element.rs

   1//! Provides an `Element` type, which represents DOM nodes, and a builder to create them with.
   2
   3use std::io:: Write;
   4use std::collections::{btree_map, BTreeMap};
   5
   6use std::str;
   7use std::rc::Rc;
   8use std::borrow::Cow;
   9
  10use error::{Error, Result};
  11
  12use quick_xml::Reader as EventReader;
  13use quick_xml::Writer as EventWriter;
  14use quick_xml::events::{Event, BytesStart, BytesEnd, BytesText, BytesDecl};
  15
  16use std::io::BufRead;
  17
  18use std::str::FromStr;
  19
  20use std::slice;
  21
  22use convert::IntoAttributeValue;
  23use namespace_set::NamespaceSet;
  24
  25/// helper function to escape a `&[u8]` and replace all
  26/// xml special characters (<, >, &, ', ") with their corresponding
  27/// xml escaped value.
  28pub fn escape(raw: &[u8]) -> Cow<[u8]> {
  29    let mut escapes: Vec<(usize, &'static [u8])> = Vec::new();
  30    let mut bytes = raw.iter();
  31    fn to_escape(b: u8) -> bool {
  32        match b {
  33            b'<' | b'>' | b'\'' | b'&' | b'"' => true,
  34            _ => false,
  35        }
  36    }
  37
  38    let mut loc = 0;
  39    while let Some(i) = bytes.position(|&b| to_escape(b)) {
  40        loc += i;
  41        match raw[loc] {
  42            b'<' => escapes.push((loc, b"&lt;")),
  43            b'>' => escapes.push((loc, b"&gt;")),
  44            b'\'' => escapes.push((loc, b"&apos;")),
  45            b'&' => escapes.push((loc, b"&amp;")),
  46            b'"' => escapes.push((loc, b"&quot;")),
  47            _ => unreachable!("Only '<', '>','\', '&' and '\"' are escaped"),
  48        }
  49        loc += 1;
  50    }
  51
  52    if escapes.is_empty() {
  53        Cow::Borrowed(raw)
  54    } else {
  55        let len = raw.len();
  56        let mut v = Vec::with_capacity(len);
  57        let mut start = 0;
  58        for (i, r) in escapes {
  59            v.extend_from_slice(&raw[start..i]);
  60            v.extend_from_slice(r);
  61            start = i + 1;
  62        }
  63
  64        if start < len {
  65            v.extend_from_slice(&raw[start..]);
  66        }
  67        Cow::Owned(v)
  68    }
  69}
  70
  71/// A node in an element tree.
  72#[derive(Clone, Debug, PartialEq, Eq)]
  73pub enum Node {
  74    /// An `Element`.
  75    Element(Element),
  76    /// A text node.
  77    Text(String),
  78    /// A comment node.
  79    Comment(String),
  80}
  81
  82impl Node {
  83    /// Turns this into a reference to an `Element` if this is an element node.
  84    /// Else this returns `None`.
  85    ///
  86    /// # Examples
  87    ///
  88    /// ```rust
  89    /// use minidom::Node;
  90    ///
  91    /// let elm = Node::Element("<meow />".parse().unwrap());
  92    /// let txt = Node::Text("meow".to_owned());
  93    ///
  94    /// assert_eq!(elm.as_element().unwrap().name(), "meow");
  95    /// assert_eq!(txt.as_element(), None);
  96    /// ```
  97    pub fn as_element(&self) -> Option<&Element> {
  98        match *self {
  99            Node::Element(ref e) => Some(e),
 100            Node::Text(_) => None,
 101            Node::Comment(_) => None,
 102        }
 103    }
 104
 105    /// Turns this into a mutable reference of an `Element` if this is an element node.
 106    /// Else this returns `None`.
 107    ///
 108    /// # Examples
 109    ///
 110    /// ```rust
 111    /// use minidom::Node;
 112    ///
 113    /// let mut elm = Node::Element("<meow />".parse().unwrap());
 114    /// let mut txt = Node::Text("meow".to_owned());
 115    ///
 116    /// assert_eq!(elm.as_element_mut().unwrap().name(), "meow");
 117    /// assert_eq!(txt.as_element_mut(), None);
 118    /// ```
 119    pub fn as_element_mut(&mut self) -> Option<&mut Element> {
 120        match *self {
 121            Node::Element(ref mut e) => Some(e),
 122            Node::Text(_) => None,
 123            Node::Comment(_) => None,
 124        }
 125    }
 126
 127    /// Turns this into an `Element`, consuming self, if this is an element node.
 128    /// Else this returns `None`.
 129    ///
 130    /// # Examples
 131    ///
 132    /// ```rust
 133    /// use minidom::Node;
 134    ///
 135    /// let elm = Node::Element("<meow />".parse().unwrap());
 136    /// let txt = Node::Text("meow".to_owned());
 137    ///
 138    /// assert_eq!(elm.into_element().unwrap().name(), "meow");
 139    /// assert_eq!(txt.into_element(), None);
 140    /// ```
 141    pub fn into_element(self) -> Option<Element> {
 142        match self {
 143            Node::Element(e) => Some(e),
 144            Node::Text(_) => None,
 145            Node::Comment(_) => None,
 146        }
 147    }
 148
 149    /// Turns this into an `&str` if this is a text node.
 150    /// Else this returns `None`.
 151    ///
 152    /// # Examples
 153    ///
 154    /// ```rust
 155    /// use minidom::Node;
 156    ///
 157    /// let elm = Node::Element("<meow />".parse().unwrap());
 158    /// let txt = Node::Text("meow".to_owned());
 159    ///
 160    /// assert_eq!(elm.as_text(), None);
 161    /// assert_eq!(txt.as_text().unwrap(), "meow");
 162    /// ```
 163    pub fn as_text(&self) -> Option<&str> {
 164        match *self {
 165            Node::Element(_) => None,
 166            Node::Text(ref s) => Some(s),
 167            Node::Comment(_) => None,
 168        }
 169    }
 170
 171    /// Turns this into an `&mut String` if this is a text node.
 172    /// Else this returns `None`.
 173    ///
 174    /// # Examples
 175    ///
 176    /// ```rust
 177    /// use minidom::Node;
 178    ///
 179    /// let mut elm = Node::Element("<meow />".parse().unwrap());
 180    /// let mut txt = Node::Text("meow".to_owned());
 181    ///
 182    /// assert_eq!(elm.as_text_mut(), None);
 183    /// {
 184    ///     let text_mut = txt.as_text_mut().unwrap();
 185    ///     assert_eq!(text_mut, "meow");
 186    ///     text_mut.push_str("zies");
 187    ///     assert_eq!(text_mut, "meowzies");
 188    /// }
 189    /// assert_eq!(txt.as_text().unwrap(), "meowzies");
 190    /// ```
 191    pub fn as_text_mut(&mut self) -> Option<&mut String> {
 192        match *self {
 193            Node::Element(_) => None,
 194            Node::Text(ref mut s) => Some(s),
 195            Node::Comment(_) => None,
 196        }
 197    }
 198
 199    /// Turns this into an `String`, consuming self, if this is a text node.
 200    /// Else this returns `None`.
 201    ///
 202    /// # Examples
 203    ///
 204    /// ```rust
 205    /// use minidom::Node;
 206    ///
 207    /// let elm = Node::Element("<meow />".parse().unwrap());
 208    /// let txt = Node::Text("meow".to_owned());
 209    ///
 210    /// assert_eq!(elm.into_text(), None);
 211    /// assert_eq!(txt.into_text().unwrap(), "meow");
 212    /// ```
 213    pub fn into_text(self) -> Option<String> {
 214        match self {
 215            Node::Element(_) => None,
 216            Node::Text(s) => Some(s),
 217            Node::Comment(_) => None,
 218        }
 219    }
 220
 221    fn write_to_inner<W: Write>(&self, writer: &mut EventWriter<W>) -> Result<()>{
 222        match *self {
 223            Node::Element(ref elmt) => elmt.write_to_inner(writer)?,
 224            Node::Text(ref s) => {
 225                writer.write_event(Event::Text(BytesText::from_plain_str(s)))?;
 226                ()
 227            },
 228            Node::Comment(ref s) => {
 229                writer.write_event(Event::Comment(BytesText::from_plain_str(s)))?;
 230                ()
 231            },
 232        };
 233
 234        Ok(())
 235    }
 236}
 237
 238impl From<Element> for Node {
 239    fn from(elm: Element) -> Node {
 240        Node::Element(elm)
 241    }
 242}
 243
 244impl From<String> for Node {
 245    fn from(s: String) -> Node {
 246        Node::Text(s)
 247    }
 248}
 249
 250impl<'a> From<&'a str> for Node {
 251    fn from(s: &'a str) -> Node {
 252        Node::Text(s.to_owned())
 253    }
 254}
 255
 256impl From<ElementBuilder> for Node {
 257    fn from(builder: ElementBuilder) -> Node {
 258        Node::Element(builder.build())
 259    }
 260}
 261
 262#[derive(Clone, PartialEq, Eq, Debug)]
 263/// A struct representing a DOM Element.
 264pub struct Element {
 265    prefix: Option<String>,
 266    name: String,
 267    namespaces: Rc<NamespaceSet>,
 268    attributes: BTreeMap<String, String>,
 269    children: Vec<Node>,
 270}
 271
 272impl<'a> From<&'a Element> for String {
 273    fn from(elem: &'a Element) -> String {
 274        let mut writer = Vec::new();
 275        elem.write_to(&mut writer).unwrap();
 276        String::from_utf8(writer).unwrap()
 277    }
 278}
 279
 280impl FromStr for Element {
 281    type Err = Error;
 282
 283    fn from_str(s: &str) -> Result<Element> {
 284        let mut reader = EventReader::from_str(s);
 285        Element::from_reader(&mut reader)
 286    }
 287}
 288
 289impl Element {
 290    fn new<NS: Into<NamespaceSet>>(name: String, prefix: Option<String>, namespaces: NS, attributes: BTreeMap<String, String>, children: Vec<Node>) -> Element {
 291        Element {
 292            prefix, name,
 293            namespaces: Rc::new(namespaces.into()),
 294            attributes: attributes,
 295            children: children,
 296        }
 297    }
 298
 299    /// Return a builder for an `Element` with the given `name`.
 300    ///
 301    /// # Examples
 302    ///
 303    /// ```rust
 304    /// use minidom::Element;
 305    ///
 306    /// let elem = Element::builder("name")
 307    ///                    .ns("namespace")
 308    ///                    .attr("name", "value")
 309    ///                    .append("inner")
 310    ///                    .build();
 311    ///
 312    /// assert_eq!(elem.name(), "name");
 313    /// assert_eq!(elem.ns(), Some("namespace".to_owned()));
 314    /// assert_eq!(elem.attr("name"), Some("value"));
 315    /// assert_eq!(elem.attr("inexistent"), None);
 316    /// assert_eq!(elem.text(), "inner");
 317    /// ```
 318    pub fn builder<S: AsRef<str>>(name: S) -> ElementBuilder {
 319        let (prefix, name) = split_element_name(name).unwrap();
 320        ElementBuilder {
 321            root: Element::new(name, prefix, None, BTreeMap::new(), Vec::new()),
 322            namespaces: Default::default(),
 323        }
 324    }
 325
 326    /// Returns a bare minimum `Element` with this name.
 327    ///
 328    /// # Examples
 329    ///
 330    /// ```rust
 331    /// use minidom::Element;
 332    ///
 333    /// let bare = Element::bare("name");
 334    ///
 335    /// assert_eq!(bare.name(), "name");
 336    /// assert_eq!(bare.ns(), None);
 337    /// assert_eq!(bare.attr("name"), None);
 338    /// assert_eq!(bare.text(), "");
 339    /// ```
 340    pub fn bare<S: Into<String>>(name: S) -> Element {
 341        Element {
 342            prefix: None,
 343            name: name.into(),
 344            namespaces: Rc::new(NamespaceSet::default()),
 345            attributes: BTreeMap::new(),
 346            children: Vec::new(),
 347        }
 348    }
 349
 350    /// Returns a reference to the name of this element.
 351    pub fn name(&self) -> &str {
 352        &self.name
 353    }
 354
 355    /// Returns a reference to the prefix of this element.
 356    ///
 357    /// # Examples
 358    /// ```rust
 359    /// use minidom::Element;
 360    ///
 361    /// let elem = Element::builder("prefix:name")
 362    ///                    .build();
 363    ///
 364    /// assert_eq!(elem.name(), "name");
 365    /// assert_eq!(elem.prefix(), Some("prefix"));
 366    /// ```
 367    pub fn prefix(&self) -> Option<&str> {
 368        self.prefix.as_ref().map(String::as_ref)
 369    }
 370
 371    /// Returns a reference to the namespace of this element, if it has one, else `None`.
 372    pub fn ns(&self) -> Option<String> {
 373        self.namespaces.get(&self.prefix)
 374    }
 375
 376    /// Returns a reference to the value of the given attribute, if it exists, else `None`.
 377    pub fn attr(&self, name: &str) -> Option<&str> {
 378        if let Some(value) = self.attributes.get(name) {
 379            return Some(value)
 380        }
 381        None
 382    }
 383
 384    /// Returns an iterator over the attributes of this element.
 385    ///
 386    /// # Example
 387    ///
 388    /// ```rust
 389    /// use minidom::Element;
 390    ///
 391    /// let elm: Element = "<elem a=\"b\" />".parse().unwrap();
 392    ///
 393    /// let mut iter = elm.attrs();
 394    ///
 395    /// assert_eq!(iter.next().unwrap(), ("a", "b"));
 396    /// assert_eq!(iter.next(), None);
 397    /// ```
 398    pub fn attrs(&self) -> Attrs {
 399        Attrs {
 400            iter: self.attributes.iter(),
 401        }
 402    }
 403
 404    /// Returns an iterator over the attributes of this element, with the value being a mutable
 405    /// reference.
 406    pub fn attrs_mut(&mut self) -> AttrsMut {
 407        AttrsMut {
 408            iter: self.attributes.iter_mut(),
 409        }
 410    }
 411
 412    /// Modifies the value of an attribute.
 413    pub fn set_attr<S: Into<String>, V: IntoAttributeValue>(&mut self, name: S, val: V) {
 414        let name = name.into();
 415        let val = val.into_attribute_value();
 416
 417        if let Some(value) = self.attributes.get_mut(&name) {
 418            *value = val.expect("removing existing value via set_attr, this is not yet supported (TODO)"); // TODO
 419            return;
 420        }
 421
 422        if let Some(val) = val {
 423            self.attributes.insert(name, val);
 424        }
 425    }
 426
 427    /// Returns whether the element has the given name and namespace.
 428    ///
 429    /// # Examples
 430    ///
 431    /// ```rust
 432    /// use minidom::Element;
 433    ///
 434    /// let elem = Element::builder("name").ns("namespace").build();
 435    ///
 436    /// assert_eq!(elem.is("name", "namespace"), true);
 437    /// assert_eq!(elem.is("name", "wrong"), false);
 438    /// assert_eq!(elem.is("wrong", "namespace"), false);
 439    /// assert_eq!(elem.is("wrong", "wrong"), false);
 440    /// ```
 441    pub fn is<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> bool {
 442        self.name == name.as_ref() &&
 443            self.has_ns(namespace)
 444    }
 445
 446    /// Returns whether the element has the given namespace.
 447    ///
 448    /// # Examples
 449    ///
 450    /// ```rust
 451    /// use minidom::Element;
 452    ///
 453    /// let elem = Element::builder("name").ns("namespace").build();
 454    ///
 455    /// assert_eq!(elem.has_ns("namespace"), true);
 456    /// assert_eq!(elem.has_ns("wrong"), false);
 457    /// ```
 458    pub fn has_ns<NS: AsRef<str>>(&self, namespace: NS) -> bool {
 459        self.namespaces.has(&self.prefix, namespace)
 460    }
 461
 462    /// Parse a document from an `EventReader`.
 463    pub fn from_reader<R: BufRead>(reader: &mut EventReader<R>) -> Result<Element> {
 464        let mut buf = Vec::new();
 465
 466        let root: Element = loop {
 467            let e = reader.read_event(&mut buf)?;
 468            match e {
 469                Event::Empty(ref e) | Event::Start(ref e) => {
 470                    break build_element(reader, e)?;
 471                },
 472                Event::Eof => {
 473                    return Err(Error::EndOfDocument);
 474                },
 475                Event::Text { .. } |
 476                Event::End { .. } |
 477                Event::Comment { .. } |
 478                Event::CData { .. } |
 479                Event::Decl { .. } |
 480                Event::PI { .. } |
 481                Event::DocType { .. } => (), // TODO: may need more errors
 482            }
 483        };
 484
 485        let mut stack = vec![root];
 486
 487        loop {
 488            match reader.read_event(&mut buf)? {
 489                Event::Empty(ref e) => {
 490                    let elem = build_element(reader, e)?;
 491                    // Since there is no Event::End after, directly append it to the current node
 492                    stack.last_mut().unwrap().append_child(elem);
 493                },
 494                Event::Start(ref e) => {
 495                    let elem = build_element(reader, e)?;
 496                    stack.push(elem);
 497                },
 498                Event::End(ref e) => {
 499                    if stack.len() <= 1 {
 500                        break;
 501                    }
 502                    let elem = stack.pop().unwrap();
 503                    if let Some(to) = stack.last_mut() {
 504                        // TODO: check whether this is correct, we are comparing &[u8]s, not &strs
 505                        let elem_name = e.name();
 506                        let mut split_iter = elem_name.splitn(2, |u| *u == 0x3A);
 507                        let possible_prefix = split_iter.next().unwrap(); // Can't be empty.
 508                        match split_iter.next() {
 509                            Some(name) => {
 510                                match elem.prefix() {
 511                                    Some(prefix) => {
 512                                        if possible_prefix != prefix.as_bytes() {
 513                                            return Err(Error::InvalidElementClosed);
 514                                        }
 515                                    },
 516                                    None => {
 517                                        return Err(Error::InvalidElementClosed);
 518                                    },
 519                                }
 520                                if name != elem.name().as_bytes() {
 521                                    return Err(Error::InvalidElementClosed);
 522                                }
 523                            },
 524                            None => {
 525                                if elem.prefix().is_some() {
 526                                    return Err(Error::InvalidElementClosed);
 527                                }
 528                                if possible_prefix != elem.name().as_bytes() {
 529                                    return Err(Error::InvalidElementClosed);
 530                                }
 531                            },
 532                        }
 533                        to.append_child(elem);
 534                    }
 535                },
 536                Event::Text(s) => {
 537                    let text = s.unescape_and_decode(reader)?;
 538                    if text != "" {
 539                        let mut current_elem = stack.last_mut().unwrap();
 540                        current_elem.append_text_node(text);
 541                    }
 542                },
 543                Event::CData(s) => {
 544                    let text = reader.decode(&s).into_owned();
 545                    if text != "" {
 546                        let mut current_elem = stack.last_mut().unwrap();
 547                        current_elem.append_text_node(text);
 548                    }
 549                },
 550                Event::Eof => {
 551                    break;
 552                },
 553                Event::Comment(s) => {
 554                    let comment = reader.decode(&s).into_owned();
 555                    if comment != "" {
 556                        let current_elem = stack.last_mut().unwrap();
 557                        current_elem.append_comment_node(comment);
 558                    }
 559                },
 560                Event::Decl { .. } |
 561                Event::PI { .. } |
 562                Event::DocType { .. } => (),
 563            }
 564        }
 565        Ok(stack.pop().unwrap())
 566    }
 567
 568    /// Output a document to a `Writer`.
 569    pub fn write_to<W: Write>(&self, writer: &mut W) -> Result<()> {
 570        self.to_writer(&mut EventWriter::new(writer))
 571    }
 572
 573    /// Output the document to quick-xml `Writer`
 574    pub fn to_writer<W: Write>(&self, writer: &mut EventWriter<W>) -> Result<()> {
 575        writer.write_event(Event::Decl(BytesDecl::new(b"1.0", Some(b"utf-8"), None)))?;
 576        self.write_to_inner(writer)
 577    }
 578
 579    /// Like `write_to()` but without the `<?xml?>` prelude
 580    pub fn write_to_inner<W: Write>(&self, writer: &mut EventWriter<W>) -> Result<()> {
 581        let name = match self.prefix {
 582            None => Cow::Borrowed(&self.name),
 583            Some(ref prefix) => Cow::Owned(format!("{}:{}", prefix, self.name)),
 584        };
 585
 586        let mut start = BytesStart::borrowed(name.as_bytes(), name.len());
 587        for (prefix, ns) in self.namespaces.declared_ns() {
 588            match *prefix {
 589                None => start.push_attribute(("xmlns", ns.as_ref())),
 590                Some(ref prefix) => {
 591                    let key = format!("xmlns:{}", prefix);
 592                    start.push_attribute((key.as_bytes(), ns.as_bytes()))
 593                },
 594            }
 595        }
 596        for (key, value) in &self.attributes {
 597            start.push_attribute((key.as_bytes(), escape(value.as_bytes()).as_ref()));
 598        }
 599
 600        if self.children.is_empty() {
 601            writer.write_event(Event::Empty(start))?;
 602            return Ok(())
 603        }
 604
 605        writer.write_event(Event::Start(start))?;
 606
 607        for child in &self.children {
 608            child.write_to_inner(writer)?;
 609        }
 610
 611        writer.write_event(Event::End(BytesEnd::borrowed(name.as_bytes())))?;
 612        Ok(())
 613    }
 614
 615    /// Returns an iterator over references to every child node of this element.
 616    ///
 617    /// # Examples
 618    ///
 619    /// ```rust
 620    /// use minidom::Element;
 621    ///
 622    /// let elem: Element = "<root>a<c1 />b<c2 />c</root>".parse().unwrap();
 623    ///
 624    /// let mut iter = elem.nodes();
 625    ///
 626    /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "a");
 627    /// assert_eq!(iter.next().unwrap().as_element().unwrap().name(), "c1");
 628    /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "b");
 629    /// assert_eq!(iter.next().unwrap().as_element().unwrap().name(), "c2");
 630    /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "c");
 631    /// assert_eq!(iter.next(), None);
 632    /// ```
 633    #[inline] pub fn nodes(&self) -> Nodes {
 634        self.children.iter()
 635    }
 636
 637    /// Returns an iterator over mutable references to every child node of this element.
 638    #[inline] pub fn nodes_mut(&mut self) -> NodesMut {
 639        self.children.iter_mut()
 640    }
 641
 642    /// Returns an iterator over references to every child element of this element.
 643    ///
 644    /// # Examples
 645    ///
 646    /// ```rust
 647    /// use minidom::Element;
 648    ///
 649    /// let elem: Element = "<root>hello<child1 />this<child2 />is<child3 />ignored</root>".parse().unwrap();
 650    ///
 651    /// let mut iter = elem.children();
 652    /// assert_eq!(iter.next().unwrap().name(), "child1");
 653    /// assert_eq!(iter.next().unwrap().name(), "child2");
 654    /// assert_eq!(iter.next().unwrap().name(), "child3");
 655    /// assert_eq!(iter.next(), None);
 656    /// ```
 657    #[inline] pub fn children(&self) -> Children {
 658        Children {
 659            iter: self.children.iter(),
 660        }
 661    }
 662
 663    /// Returns an iterator over mutable references to every child element of this element.
 664    #[inline] pub fn children_mut(&mut self) -> ChildrenMut {
 665        ChildrenMut {
 666            iter: self.children.iter_mut(),
 667        }
 668    }
 669
 670    /// Returns an iterator over references to every text node of this element.
 671    ///
 672    /// # Examples
 673    ///
 674    /// ```rust
 675    /// use minidom::Element;
 676    ///
 677    /// let elem: Element = "<root>hello<c /> world!</root>".parse().unwrap();
 678    ///
 679    /// let mut iter = elem.texts();
 680    /// assert_eq!(iter.next().unwrap(), "hello");
 681    /// assert_eq!(iter.next().unwrap(), " world!");
 682    /// assert_eq!(iter.next(), None);
 683    /// ```
 684    #[inline] pub fn texts(&self) -> Texts {
 685        Texts {
 686            iter: self.children.iter(),
 687        }
 688    }
 689
 690    /// Returns an iterator over mutable references to every text node of this element.
 691    #[inline] pub fn texts_mut(&mut self) -> TextsMut {
 692        TextsMut {
 693            iter: self.children.iter_mut(),
 694        }
 695    }
 696
 697    /// Appends a child node to the `Element`, returning the appended node.
 698    ///
 699    /// # Examples
 700    ///
 701    /// ```rust
 702    /// use minidom::Element;
 703    ///
 704    /// let mut elem = Element::bare("root");
 705    ///
 706    /// assert_eq!(elem.children().count(), 0);
 707    ///
 708    /// elem.append_child(Element::bare("child"));
 709    ///
 710    /// {
 711    ///     let mut iter = elem.children();
 712    ///     assert_eq!(iter.next().unwrap().name(), "child");
 713    ///     assert_eq!(iter.next(), None);
 714    /// }
 715    ///
 716    /// let child = elem.append_child(Element::bare("new"));
 717    ///
 718    /// assert_eq!(child.name(), "new");
 719    /// ```
 720    pub fn append_child(&mut self, child: Element) -> &mut Element {
 721        child.namespaces.set_parent(Rc::clone(&self.namespaces));
 722
 723        self.children.push(Node::Element(child));
 724        if let Node::Element(ref mut cld) = *self.children.last_mut().unwrap() {
 725            cld
 726        } else {
 727            unreachable!()
 728        }
 729    }
 730
 731    /// Appends a text node to an `Element`.
 732    ///
 733    /// # Examples
 734    ///
 735    /// ```rust
 736    /// use minidom::Element;
 737    ///
 738    /// let mut elem = Element::bare("node");
 739    ///
 740    /// assert_eq!(elem.text(), "");
 741    ///
 742    /// elem.append_text_node("text");
 743    ///
 744    /// assert_eq!(elem.text(), "text");
 745    /// ```
 746    pub fn append_text_node<S: Into<String>>(&mut self, child: S) {
 747        self.children.push(Node::Text(child.into()));
 748    }
 749
 750    /// Appends a comment node to an `Element`.
 751    ///
 752    /// # Examples
 753    ///
 754    /// ```rust
 755    /// use minidom::Element;
 756    ///
 757    /// let mut elem = Element::bare("node");
 758    ///
 759    /// elem.append_comment_node("comment");
 760    /// ```
 761    pub fn append_comment_node<S: Into<String>>(&mut self, child: S) {
 762        self.children.push(Node::Comment(child.into()));
 763    }
 764
 765    /// Appends a node to an `Element`.
 766    ///
 767    /// # Examples
 768    ///
 769    /// ```rust
 770    /// use minidom::{Element, Node};
 771    ///
 772    /// let mut elem = Element::bare("node");
 773    ///
 774    /// elem.append_node(Node::Text("hello".to_owned()));
 775    ///
 776    /// assert_eq!(elem.text(), "hello");
 777    /// ```
 778    pub fn append_node(&mut self, node: Node) {
 779        self.children.push(node);
 780    }
 781
 782    /// Returns the concatenation of all text nodes in the `Element`.
 783    ///
 784    /// # Examples
 785    ///
 786    /// ```rust
 787    /// use minidom::Element;
 788    ///
 789    /// let elem: Element = "<node>hello,<split /> world!</node>".parse().unwrap();
 790    ///
 791    /// assert_eq!(elem.text(), "hello, world!");
 792    /// ```
 793    pub fn text(&self) -> String {
 794        self.texts().fold(String::new(), |ret, new| ret + new)
 795    }
 796
 797    /// Returns a reference to the first child element with the specific name and namespace, if it
 798    /// exists in the direct descendants of this `Element`, else returns `None`.
 799    ///
 800    /// # Examples
 801    ///
 802    /// ```rust
 803    /// use minidom::Element;
 804    ///
 805    /// let elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
 806    ///
 807    /// assert!(elem.get_child("a", "ns").unwrap().is("a", "ns"));
 808    /// assert!(elem.get_child("a", "other_ns").unwrap().is("a", "other_ns"));
 809    /// assert!(elem.get_child("b", "ns").unwrap().is("b", "ns"));
 810    /// assert_eq!(elem.get_child("c", "ns"), None);
 811    /// assert_eq!(elem.get_child("b", "other_ns"), None);
 812    /// assert_eq!(elem.get_child("a", "inexistent_ns"), None);
 813    /// ```
 814    pub fn get_child<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> Option<&Element> {
 815        for fork in &self.children {
 816            if let Node::Element(ref e) = *fork {
 817                if e.is(name.as_ref(), namespace.as_ref()) {
 818                    return Some(e);
 819                }
 820            }
 821        }
 822        None
 823    }
 824
 825    /// Returns a mutable reference to the first child element with the specific name and namespace,
 826    /// if it exists in the direct descendants of this `Element`, else returns `None`.
 827    pub fn get_child_mut<N: AsRef<str>, NS: AsRef<str>>(&mut self, name: N, namespace: NS) -> Option<&mut Element> {
 828        for fork in &mut self.children {
 829            if let Node::Element(ref mut e) = *fork {
 830                if e.is(name.as_ref(), namespace.as_ref()) {
 831                    return Some(e);
 832                }
 833            }
 834        }
 835        None
 836    }
 837
 838    /// Returns whether a specific child with this name and namespace exists in the direct
 839    /// descendants of the `Element`.
 840    ///
 841    /// # Examples
 842    ///
 843    /// ```rust
 844    /// use minidom::Element;
 845    ///
 846    /// let elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
 847    ///
 848    /// assert_eq!(elem.has_child("a", "other_ns"), true);
 849    /// assert_eq!(elem.has_child("a", "ns"), true);
 850    /// assert_eq!(elem.has_child("a", "inexistent_ns"), false);
 851    /// assert_eq!(elem.has_child("b", "ns"), true);
 852    /// assert_eq!(elem.has_child("b", "other_ns"), false);
 853    /// assert_eq!(elem.has_child("b", "inexistent_ns"), false);
 854    /// ```
 855    pub fn has_child<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> bool {
 856        self.get_child(name, namespace).is_some()
 857    }
 858
 859    /// Removes the first child with this name and namespace, if it exists, and returns an
 860    /// `Option<Element>` containing this child if it succeeds.
 861    /// Returns `None` if no child matches this name and namespace.
 862    ///
 863    /// # Examples
 864    ///
 865    /// ```rust
 866    /// use minidom::Element;
 867    ///
 868    /// let mut elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
 869    ///
 870    /// assert!(elem.remove_child("a", "ns").unwrap().is("a", "ns"));
 871    /// assert!(elem.remove_child("a", "ns").is_none());
 872    /// assert!(elem.remove_child("inexistent", "inexistent").is_none());
 873    /// ```
 874    pub fn remove_child<N: AsRef<str>, NS: AsRef<str>>(&mut self, name: N, namespace: NS) -> Option<Element> {
 875        let name = name.as_ref();
 876        let namespace = namespace.as_ref();
 877        let idx = self.children.iter().position(|x| {
 878            if let Node::Element(ref elm) = x {
 879                elm.is(name, namespace)
 880            } else {
 881                false
 882            }
 883        })?;
 884        self.children.remove(idx).into_element()
 885    }
 886}
 887
 888fn split_element_name<S: AsRef<str>>(s: S) -> Result<(Option<String>, String)> {
 889    let name_parts = s.as_ref().split(':').collect::<Vec<&str>>();
 890    match name_parts.len() {
 891        2 => Ok((Some(name_parts[0].to_owned()), name_parts[1].to_owned())),
 892        1 => Ok((None, name_parts[0].to_owned())),
 893        _ => Err(Error::InvalidElement),
 894    }
 895}
 896
 897fn build_element<R: BufRead>(reader: &EventReader<R>, event: &BytesStart) -> Result<Element> {
 898    let mut namespaces = BTreeMap::new();
 899    let attributes = event.attributes()
 900        .map(|o| {
 901            let o = o?;
 902            let key = str::from_utf8(o.key)?.to_owned();
 903            let value = o.unescape_and_decode_value(reader)?;
 904            Ok((key, value))
 905        })
 906        .filter(|o| {
 907            match *o {
 908                Ok((ref key, ref value)) if key == "xmlns" => {
 909                    namespaces.insert(None, value.to_owned());
 910                    false
 911                },
 912                Ok((ref key, ref value)) if key.starts_with("xmlns:") => {
 913                    namespaces.insert(Some(key[6..].to_owned()), value.to_owned());
 914                    false
 915                },
 916                _ => true,
 917            }
 918        })
 919        .collect::<Result<BTreeMap<String, String>>>()?;
 920
 921    let (prefix, name) = split_element_name(str::from_utf8(event.name())?)?;
 922    let element = Element::new(name, prefix, namespaces, attributes, Vec::new());
 923    Ok(element)
 924}
 925
 926/// An iterator over references to child elements of an `Element`.
 927pub struct Children<'a> {
 928    iter: slice::Iter<'a, Node>,
 929}
 930
 931impl<'a> Iterator for Children<'a> {
 932    type Item = &'a Element;
 933
 934    fn next(&mut self) -> Option<&'a Element> {
 935        for item in &mut self.iter {
 936            if let Node::Element(ref child) = *item {
 937                return Some(child);
 938            }
 939        }
 940        None
 941    }
 942}
 943
 944/// An iterator over mutable references to child elements of an `Element`.
 945pub struct ChildrenMut<'a> {
 946    iter: slice::IterMut<'a, Node>,
 947}
 948
 949impl<'a> Iterator for ChildrenMut<'a> {
 950    type Item = &'a mut Element;
 951
 952    fn next(&mut self) -> Option<&'a mut Element> {
 953        for item in &mut self.iter {
 954            if let Node::Element(ref mut child) = *item {
 955                return Some(child);
 956            }
 957        }
 958        None
 959    }
 960}
 961
 962/// An iterator over references to child text nodes of an `Element`.
 963pub struct Texts<'a> {
 964    iter: slice::Iter<'a, Node>,
 965}
 966
 967impl<'a> Iterator for Texts<'a> {
 968    type Item = &'a str;
 969
 970    fn next(&mut self) -> Option<&'a str> {
 971        for item in &mut self.iter {
 972            if let Node::Text(ref child) = *item {
 973                return Some(child);
 974            }
 975        }
 976        None
 977    }
 978}
 979
 980/// An iterator over mutable references to child text nodes of an `Element`.
 981pub struct TextsMut<'a> {
 982    iter: slice::IterMut<'a, Node>,
 983}
 984
 985impl<'a> Iterator for TextsMut<'a> {
 986    type Item = &'a mut String;
 987
 988    fn next(&mut self) -> Option<&'a mut String> {
 989        for item in &mut self.iter {
 990            if let Node::Text(ref mut child) = *item {
 991                return Some(child);
 992            }
 993        }
 994        None
 995    }
 996}
 997
 998/// An iterator over references to all child nodes of an `Element`.
 999pub type Nodes<'a> = slice::Iter<'a, Node>;
1000
1001/// An iterator over mutable references to all child nodes of an `Element`.
1002pub type NodesMut<'a> = slice::IterMut<'a, Node>;
1003
1004/// An iterator over the attributes of an `Element`.
1005pub struct Attrs<'a> {
1006    iter: btree_map::Iter<'a, String, String>,
1007}
1008
1009impl<'a> Iterator for Attrs<'a> {
1010    type Item = (&'a str, &'a str);
1011
1012    fn next(&mut self) -> Option<Self::Item> {
1013        self.iter.next().map(|(x, y)| (x.as_ref(), y.as_ref()))
1014    }
1015}
1016
1017/// An iterator over the attributes of an `Element`, with the values mutable.
1018pub struct AttrsMut<'a> {
1019    iter: btree_map::IterMut<'a, String, String>,
1020}
1021
1022impl<'a> Iterator for AttrsMut<'a> {
1023    type Item = (&'a str, &'a mut String);
1024
1025    fn next(&mut self) -> Option<Self::Item> {
1026        self.iter.next().map(|(x, y)| (x.as_ref(), y))
1027    }
1028}
1029
1030/// A builder for `Element`s.
1031pub struct ElementBuilder {
1032    root: Element,
1033    namespaces: BTreeMap<Option<String>, String>,
1034}
1035
1036impl ElementBuilder {
1037    /// Sets the namespace.
1038    pub fn ns<S: Into<String>>(mut self, namespace: S) -> ElementBuilder {
1039        self.namespaces
1040            .insert(self.root.prefix.clone(), namespace.into());
1041        self
1042    }
1043
1044    /// Sets an attribute.
1045    pub fn attr<S: Into<String>, V: IntoAttributeValue>(mut self, name: S, value: V) -> ElementBuilder {
1046        self.root.set_attr(name, value);
1047        self
1048    }
1049
1050    /// Appends anything implementing `Into<Node>` into the tree.
1051    pub fn append<T: Into<Node>>(mut self, node: T) -> ElementBuilder {
1052        self.root.append_node(node.into());
1053        self
1054    }
1055
1056    /// Appends an iterator of things implementing `Into<Node>` into the tree.
1057    pub fn append_all<T: Into<Node>, I: IntoIterator<Item = T>>(mut self, iter: I) -> ElementBuilder {
1058        for node in iter {
1059            self.root.append_node(node.into());
1060        }
1061        self
1062    }
1063
1064    /// Builds the `Element`.
1065    pub fn build(self) -> Element {
1066        let mut element = self.root;
1067        // Set namespaces
1068        element.namespaces = Rc::new(NamespaceSet::from(self.namespaces));
1069        // Propagate namespaces
1070        for node in &element.children {
1071            if let Node::Element(ref e) = *node {
1072                e.namespaces.set_parent(Rc::clone(&element.namespaces));
1073            }
1074        }
1075        element
1076    }
1077}
1078
1079#[cfg(test)]
1080mod tests {
1081    use super::*;
1082
1083    #[test]
1084    fn test_element_new() {
1085        use std::iter::FromIterator;
1086
1087        let elem = Element::new( "name".to_owned()
1088                               , None
1089                               , Some("namespace".to_owned())
1090                               , BTreeMap::from_iter(vec![ ("name".to_string(), "value".to_string()) ].into_iter() )
1091                               , Vec::new() );
1092
1093        assert_eq!(elem.name(), "name");
1094        assert_eq!(elem.ns(), Some("namespace".to_owned()));
1095        assert_eq!(elem.attr("name"), Some("value"));
1096        assert_eq!(elem.attr("inexistent"), None);
1097    }
1098
1099    #[test]
1100    fn test_from_reader_simple() {
1101        let xml = "<foo></foo>";
1102        let mut reader = EventReader::from_str(xml);
1103        let elem = Element::from_reader(&mut reader);
1104
1105        let elem2 = Element::builder("foo").build();
1106
1107        assert_eq!(elem.unwrap(), elem2);
1108    }
1109
1110    #[test]
1111    fn test_from_reader_nested() {
1112        let xml = "<foo><bar baz='qxx' /></foo>";
1113        let mut reader = EventReader::from_str(xml);
1114        let elem = Element::from_reader(&mut reader);
1115
1116        let nested = Element::builder("bar")
1117                             .attr("baz", "qxx")
1118                             .build();
1119        let elem2 = Element::builder("foo")
1120                            .append(nested)
1121                            .build();
1122
1123        assert_eq!(elem.unwrap(), elem2);
1124    }
1125
1126    #[test]
1127    fn test_from_reader_with_prefix() {
1128        let xml = "<foo><prefix:bar baz='qxx' /></foo>";
1129        let mut reader = EventReader::from_str(xml);
1130        let elem = Element::from_reader(&mut reader);
1131
1132        let nested = Element::builder("prefix:bar")
1133                             .attr("baz", "qxx")
1134                             .build();
1135        let elem2 = Element::builder("foo")
1136                            .append(nested)
1137                            .build();
1138
1139        assert_eq!(elem.unwrap(), elem2);
1140    }
1141
1142    #[test]
1143    fn parses_spectest_xml() { // From: https://gitlab.com/lumi/minidom-rs/issues/8
1144        let xml = r#"
1145            <rng:grammar xmlns:rng="http://relaxng.org/ns/structure/1.0">
1146                <rng:name xmlns:rng="http://relaxng.org/ns/structure/1.0"></rng:name>
1147            </rng:grammar>
1148        "#;
1149        let mut reader = EventReader::from_str(xml);
1150        let _ = Element::from_reader(&mut reader).unwrap();
1151    }
1152
1153    #[test]
1154    fn does_not_unescape_cdata() {
1155        let xml = "<test><![CDATA[&apos;&gt;blah<blah>]]></test>";
1156        let mut reader = EventReader::from_str(xml);
1157        let elem = Element::from_reader(&mut reader).unwrap();
1158        assert_eq!(elem.text(), "&apos;&gt;blah<blah>");
1159    }
1160}