quick_xml/reader/ns_reader.rs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
//! A reader that manages namespace declarations found in the input and able
//! to resolve [qualified names] to [expanded names].
//!
//! [qualified names]: https://www.w3.org/TR/xml-names11/#dt-qualname
//! [expanded names]: https://www.w3.org/TR/xml-names11/#dt-expname
use std::borrow::Cow;
use std::fs::File;
use std::io::{BufRead, BufReader};
use std::ops::Deref;
use std::path::Path;
use crate::errors::Result;
use crate::events::Event;
use crate::name::{LocalName, NamespaceResolver, PrefixIter, QName, ResolveResult};
use crate::reader::{Config, Reader, Span, XmlSource};
/// A low level encoding-agnostic XML event reader that performs namespace resolution.
///
/// Consumes a [`BufRead`] and streams XML `Event`s.
pub struct NsReader<R> {
/// An XML reader
pub(super) reader: Reader<R>,
/// A buffer to manage namespaces
ns_resolver: NamespaceResolver,
/// We cannot pop data from the namespace stack until returned `Empty` or `End`
/// event will be processed by the user, so we only mark that we should that
/// in the next [`Self::read_event_impl()`] call.
pending_pop: bool,
}
/// Builder methods
impl<R> NsReader<R> {
/// Creates a `NsReader` that reads from a reader.
#[inline]
pub fn from_reader(reader: R) -> Self {
Self::new(Reader::from_reader(reader))
}
/// Returns reference to the parser configuration
#[inline]
pub const fn config(&self) -> &Config {
self.reader.config()
}
/// Returns mutable reference to the parser configuration
#[inline]
pub fn config_mut(&mut self) -> &mut Config {
self.reader.config_mut()
}
/// Returns all the prefixes currently declared except the default `xml` and `xmlns` namespaces.
///
/// # Examples
///
/// This example shows what results the returned iterator would return after
/// reading each event of a simple XML.
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::name::{Namespace, PrefixDeclaration};
/// use quick_xml::NsReader;
///
/// let src = "<root>
/// <a xmlns=\"a1\" xmlns:a=\"a2\">
/// <b xmlns=\"b1\" xmlns:b=\"b2\">
/// <c/>
/// </b>
/// <d/>
/// </a>
/// </root>";
/// let mut reader = NsReader::from_str(src);
/// reader.config_mut().trim_text(true);
/// // No prefixes at the beginning
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![]);
///
/// reader.read_resolved_event()?; // <root>
/// // No prefixes declared on root
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![]);
///
/// reader.read_resolved_event()?; // <a>
/// // Two prefixes declared on "a"
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![
/// (PrefixDeclaration::Default, Namespace(b"a1")),
/// (PrefixDeclaration::Named(b"a"), Namespace(b"a2"))
/// ]);
///
/// reader.read_resolved_event()?; // <b>
/// // The default prefix got overridden and new "b" prefix
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![
/// (PrefixDeclaration::Named(b"a"), Namespace(b"a2")),
/// (PrefixDeclaration::Default, Namespace(b"b1")),
/// (PrefixDeclaration::Named(b"b"), Namespace(b"b2"))
/// ]);
///
/// reader.read_resolved_event()?; // <c/>
/// // Still the same
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![
/// (PrefixDeclaration::Named(b"a"), Namespace(b"a2")),
/// (PrefixDeclaration::Default, Namespace(b"b1")),
/// (PrefixDeclaration::Named(b"b"), Namespace(b"b2"))
/// ]);
///
/// reader.read_resolved_event()?; // </b>
/// // Still the same
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![
/// (PrefixDeclaration::Named(b"a"), Namespace(b"a2")),
/// (PrefixDeclaration::Default, Namespace(b"b1")),
/// (PrefixDeclaration::Named(b"b"), Namespace(b"b2"))
/// ]);
///
/// reader.read_resolved_event()?; // <d/>
/// // </b> got closed so back to the prefixes declared on <a>
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![
/// (PrefixDeclaration::Default, Namespace(b"a1")),
/// (PrefixDeclaration::Named(b"a"), Namespace(b"a2"))
/// ]);
///
/// reader.read_resolved_event()?; // </a>
/// // Still the same
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![
/// (PrefixDeclaration::Default, Namespace(b"a1")),
/// (PrefixDeclaration::Named(b"a"), Namespace(b"a2"))
/// ]);
///
/// reader.read_resolved_event()?; // </root>
/// // <a> got closed
/// assert_eq!(reader.prefixes().collect::<Vec<_>>(), vec![]);
/// # quick_xml::Result::Ok(())
/// ```
#[inline]
pub const fn prefixes(&self) -> PrefixIter {
self.ns_resolver.iter()
}
}
/// Private methods
impl<R> NsReader<R> {
#[inline]
fn new(reader: Reader<R>) -> Self {
Self {
reader,
ns_resolver: NamespaceResolver::default(),
pending_pop: false,
}
}
fn read_event_impl<'i, B>(&mut self, buf: B) -> Result<Event<'i>>
where
R: XmlSource<'i, B>,
{
self.pop();
let event = self.reader.read_event_impl(buf);
self.process_event(event)
}
pub(super) fn pop(&mut self) {
if self.pending_pop {
self.ns_resolver.pop();
self.pending_pop = false;
}
}
pub(super) fn process_event<'i>(&mut self, event: Result<Event<'i>>) -> Result<Event<'i>> {
match event {
Ok(Event::Start(e)) => {
self.ns_resolver.push(&e)?;
Ok(Event::Start(e))
}
Ok(Event::Empty(e)) => {
self.ns_resolver.push(&e)?;
// notify next `read_event_impl()` invocation that it needs to pop this
// namespace scope
self.pending_pop = true;
Ok(Event::Empty(e))
}
Ok(Event::End(e)) => {
// notify next `read_event_impl()` invocation that it needs to pop this
// namespace scope
self.pending_pop = true;
Ok(Event::End(e))
}
e => e,
}
}
pub(super) fn resolve_event<'i>(
&mut self,
event: Result<Event<'i>>,
) -> Result<(ResolveResult, Event<'i>)> {
match event {
Ok(Event::Start(e)) => Ok((self.ns_resolver.find(e.name()), Event::Start(e))),
Ok(Event::Empty(e)) => Ok((self.ns_resolver.find(e.name()), Event::Empty(e))),
Ok(Event::End(e)) => Ok((self.ns_resolver.find(e.name()), Event::End(e))),
Ok(e) => Ok((ResolveResult::Unbound, e)),
Err(e) => Err(e),
}
}
}
/// Getters
impl<R> NsReader<R> {
/// Consumes `NsReader` returning the underlying reader
///
/// See the [`Reader::into_inner`] for examples
#[inline]
pub fn into_inner(self) -> R {
self.reader.into_inner()
}
/// Gets a mutable reference to the underlying reader.
pub fn get_mut(&mut self) -> &mut R {
self.reader.get_mut()
}
/// Resolves a potentially qualified **element name** or **attribute name**
/// into _(namespace name, local name)_.
///
/// _Qualified_ names have the form `prefix:local-name` where the `prefix`
/// is defined on any containing XML element via `xmlns:prefix="the:namespace:uri"`.
/// The namespace prefix can be defined on the same element as the name in question.
///
/// The method returns following results depending on the `name` shape,
/// `attribute` flag and the presence of the default namespace:
///
/// |attribute|`xmlns="..."`|QName |ResolveResult |LocalName
/// |---------|-------------|-------------------|-----------------------|------------
/// |`true` |Not defined |`local-name` |[`Unbound`] |`local-name`
/// |`true` |Defined |`local-name` |[`Unbound`] |`local-name`
/// |`true` |_any_ |`prefix:local-name`|[`Bound`] / [`Unknown`]|`local-name`
/// |`false` |Not defined |`local-name` |[`Unbound`] |`local-name`
/// |`false` |Defined |`local-name` |[`Bound`] (default) |`local-name`
/// |`false` |_any_ |`prefix:local-name`|[`Bound`] / [`Unknown`]|`local-name`
///
/// If you want to clearly indicate that name that you resolve is an element
/// or an attribute name, you could use [`resolve_attribute()`] or [`resolve_element()`]
/// methods.
///
/// # Lifetimes
///
/// - `'n`: lifetime of a name. Returned local name will be bound to the same
/// lifetime as the name in question.
/// - returned namespace name will be bound to the reader itself
///
/// [`Bound`]: ResolveResult::Bound
/// [`Unbound`]: ResolveResult::Unbound
/// [`Unknown`]: ResolveResult::Unknown
/// [`resolve_attribute()`]: Self::resolve_attribute()
/// [`resolve_element()`]: Self::resolve_element()
#[inline]
pub fn resolve<'n>(&self, name: QName<'n>, attribute: bool) -> (ResolveResult, LocalName<'n>) {
self.ns_resolver.resolve(name, !attribute)
}
/// Resolves a potentially qualified **element name** into _(namespace name, local name)_.
///
/// _Qualified_ element names have the form `prefix:local-name` where the
/// `prefix` is defined on any containing XML element via `xmlns:prefix="the:namespace:uri"`.
/// The namespace prefix can be defined on the same element as the element
/// in question.
///
/// _Unqualified_ elements inherits the current _default namespace_.
///
/// The method returns following results depending on the `name` shape and
/// the presence of the default namespace:
///
/// |`xmlns="..."`|QName |ResolveResult |LocalName
/// |-------------|-------------------|-----------------------|------------
/// |Not defined |`local-name` |[`Unbound`] |`local-name`
/// |Defined |`local-name` |[`Bound`] (default) |`local-name`
/// |_any_ |`prefix:local-name`|[`Bound`] / [`Unknown`]|`local-name`
///
/// # Lifetimes
///
/// - `'n`: lifetime of an element name. Returned local name will be bound
/// to the same lifetime as the name in question.
/// - returned namespace name will be bound to the reader itself
///
/// # Examples
///
/// This example shows how you can resolve qualified name into a namespace.
/// Note, that in the code like this you do not need to do that manually,
/// because the namespace resolution result returned by the [`read_resolved_event()`].
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::Event;
/// use quick_xml::name::{Namespace, QName, ResolveResult::*};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str("<tag xmlns='root namespace'/>");
///
/// match reader.read_event().unwrap() {
/// Event::Empty(e) => assert_eq!(
/// reader.resolve_element(e.name()),
/// (Bound(Namespace(b"root namespace")), QName(b"tag").into())
/// ),
/// _ => unreachable!(),
/// }
/// ```
///
/// [`Bound`]: ResolveResult::Bound
/// [`Unbound`]: ResolveResult::Unbound
/// [`Unknown`]: ResolveResult::Unknown
/// [`read_resolved_event()`]: Self::read_resolved_event
#[inline]
pub fn resolve_element<'n>(&self, name: QName<'n>) -> (ResolveResult, LocalName<'n>) {
self.ns_resolver.resolve(name, true)
}
/// Resolves a potentially qualified **attribute name** into _(namespace name, local name)_.
///
/// _Qualified_ attribute names have the form `prefix:local-name` where the
/// `prefix` is defined on any containing XML element via `xmlns:prefix="the:namespace:uri"`.
/// The namespace prefix can be defined on the same element as the attribute
/// in question.
///
/// _Unqualified_ attribute names do *not* inherit the current _default namespace_.
///
/// The method returns following results depending on the `name` shape and
/// the presence of the default namespace:
///
/// |`xmlns="..."`|QName |ResolveResult |LocalName
/// |-------------|-------------------|-----------------------|------------
/// |Not defined |`local-name` |[`Unbound`] |`local-name`
/// |Defined |`local-name` |[`Unbound`] |`local-name`
/// |_any_ |`prefix:local-name`|[`Bound`] / [`Unknown`]|`local-name`
///
/// # Lifetimes
///
/// - `'n`: lifetime of an attribute name. Returned local name will be bound
/// to the same lifetime as the name in question.
/// - returned namespace name will be bound to the reader itself
///
/// # Examples
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::Event;
/// use quick_xml::name::{Namespace, QName, ResolveResult::*};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str("
/// <tag one='1'
/// p:two='2'
/// xmlns='root namespace'
/// xmlns:p='other namespace'/>
/// ");
/// reader.config_mut().trim_text(true);
///
/// match reader.read_event().unwrap() {
/// Event::Empty(e) => {
/// let mut iter = e.attributes();
///
/// // Unlike elements, attributes without explicit namespace
/// // not bound to any namespace
/// let one = iter.next().unwrap().unwrap();
/// assert_eq!(
/// reader.resolve_attribute(one.key),
/// (Unbound, QName(b"one").into())
/// );
///
/// let two = iter.next().unwrap().unwrap();
/// assert_eq!(
/// reader.resolve_attribute(two.key),
/// (Bound(Namespace(b"other namespace")), QName(b"two").into())
/// );
/// }
/// _ => unreachable!(),
/// }
/// ```
///
/// [`Bound`]: ResolveResult::Bound
/// [`Unbound`]: ResolveResult::Unbound
/// [`Unknown`]: ResolveResult::Unknown
#[inline]
pub fn resolve_attribute<'n>(&self, name: QName<'n>) -> (ResolveResult, LocalName<'n>) {
self.ns_resolver.resolve(name, false)
}
}
impl<R: BufRead> NsReader<R> {
/// Reads the next event into given buffer.
///
/// This method manages namespaces but doesn't resolve them automatically.
/// You should call [`resolve_element()`] if you want to get a namespace.
///
/// You also can use [`read_resolved_event_into()`] instead if you want to resolve
/// namespace as soon as you get an event.
///
/// # Examples
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::Event;
/// use quick_xml::name::{Namespace, ResolveResult::*};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <x:tag1 xmlns:x="www.xxxx" xmlns:y="www.yyyy" att1 = "test">
/// <y:tag2><!--Test comment-->Test</y:tag2>
/// <y:tag2>Test 2</y:tag2>
/// </x:tag1>
/// "#);
/// reader.config_mut().trim_text(true);
///
/// let mut count = 0;
/// let mut buf = Vec::new();
/// let mut txt = Vec::new();
/// loop {
/// match reader.read_event_into(&mut buf).unwrap() {
/// Event::Start(e) => {
/// count += 1;
/// let (ns, local) = reader.resolve_element(e.name());
/// match local.as_ref() {
/// b"tag1" => assert_eq!(ns, Bound(Namespace(b"www.xxxx"))),
/// b"tag2" => assert_eq!(ns, Bound(Namespace(b"www.yyyy"))),
/// _ => unreachable!(),
/// }
/// }
/// Event::Text(e) => {
/// txt.push(e.unescape().unwrap().into_owned())
/// }
/// Event::Eof => break,
/// _ => (),
/// }
/// buf.clear();
/// }
/// assert_eq!(count, 3);
/// assert_eq!(txt, vec!["Test".to_string(), "Test 2".to_string()]);
/// ```
///
/// [`resolve_element()`]: Self::resolve_element
/// [`read_resolved_event_into()`]: Self::read_resolved_event_into
#[inline]
pub fn read_event_into<'b>(&mut self, buf: &'b mut Vec<u8>) -> Result<Event<'b>> {
self.read_event_impl(buf)
}
/// Reads the next event into given buffer and resolves its namespace (if applicable).
///
/// Namespace is resolved only for [`Start`], [`Empty`] and [`End`] events.
/// For all other events the concept of namespace is not defined, so
/// a [`ResolveResult::Unbound`] is returned.
///
/// If you are not interested in namespaces, you can use [`read_event_into()`]
/// which will not automatically resolve namespaces for you.
///
/// # Examples
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::Event;
/// use quick_xml::name::{Namespace, QName, ResolveResult::*};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <x:tag1 xmlns:x="www.xxxx" xmlns:y="www.yyyy" att1 = "test">
/// <y:tag2><!--Test comment-->Test</y:tag2>
/// <y:tag2>Test 2</y:tag2>
/// </x:tag1>
/// "#);
/// reader.config_mut().trim_text(true);
///
/// let mut count = 0;
/// let mut buf = Vec::new();
/// let mut txt = Vec::new();
/// loop {
/// match reader.read_resolved_event_into(&mut buf).unwrap() {
/// (Bound(Namespace(b"www.xxxx")), Event::Start(e)) => {
/// count += 1;
/// assert_eq!(e.local_name(), QName(b"tag1").into());
/// }
/// (Bound(Namespace(b"www.yyyy")), Event::Start(e)) => {
/// count += 1;
/// assert_eq!(e.local_name(), QName(b"tag2").into());
/// }
/// (_, Event::Start(_)) => unreachable!(),
///
/// (_, Event::Text(e)) => {
/// txt.push(e.unescape().unwrap().into_owned())
/// }
/// (_, Event::Eof) => break,
/// _ => (),
/// }
/// buf.clear();
/// }
/// assert_eq!(count, 3);
/// assert_eq!(txt, vec!["Test".to_string(), "Test 2".to_string()]);
/// ```
///
/// [`Start`]: Event::Start
/// [`Empty`]: Event::Empty
/// [`End`]: Event::End
/// [`read_event_into()`]: Self::read_event_into
#[inline]
pub fn read_resolved_event_into<'b>(
&mut self,
buf: &'b mut Vec<u8>,
) -> Result<(ResolveResult, Event<'b>)> {
let event = self.read_event_impl(buf);
self.resolve_event(event)
}
/// Reads until end element is found using provided buffer as intermediate
/// storage for events content. This function is supposed to be called after
/// you already read a [`Start`] event.
///
/// Returns a span that cover content between `>` of an opening tag and `<` of
/// a closing tag or an empty slice, if [`expand_empty_elements`] is set and
/// this method was called after reading expanded [`Start`] event.
///
/// Manages nested cases where parent and child elements have the _literally_
/// same name.
///
/// If a corresponding [`End`] event is not found, an error of type [`IllFormed`]
/// will be returned. In particularly, that error will be returned if you call
/// this method without consuming the corresponding [`Start`] event first.
///
/// If your reader created from a string slice or byte array slice, it is
/// better to use [`read_to_end()`] method, because it will not copy bytes
/// into intermediate buffer.
///
/// The provided `buf` buffer will be filled only by one event content at time.
/// Before reading of each event the buffer will be cleared. If you know an
/// appropriate size of each event, you can preallocate the buffer to reduce
/// number of reallocations.
///
/// The `end` parameter should contain name of the end element _in the reader
/// encoding_. It is good practice to always get that parameter using
/// [`BytesStart::to_end()`] method.
///
/// # Namespaces
///
/// While the `NsReader` does namespace resolution, namespaces does not
/// change the algorithm for comparing names. Although the names `a:name`
/// and `b:name` where both prefixes `a` and `b` resolves to the same namespace,
/// are semantically equivalent, `</b:name>` cannot close `<a:name>`, because
/// according to [the specification]
///
/// > The end of every element that begins with a **start-tag** MUST be marked
/// > by an **end-tag** containing a name that echoes the element's type as
/// > given in the **start-tag**
///
/// # Examples
///
/// This example shows, how you can skip XML content after you read the
/// start event.
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::{BytesStart, Event};
/// use quick_xml::name::{Namespace, ResolveResult};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <outer xmlns="namespace 1">
/// <inner xmlns="namespace 2">
/// <outer></outer>
/// </inner>
/// <inner>
/// <inner></inner>
/// <inner/>
/// <outer></outer>
/// <p:outer xmlns:p="ns"></p:outer>
/// <outer/>
/// </inner>
/// </outer>
/// "#);
/// reader.config_mut().trim_text(true);
/// let mut buf = Vec::new();
///
/// let ns = Namespace(b"namespace 1");
/// let start = BytesStart::from_content(r#"outer xmlns="namespace 1""#, 5);
/// let end = start.to_end().into_owned();
///
/// // First, we read a start event...
/// assert_eq!(
/// reader.read_resolved_event_into(&mut buf).unwrap(),
/// (ResolveResult::Bound(ns), Event::Start(start))
/// );
///
/// // ...then, we could skip all events to the corresponding end event.
/// // This call will correctly handle nested <outer> elements.
/// // Note, however, that this method does not handle namespaces.
/// reader.read_to_end_into(end.name(), &mut buf).unwrap();
///
/// // At the end we should get an Eof event, because we ate the whole XML
/// assert_eq!(
/// reader.read_resolved_event_into(&mut buf).unwrap(),
/// (ResolveResult::Unbound, Event::Eof)
/// );
/// ```
///
/// [`Start`]: Event::Start
/// [`End`]: Event::End
/// [`IllFormed`]: crate::errors::Error::IllFormed
/// [`read_to_end()`]: Self::read_to_end
/// [`BytesStart::to_end()`]: crate::events::BytesStart::to_end
/// [`expand_empty_elements`]: Config::expand_empty_elements
/// [the specification]: https://www.w3.org/TR/xml11/#dt-etag
#[inline]
pub fn read_to_end_into(&mut self, end: QName, buf: &mut Vec<u8>) -> Result<Span> {
// According to the https://www.w3.org/TR/xml11/#dt-etag, end name should
// match literally the start name. See `Config::check_end_names` documentation
self.reader.read_to_end_into(end, buf)
}
}
impl NsReader<BufReader<File>> {
/// Creates an XML reader from a file path.
pub fn from_file<P: AsRef<Path>>(path: P) -> Result<Self> {
Ok(Self::new(Reader::from_file(path)?))
}
}
impl<'i> NsReader<&'i [u8]> {
/// Creates an XML reader from a string slice.
#[inline]
#[allow(clippy::should_implement_trait)]
pub fn from_str(s: &'i str) -> Self {
Self::new(Reader::from_str(s))
}
/// Reads the next event, borrow its content from the input buffer.
///
/// This method manages namespaces but doesn't resolve them automatically.
/// You should call [`resolve_element()`] if you want to get a namespace.
///
/// You also can use [`read_resolved_event()`] instead if you want to resolve namespace
/// as soon as you get an event.
///
/// There is no asynchronous `read_event_async()` version of this function,
/// because it is not necessary -- the contents are already in memory and no IO
/// is needed, therefore there is no potential for blocking.
///
/// # Examples
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::Event;
/// use quick_xml::name::{Namespace, ResolveResult::*};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <x:tag1 xmlns:x="www.xxxx" xmlns:y="www.yyyy" att1 = "test">
/// <y:tag2><!--Test comment-->Test</y:tag2>
/// <y:tag2>Test 2</y:tag2>
/// </x:tag1>
/// "#);
/// reader.config_mut().trim_text(true);
///
/// let mut count = 0;
/// let mut txt = Vec::new();
/// loop {
/// match reader.read_event().unwrap() {
/// Event::Start(e) => {
/// count += 1;
/// let (ns, local) = reader.resolve_element(e.name());
/// match local.as_ref() {
/// b"tag1" => assert_eq!(ns, Bound(Namespace(b"www.xxxx"))),
/// b"tag2" => assert_eq!(ns, Bound(Namespace(b"www.yyyy"))),
/// _ => unreachable!(),
/// }
/// }
/// Event::Text(e) => {
/// txt.push(e.unescape().unwrap().into_owned())
/// }
/// Event::Eof => break,
/// _ => (),
/// }
/// }
/// assert_eq!(count, 3);
/// assert_eq!(txt, vec!["Test".to_string(), "Test 2".to_string()]);
/// ```
///
/// [`resolve_element()`]: Self::resolve_element
/// [`read_resolved_event()`]: Self::read_resolved_event
#[inline]
pub fn read_event(&mut self) -> Result<Event<'i>> {
self.read_event_impl(())
}
/// Reads the next event, borrow its content from the input buffer, and resolves
/// its namespace (if applicable).
///
/// Namespace is resolved only for [`Start`], [`Empty`] and [`End`] events.
/// For all other events the concept of namespace is not defined, so
/// a [`ResolveResult::Unbound`] is returned.
///
/// If you are not interested in namespaces, you can use [`read_event()`]
/// which will not automatically resolve namespaces for you.
///
/// There is no asynchronous `read_resolved_event_async()` version of this function,
/// because it is not necessary -- the contents are already in memory and no IO
/// is needed, therefore there is no potential for blocking.
///
/// # Examples
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::Event;
/// use quick_xml::name::{Namespace, QName, ResolveResult::*};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <x:tag1 xmlns:x="www.xxxx" xmlns:y="www.yyyy" att1 = "test">
/// <y:tag2><!--Test comment-->Test</y:tag2>
/// <y:tag2>Test 2</y:tag2>
/// </x:tag1>
/// "#);
/// reader.config_mut().trim_text(true);
///
/// let mut count = 0;
/// let mut txt = Vec::new();
/// loop {
/// match reader.read_resolved_event().unwrap() {
/// (Bound(Namespace(b"www.xxxx")), Event::Start(e)) => {
/// count += 1;
/// assert_eq!(e.local_name(), QName(b"tag1").into());
/// }
/// (Bound(Namespace(b"www.yyyy")), Event::Start(e)) => {
/// count += 1;
/// assert_eq!(e.local_name(), QName(b"tag2").into());
/// }
/// (_, Event::Start(_)) => unreachable!(),
///
/// (_, Event::Text(e)) => {
/// txt.push(e.unescape().unwrap().into_owned())
/// }
/// (_, Event::Eof) => break,
/// _ => (),
/// }
/// }
/// assert_eq!(count, 3);
/// assert_eq!(txt, vec!["Test".to_string(), "Test 2".to_string()]);
/// ```
///
/// [`Start`]: Event::Start
/// [`Empty`]: Event::Empty
/// [`End`]: Event::End
/// [`read_event()`]: Self::read_event
#[inline]
pub fn read_resolved_event(&mut self) -> Result<(ResolveResult, Event<'i>)> {
let event = self.read_event_impl(());
self.resolve_event(event)
}
/// Reads until end element is found. This function is supposed to be called
/// after you already read a [`Start`] event.
///
/// Returns a span that cover content between `>` of an opening tag and `<` of
/// a closing tag or an empty slice, if [`expand_empty_elements`] is set and
/// this method was called after reading expanded [`Start`] event.
///
/// Manages nested cases where parent and child elements have the _literally_
/// same name.
///
/// If a corresponding [`End`] event is not found, an error of type [`IllFormed`]
/// will be returned. In particularly, that error will be returned if you call
/// this method without consuming the corresponding [`Start`] event first.
///
/// The `end` parameter should contain name of the end element _in the reader
/// encoding_. It is good practice to always get that parameter using
/// [`BytesStart::to_end()`] method.
///
/// There is no asynchronous `read_to_end_async()` version of this function,
/// because it is not necessary -- the contents are already in memory and no IO
/// is needed, therefore there is no potential for blocking.
///
/// # Namespaces
///
/// While the `NsReader` does namespace resolution, namespaces does not
/// change the algorithm for comparing names. Although the names `a:name`
/// and `b:name` where both prefixes `a` and `b` resolves to the same namespace,
/// are semantically equivalent, `</b:name>` cannot close `<a:name>`, because
/// according to [the specification]
///
/// > The end of every element that begins with a **start-tag** MUST be marked
/// > by an **end-tag** containing a name that echoes the element's type as
/// > given in the **start-tag**
///
/// # Examples
///
/// This example shows, how you can skip XML content after you read the
/// start event.
///
/// ```
/// # use pretty_assertions::assert_eq;
/// use quick_xml::events::{BytesStart, Event};
/// use quick_xml::name::{Namespace, ResolveResult};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <outer xmlns="namespace 1">
/// <inner xmlns="namespace 2">
/// <outer></outer>
/// </inner>
/// <inner>
/// <inner></inner>
/// <inner/>
/// <outer></outer>
/// <p:outer xmlns:p="ns"></p:outer>
/// <outer/>
/// </inner>
/// </outer>
/// "#);
/// reader.config_mut().trim_text(true);
///
/// let ns = Namespace(b"namespace 1");
/// let start = BytesStart::from_content(r#"outer xmlns="namespace 1""#, 5);
/// let end = start.to_end().into_owned();
///
/// // First, we read a start event...
/// assert_eq!(
/// reader.read_resolved_event().unwrap(),
/// (ResolveResult::Bound(ns), Event::Start(start))
/// );
///
/// // ...then, we could skip all events to the corresponding end event.
/// // This call will correctly handle nested <outer> elements.
/// // Note, however, that this method does not handle namespaces.
/// reader.read_to_end(end.name()).unwrap();
///
/// // At the end we should get an Eof event, because we ate the whole XML
/// assert_eq!(
/// reader.read_resolved_event().unwrap(),
/// (ResolveResult::Unbound, Event::Eof)
/// );
/// ```
///
/// [`Start`]: Event::Start
/// [`End`]: Event::End
/// [`IllFormed`]: crate::errors::Error::IllFormed
/// [`BytesStart::to_end()`]: crate::events::BytesStart::to_end
/// [`expand_empty_elements`]: Config::expand_empty_elements
/// [the specification]: https://www.w3.org/TR/xml11/#dt-etag
#[inline]
pub fn read_to_end(&mut self, end: QName) -> Result<Span> {
// According to the https://www.w3.org/TR/xml11/#dt-etag, end name should
// match literally the start name. See `Config::check_end_names` documentation
self.reader.read_to_end(end)
}
/// Reads content between start and end tags, including any markup. This
/// function is supposed to be called after you already read a [`Start`] event.
///
/// Manages nested cases where parent and child elements have the _literally_
/// same name.
///
/// This method does not unescape read data, instead it returns content
/// "as is" of the XML document. This is because it has no idea what text
/// it reads, and if, for example, it contains CDATA section, attempt to
/// unescape it content will spoil data.
///
/// Any text will be decoded using the XML current [`decoder()`].
///
/// Actually, this method perform the following code:
///
/// ```ignore
/// let span = reader.read_to_end(end)?;
/// let text = reader.decoder().decode(&reader.inner_slice[span]);
/// ```
///
/// # Examples
///
/// This example shows, how you can read a HTML content from your XML document.
///
/// ```
/// # use pretty_assertions::assert_eq;
/// # use std::borrow::Cow;
/// use quick_xml::events::{BytesStart, Event};
/// use quick_xml::reader::NsReader;
///
/// let mut reader = NsReader::from_str(r#"
/// <html>
/// <title>This is a HTML text</title>
/// <p>Usual XML rules does not apply inside it
/// <p>For example, elements not needed to be "closed"
/// </html>
/// "#);
/// reader.config_mut().trim_text(true);
///
/// let start = BytesStart::new("html");
/// let end = start.to_end().into_owned();
///
/// // First, we read a start event...
/// assert_eq!(reader.read_event().unwrap(), Event::Start(start));
/// // ...and disable checking of end names because we expect HTML further...
/// reader.config_mut().check_end_names = false;
///
/// // ...then, we could read text content until close tag.
/// // This call will correctly handle nested <html> elements.
/// let text = reader.read_text(end.name()).unwrap();
/// assert_eq!(text, Cow::Borrowed(r#"
/// <title>This is a HTML text</title>
/// <p>Usual XML rules does not apply inside it
/// <p>For example, elements not needed to be "closed"
/// "#));
///
/// // Now we can enable checks again
/// reader.config_mut().check_end_names = true;
///
/// // At the end we should get an Eof event, because we ate the whole XML
/// assert_eq!(reader.read_event().unwrap(), Event::Eof);
/// ```
///
/// [`Start`]: Event::Start
/// [`decoder()`]: Reader::decoder()
#[inline]
pub fn read_text(&mut self, end: QName) -> Result<Cow<'i, str>> {
self.reader.read_text(end)
}
}
impl<R> Deref for NsReader<R> {
type Target = Reader<R>;
#[inline]
fn deref(&self) -> &Self::Target {
&self.reader
}
}