuffer(MY_MAX); 192let thatSer = new xml.XmlSerializer(arrayBuffer); 193thatSer.setDeclaration(); 194thatSer.setNamespace("h", "http://www.w3.org/TR/html4/"); 195thatSer.startElement("note"); 196thatSer.endElement(); 197let result = '<?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/>'; 198let view = new Uint8Array(arrayBuffer); 199let view1 = ""; 200for (let i = 0; i < result.length; ++i) { 201 view1 = view1 + String.fromCodePoint(view[i]); 202} 203console.log(JSON.stringify(view1)) // <?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/> 204``` 205 206 207### setNamespace 208 209setNamespace(prefix: string, namespace: string): void 210 211Sets the namespace for an element tag. 212 213**System capability**: SystemCapability.Utils.Lang 214 215**Parameters** 216 217| Name | Type | Mandatory| Description | 218| --------- | ------ | ---- | ------------------------------ | 219| prefix | string | Yes | Prefix of the element and its child elements. | 220| namespace | string | Yes | Namespace to set.| 221 222**Example** 223 224```ts 225const MY_MAX = 2048; 226let arrayBuffer = new ArrayBuffer(MY_MAX); 227let thatSer = new xml.XmlSerializer(arrayBuffer); 228thatSer.setDeclaration(); 229thatSer.setNamespace("h", "http://www.w3.org/TR/html4/"); 230thatSer.startElement("note"); 231thatSer.endElement(); 232let result = '<?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/>'; 233let view = new Uint8Array(arrayBuffer); 234let view1 = ""; 235for (let i = 0; i < result.length; ++i) { 236 view1 = view1 + String.fromCodePoint(view[i]); 237} 238console.log(JSON.stringify(view1)) // <?xml version="1.0" encoding="utf-8"?>\r\n<h:note xmlns:h="http://www.w3.org/TR/html4/"/> 239``` 240 241### setComment 242 243setComment(text: string): void 244 245Sets a comment. 246 247**System capability**: SystemCapability.Utils.Lang 248 249**Parameters** 250 251| Name| Type | Mandatory| Description | 252| ------ | ------ | ---- | -------------------- | 253| text | string | Yes | Comment to set.| 254 255**Example** 256 257```ts 258const MY_MAX = 2048; 259let arrayBuffer = new ArrayBuffer(MY_MAX); 260let thatSer = new xml.XmlSerializer(arrayBuffer); 261thatSer.setComment("Hello, World!"); 262let result = '<!--Hello, World!-->'; 263let view = new Uint8Array(arrayBuffer); 264let view1 = ""; 265for (let i = 0; i < result.length; ++i) { 266 view1 = view1 + String.fromCodePoint(view[i]); 267} 268console.log(view1) // <!--Hello, World!--> 269``` 270 271 272### setCDATA 273 274setCDATA(text: string): void 275 276Sets CDATA data. 277 278**System capability**: SystemCapability.Utils.Lang 279 280**Parameters** 281 282| Name| Type | Mandatory| Description | 283| ------ | ------ | ---- | ----------------- | 284| text | string | Yes | CDATA data to set.| 285 286**Example** 287 288```ts 289const MY_MAX = 2048; 290let arrayBuffer = new ArrayBuffer(MY_MAX); 291let thatSer = new xml.XmlSerializer(arrayBuffer); 292thatSer.setCDATA('root SYSTEM') 293let result = '<![CDATA[root SYSTEM]]>'; 294let view = new Uint8Array(arrayBuffer); 295let view1 = ""; 296for (let i = 0; i < result.length; ++i) { 297 view1 = view1 + String.fromCodePoint(view[i]); 298} 299console.log(view1) // <![CDATA[root SYSTEM]]> 300``` 301 302 303### setText 304 305setText(text: string): void 306 307Sets a tag value. 308 309**System capability**: SystemCapability.Utils.Lang 310 311**Parameters** 312 313| Name| Type | Mandatory| Description | 314| ------ | ------ | ---- | ---------------- | 315| text | string | Yes | Tag value to set, which is the content of the **text** attribute.| 316 317**Example** 318 319```ts 320const MY_MAX = 2048; 321let arrayBuffer = new ArrayBuffer(MY_MAX); 322let thatSer = new xml.XmlSerializer(arrayBuffer); 323thatSer.startElement("note"); 324thatSer.setAttributes("importance", "high"); 325thatSer.setText("Happy1"); 326thatSer.endElement(); 327let result = '<note importance="high">Happy1</note>'; 328let view = new Uint8Array(arrayBuffer); 329let view1 = ""; 330for (let i = 0; i < result.length; ++i) { 331 view1 = view1 + String.fromCodePoint(view[i]); 332} 333console.log(view1) // <note importance="high">Happy1</note> 334``` 335 336 337### setDocType 338 339setDocType(text: string): void 340 341Sets a document type. 342 343**System capability**: SystemCapability.Utils.Lang 344 345**Parameters** 346 347| Name| Type | Mandatory| Description | 348| ------ | ------ | ---- | ------------------- | 349| text | string | Yes | Content of **DocType** to set.| 350 351**Example** 352 353```ts 354const MY_MAX = 2048; 355let arrayBuffer = new ArrayBuffer(MY_MAX); 356let thatSer = new xml.XmlSerializer(arrayBuffer); 357thatSer.setDocType('root SYSTEM "http://www.test.org/test.dtd"'); 358let result = '<!DOCTYPE root SYSTEM "http://www.test.org/test.dtd">'; 359let view = new Uint8Array(arrayBuffer); 360let view1 = ""; 361for (let i = 0; i < result.length; ++i) { 362 view1 = view1 + String.fromCodePoint(view[i]); 363} 364console.log(view1) // <!DOCTYPE root SYSTEM "http://www.test.org/test.dtd"> 365``` 366 367 368## XmlPullParser 369 370Implements XML file parsing. 371 372### constructor 373 374constructor(buffer: ArrayBuffer | DataView, encoding?: string) 375 376Creates and returns an **XmlPullParser** object. 377 378**System capability**: SystemCapability.Utils.Lang 379 380**Parameters** 381 382| Name | Type | Mandatory| Description | 383| -------- | --------------------------------- | ---- | ------------------------------------------ | 384| buffer | ArrayBuffer \| DataView | Yes | XML text information to be parsed.| 385| encoding | string | No | Encoding format. The default value is **'utf-8'** (the only format currently supported). | 386 387**Example** 388 389```ts 390import util from '@ohos.util'; 391 392let strXml = 393 '<?xml version="1.0" encoding="utf-8"?>' + 394 '<!DOCTYPE note [\n<!ENTITY foo "baa">]>' + 395 '<note importance="high" logged="true">' + 396 ' <![CDATA[\r\nfuncrion matchwo(a,6)\r\n{\r\nreturn 1;\r\n}\r\n]]>' + 397 ' <!--Hello, World!-->' + 398 ' <company>John & Hans</company>' + 399 ' <title>Happy</title>' + 400 ' <title>Happy</title>' + 401 ' <lens>Work</lens>' + 402 ' <lens>Play</lens>' + 403 ' <?go there?>' + 404 ' <a><b/></a>' + 405 ' <h:table xmlns:h="http://www.w3.org/TR/html4/">' + 406 ' <h:tr>' + 407 ' <h:td>Apples</h:td>' + 408 ' <h:td>Bananas</h:td>' + 409 ' </h:tr>' + 410 ' </h:table>' + 411 '</note>'; 412let textEncoder = new util.TextEncoder(); 413let arrbuffer = textEncoder.encodeInto(strXml); 414let that = new xml.XmlPullParser(arrbuffer.buffer, 'UTF-8'); 415let str1 = ''; 416function func1(name: string, value: string) { 417 str1 += name + value; 418 return true; 419} 420let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tagValueCallbackFunction:func1} 421that.parse(options); 422console.log(str1) 423// note [<!ENTITY foo "baa">]note funcrion matchwo(a,6){return 1;} Hello, World! companyJohn amp;amp; Hanscompany titleHappytitle titleHappytitle lensWorklens lensPlaylens go there abba h:table h:tr h:tdApplesh:td h:tdBananash:td h:tr h:tablenote 424``` 425 426 427### parse 428 429parse(option: ParseOptions): void 430 431Parses XML information. 432 433**System capability**: SystemCapability.Utils.Lang 434 435**Parameters** 436 437| Name| Type | Mandatory| Description | 438| ------ | ----------------------------- | ---- | -------------------------------- | 439| option | [ParseOptions](#parseoptions) | Yes | Options for controlling and obtaining the parsed information.| 440 441**Example** 442 443```ts 444import util from '@ohos.util'; 445 446let strXml = 447 '<?xml version="1.0" encoding="utf-8"?>' + 448 '<note importance="high" logged="true">' + 449 ' <title>Happy</title>' + 450 ' <todo>Work</todo>' + 451 ' <todo>Play</todo>' + 452 '</note>'; 453let textEncoder = new util.TextEncoder(); 454let arrbuffer = textEncoder.encodeInto(strXml); 455let that = new xml.XmlPullParser(arrbuffer.buffer); 456let str = ""; 457function func(key: xml.EventType, value: xml.ParseInfo) { 458 str += 'key:' + key + ' value:' + value.getDepth() + ' '; 459 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 460} 461let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 462that.parse(options); 463console.log(str); 464// Output: 465// key:0 value:0 key:2 value:1 key:10 value:1 key:2 value:2 key:4 value:2 key:3 value:2 key:10 value:1 key:2 value:2 key:4 value:2 key:3 value:2 key:10 value:1 key:2 value:2 key:4 value:2 key:3 value:2 key:3 value:1 key:1 value:0 466// Note: 467// key indicates the event type, and value indicates the parsing depth. You can learn the specific parsed event based on EVENTTYPE. In this example, key: value means: 468// 0(START_DOCUMENT):0 (START_DOCUMENT is being parsed, and the depth is 0), 2(START_TAG):1 (START_TAG is being parsed, and the depth is 1), 10(WHITESPACE):1 (WHITESPACE is being parsed, and the depth is 1), 2(START_TAG):2 (START_TAG is being parsed, and the depth is 2), ... 469``` 470 471 472## ParseOptions 473 474Defines the XML parsing options. 475 476**System capability**: SystemCapability.Utils.Lang 477 478 479| Name | Type | Mandatory| Description | 480| ------------------------------ | ------------------------------------------------------------ | ---- | --------------------------------------- | 481| supportDoctype | boolean | No | Whether to ignore the document type. The default value is **false**, indicating that the document type is parsed.| 482| ignoreNameSpace | boolean | No | Whether to ignore the namespace. The default value is **false**, indicating that the namespace is parsed.| 483| tagValueCallbackFunction | (name: string, value: string) => boolean | No | Callback used to return **tagValue** for parsing the tag and tag value. The default value is **null**, indicating that the tag and tag value are not parsed. | 484| attributeValueCallbackFunction | (name: string, value: string) => boolean | No | Callback used to return **attributeValue** for parsing the attribute and attribute value. The default value is **null**, indicating that the attribute and attribute value are not parsed.| 485| tokenValueCallbackFunction | (eventType: [EventType](#eventtype), value: [ParseInfo](#parseinfo)) => boolean | No | Callback used to return **tokenValue** for parsing the [EventType](#eventtype) and [ParseInfo](#parseinfo) attributes. The default value is **null**, indicating that the **EventType** and **ParseInfo** attribute are not parsed.| 486 487## ParseInfo 488 489Provides APIs to manage the parsed XML information. 490 491 492### getColumnNumber 493 494getColumnNumber(): number 495 496Obtains the column line number, starting from 1. 497 498**System capability**: SystemCapability.Utils.Lang 499 500**Return value** 501 502| Type | Description | 503| ------ | -------------- | 504| number | Column number obtained.| 505 506**Example** 507 508```ts 509import util from '@ohos.util'; 510 511let strXml = 512 '<?xml version="1.0" encoding="utf-8"?>' + 513 '<note importance="high" logged="true">' + 514 ' <title>Happy</title>' + 515 ' <todo>Work</todo>' + 516 ' <todo>Play</todo>' + 517 '</note>'; 518let textEncoder = new util.TextEncoder(); 519let arrbuffer = textEncoder.encodeInto(strXml); 520let that = new xml.XmlPullParser(arrbuffer.buffer); 521let str = ""; 522function func(key: xml.EventType, value: xml.ParseInfo) { 523 str += 'key:' + key + ' value:' + value.getColumnNumber() + ' '; 524 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 525} 526let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 527that.parse(options); 528console.log(str); 529// Output: 530// key:0 value:1 key:2 value:77 key:10 value:81 key:2 value:88 key:4 value:93 key:3 value:101 key:10 value:105 key:2 value:111 key:4 value:115 key:3 value:122 key:10 value:126 key:2 value:132 key:4 value:136 key:3 value:143 key:3 value:150 key:1 value:299 531``` 532 533### getDepth 534 535getDepth(): number 536 537Obtains the depth of this element. 538 539**System capability**: SystemCapability.Utils.Lang 540 541**Return value** 542 543| Type | Description | 544| ------ | -------------------- | 545| number | Depth obtained.| 546 547**Example** 548 549```ts 550import util from '@ohos.util'; 551 552let strXml = 553 '<?xml version="1.0" encoding="utf-8"?>' + 554 '<note importance="high" logged="true">' + 555 ' <title>Happy</title>' + 556 ' <todo>Work</todo>' + 557 ' <todo>Play</todo>' + 558 '</note>'; 559let textEncoder = new util.TextEncoder(); 560let arrbuffer = textEncoder.encodeInto(strXml); 561let that = new xml.XmlPullParser(arrbuffer.buffer); 562let str = ""; 563function func(key: xml.EventType, value: xml.ParseInfo) { 564 str += 'key:' + key + ' value:' + value.getDepth() + ' '; 565 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 566} 567let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 568that.parse(options); 569console.log(str); 570// Output: 571// key:0 value:0 key:2 value:1 key:10 value:1 key:2 value:2 key:4 value:2 key:3 value:2 key:10 value:1 key:2 value:2 key:4 value:2 key:3 value:2 key:10 value:1 key:2 value:2 key:4 value:2 key:3 value:2 key:3 value:1 key:1 value:0 572// Note: 573// key indicates the event type, and value indicates the parsing depth. You can learn the specific parsed event based on EVENTTYPE. In this example, key: value means: 574// 0(START_DOCUMENT):0 (START_DOCUMENT is being parsed, and the depth is 0), 2(START_TAG):1 (START_TAG is being parsed, and the depth is 1), 10(WHITESPACE):1 (WHITESPACE is being parsed, and the depth is 1), 2(START_TAG):2 (START_TAG is being parsed, and the depth is 2), ... 575``` 576 577### getLineNumber 578 579getLineNumber(): number 580 581Obtains the current line number, starting from 1. 582 583**System capability**: SystemCapability.Utils.Lang 584 585**Return value** 586 587| Type | Description | 588| ------ | -------------- | 589| number | Line number obtained.| 590 591**Example** 592 593```ts 594import util from '@ohos.util'; 595 596let strXml = 597 '<?xml version="1.0" encoding="utf-8"?>' + 598 '<note importance="high" logged="true">' + 599 ' <title>Happy</title>' + 600 ' <todo>Work</todo>' + 601 ' <todo>Play</todo>' + 602 '</note>'; 603let textEncoder = new util.TextEncoder(); 604let arrbuffer = textEncoder.encodeInto(strXml); 605let that = new xml.XmlPullParser(arrbuffer.buffer); 606let str = ""; 607function func(key: xml.EventType, value: xml.ParseInfo) { 608 str += 'key:' + key + ' value:' + value.getLineNumber() + ' '; 609 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 610} 611let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 612that.parse(options); 613console.log(str); 614// Output: 615// key:0 value:1 key:2 value:1 key:10 value:1 key:2 value:1 key:4 value:1 key:3 value:1 key:10 value:1 key:2 value:1 key:4 value:1 key:3 value:1 key:10 value:1 key:2 value:1 key:4 value:1 key:3 value:1 key:3 value:1 key:1 value:1 616``` 617 618### getName 619 620getName(): string 621 622Obtains the name of this element. 623 624**System capability**: SystemCapability.Utils.Lang 625 626**Return value** 627 628| Type | Description | 629| ------ | ------------------ | 630| string | Element name obtained.| 631 632**Example** 633 634```ts 635import util from '@ohos.util'; 636 637let strXml = 638 '<?xml version="1.0" encoding="utf-8"?>' + 639 '<note importance="high" logged="true">' + 640 ' <title>Happy</title>' + 641 ' <todo>Work</todo>' + 642 ' <todo>Play</todo>' + 643 '</note>'; 644let textEncoder = new util.TextEncoder(); 645let arrbuffer = textEncoder.encodeInto(strXml); 646let that = new xml.XmlPullParser(arrbuffer.buffer); 647let str = ""; 648function func(key: xml.EventType, value: xml.ParseInfo) { 649 str += 'key:' + key + ' value:' + value.getName() + ' '; 650 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 651} 652let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 653that.parse(options); 654console.log(str); 655// Output: 656// key:0 value: key:2 value:note key:10 value: key:2 value:title key:4 value: key:3 value:title key:10 value: key:2 value:todo key:4 value: key:3 value:todo key:10 value: key:2 value:todo key:4 value: key:3 value:todo key:3 value:note key:1 value: 657``` 658### getNamespace 659 660getNamespace(): string 661 662Obtains the namespace of this element. 663 664**System capability**: SystemCapability.Utils.Lang 665 666**Return value** 667 668| Type | Description | 669| ------ | ------------------------ | 670| string | Namespace obtained.| 671 672**Example** 673 674```ts 675import util from '@ohos.util'; 676 677let strXml = 678 '<?xml version="1.0" encoding="utf-8"?>' + 679 '<note importance="high" logged="true">' + 680 ' <title>Happy</title>' + 681 ' <todo>Work</todo>' + 682 ' <todo>Play</todo>' + 683 '</note>'; 684let textEncoder = new util.TextEncoder(); 685let arrbuffer = textEncoder.encodeInto(strXml); 686let that = new xml.XmlPullParser(arrbuffer.buffer); 687let str = ""; 688function func(key: xml.EventType, value: xml.ParseInfo) { 689 str += 'key:' + key + ' value:' + value.getNamespace() + ' '; 690 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 691} 692let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 693that.parse(options); 694console.log(str); 695// Output: 696// key:0 value: key:2 value: key:10 value: key:2 value: key:4 value: key:3 value: key:10 value: key:2 value: key:4 value: key:3 value: key:10 value: key:2 value: key:4 value: key:3 value: key:3 value: key:1 value: 697``` 698### getPrefix 699 700getPrefix(): string 701 702Obtains the prefix of this element. 703 704**System capability**: SystemCapability.Utils.Lang 705 706**Return value** 707 708| Type | Description | 709| ------ | ------------------ | 710| string | Element prefix obtained.| 711 712**Example** 713 714```ts 715import util from '@ohos.util'; 716 717let strXml = 718 '<?xml version="1.0" encoding="utf-8"?>' + 719 '<note importance="high" logged="true">' + 720 ' <title>Happy</title>' + 721 ' <todo>Work</todo>' + 722 ' <todo>Play</todo>' + 723 '</note>'; 724let textEncoder = new util.TextEncoder(); 725let arrbuffer = textEncoder.encodeInto(strXml); 726let that = new xml.XmlPullParser(arrbuffer.buffer); 727let str = ""; 728function func(key: xml.EventType, value: xml.ParseInfo) { 729 str += 'key:' + key + ' value:' + value.getPrefix() + ' '; 730 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 731} 732let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 733that.parse(options); 734console.log(str); 735// Output: 736// key:0 value: key:2 value: key:10 value: key:2 value: key:4 value: key:3 value: key:10 value: key:2 value: key:4 value: key:3 value: key:10 value: key:2 value: key:4 value: key:3 value: key:3 value: key:1 value: 737``` 738 739### getText 740 741getText(): string 742 743Obtains the text of the current event. 744 745**System capability**: SystemCapability.Utils.Lang 746 747**Return value** 748 749| Type | Description | 750| ------ | ------------------------ | 751| string | Text content obtained.| 752 753**Example** 754 755```ts 756import util from '@ohos.util'; 757 758let strXml = 759 '<?xml version="1.0" encoding="utf-8"?>' + 760 '<note importance="high" logged="true">' + 761 ' <title>Happy</title>' + 762 ' <todo>Work</todo>' + 763 ' <todo>Play</todo>' + 764 '</note>'; 765let textEncoder = new util.TextEncoder(); 766let arrbuffer = textEncoder.encodeInto(strXml); 767let that = new xml.XmlPullParser(arrbuffer.buffer); 768let str = ""; 769function func(key: xml.EventType, value: xml.ParseInfo) { 770 str += ' key:' + key + ' value:' + value.getText() + ' '; 771 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 772} 773let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 774that.parse(options); 775console.log(str); 776// Output: 777// key:0 value: key:2 value: key:10 value: key:2 value: key:4 value:Happy key:3 value: key:10 value: key:2 value: key:4 value:Work key:3 value: key:10 value: key:2 value: key:4 value:Play key:3 value: key:3 value: key:1 value: 778``` 779### isEmptyElementTag 780 781isEmptyElementTag(): boolean 782 783Checks whether the current element is empty. 784 785**System capability**: SystemCapability.Utils.Lang 786 787**Return value** 788 789| Type | Description | 790| ------- | ---------------------------- | 791| boolean | Returns **true** if the element is empty; returns **false** otherwise.| 792 793**Example** 794 795```ts 796import util from '@ohos.util'; 797 798let strXml = 799 '<?xml version="1.0" encoding="utf-8"?>' + 800 '<note importance="high" logged="true">' + 801 ' <title>Happy</title>' + 802 ' <todo>Work</todo>' + 803 ' <todo>Play</todo>' + 804 '</note>'; 805let textEncoder = new util.TextEncoder(); 806let arrbuffer = textEncoder.encodeInto(strXml); 807let that = new xml.XmlPullParser(arrbuffer.buffer); 808let str = ""; 809function func(key: xml.EventType, value: xml.ParseInfo) { 810 str += 'key:' + key + ' value:' + value.isEmptyElementTag() + ' '; 811 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 812} 813let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 814that.parse(options); 815console.log(str); 816// Output: 817// key:0 value:false key:2 value:false key:10 value:false key:2 value:false key:4 value:false key:3 value:false key:10 value:false key:2 value:false key:4 value:false key:3 value:false key:10 value:false key:2 value:false key:4 value:false key:3 value:false key:3 value:false key:1 value:false 818``` 819### isWhitespace 820 821isWhitespace(): boolean 822 823Checks whether the current text event contains only whitespace characters. 824 825**System capability**: SystemCapability.Utils.Lang 826 827**Return value** 828 829| Type | Description | 830| ------- | -------------------------------------- | 831| boolean | Returns **true** if the text event contains only whitespace characters; returns **false** otherwise.| 832 833**Example** 834 835```ts 836import util from '@ohos.util'; 837 838let strXml = 839 '<?xml version="1.0" encoding="utf-8"?>' + 840 '<note importance="high" logged="true">' + 841 ' <title>Happy</title>' + 842 ' <todo>Work</todo>' + 843 ' <todo>Play</todo>' + 844 '</note>'; 845let textEncoder = new util.TextEncoder(); 846let arrbuffer = textEncoder.encodeInto(strXml); 847let that = new xml.XmlPullParser(arrbuffer.buffer); 848let str = ""; 849function func(key: xml.EventType, value: xml.ParseInfo) { 850 str += 'key:' + key + ' value:' + value.isWhitespace() + ' '; 851 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 852} 853let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 854that.parse(options); 855console.log(str); 856// Output: 857// key:0 value:true key:2 value:false key:10 value:true key:2 value:true key:4 value:false key:3 value:true key:10 value:true key:2 value:true key:4 value:false key:3 value:true key:10 value:true key:2 value:true key:4 value:false key:3 value:true key:3 value:true key:1 value:true 858``` 859### getAttributeCount 860 861getAttributeCount(): number 862 863Obtains the number of attributes for the current start tag. 864 865**System capability**: SystemCapability.Utils.Lang 866 867**Return value** 868| Type | Description | 869| ------ | ---------------------- | 870| number | Number of attributes obtained.| 871 872**Example** 873 874```ts 875import util from '@ohos.util'; 876 877let strXml = 878 '<?xml version="1.0" encoding="utf-8"?>' + 879 '<note importance="high" logged="true">' + 880 ' <title>Happy</title>' + 881 ' <todo>Work</todo>' + 882 ' <todo>Play</todo>' + 883 '</note>'; 884let textEncoder = new util.TextEncoder(); 885let arrbuffer = textEncoder.encodeInto(strXml); 886let that = new xml.XmlPullParser(arrbuffer.buffer); 887let str = ""; 888function func(key: xml.EventType, value: xml.ParseInfo) { 889 str += 'key:' + key + ' value:' + value.getAttributeCount() + ' '; 890 return true; // Determines whether to continually parse, which is used to continue or terminate parsing. 891} 892let options: xml.ParseOptions = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func} 893that.parse(options); 894console.log(str); 895// Output: 896// key:0 value:0 key:2 value:2 key:10 value:0 key:2 value:0 key:4 value:0 key:3 value:0 key:10 value:0 key:2 value:0 key:4 value:0 key:3 value:0 key:10 value:0 key:2 value:0 key:4 value:0 key:3 value:0 key:3 value:0 key:1 value:0 897``` 898 899## EventType 900 901Enumerates the event types. 902 903**System capability**: SystemCapability.Utils.Lang 904 905| Name | Value | Description | 906| ---------------- | ---- | --------------------- | 907| START_DOCUMENT | 0 | Start document event. | 908| END_DOCUMENT | 1 | End document event. | 909| START_TAG | 2 | Start tag event. | 910| END_TAG | 3 | End tag event. | 911| TEXT | 4 | Text event. | 912| CDSECT | 5 | CDATA section event. | 913| COMMENT | 6 | XML comment event. | 914| DOCDECL | 7 | XML document type declaration event.| 915| INSTRUCTION | 8 | XML processing instruction event.| 916| ENTITY_REFERENCE | 9 | Entity reference event. | 917| WHITESPACE | 10 | Whitespace character event. | 918