element.rs

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