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, ErrorKind, Result};
11
12use quick_xml::reader::Reader as EventReader;
13use quick_xml::events::{Event, BytesStart};
14
15use std::io::BufRead;
16
17use std::str::FromStr;
18
19use std::slice;
20
21use convert::{IntoElements, IntoAttributeValue, ElementEmitter};
22use namespace_set::NamespaceSet;
23
24/// Escape XML text
25pub fn write_escaped<W: Write>(writer: &mut W, input: &str) -> Result<()> {
26 for c in input.chars() {
27 match c {
28 '&' => write!(writer, "&")?,
29 '<' => write!(writer, "<")?,
30 '>' => write!(writer, ">")?,
31 '\'' => write!(writer, "'")?,
32 '"' => write!(writer, """)?,
33 _ => write!(writer, "{}", c)?,
34 }
35 }
36
37 Ok(())
38}
39
40/// A node in an element tree.
41#[derive(Clone, Debug, PartialEq, Eq)]
42pub enum Node {
43 /// An `Element`.
44 Element(Element),
45 /// A text node.
46 Text(String),
47}
48
49impl Node {
50 /// Turns this into an `Element` if possible, else returns None.
51 ///
52 /// # Examples
53 ///
54 /// ```rust
55 /// use minidom::Node;
56 ///
57 /// let elm = Node::Element("<meow />".parse().unwrap());
58 /// let txt = Node::Text("meow".to_owned());
59 ///
60 /// assert_eq!(elm.as_element().unwrap().name(), "meow");
61 /// assert_eq!(txt.as_element(), None);
62 /// ```
63 pub fn as_element(&self) -> Option<&Element> {
64 match *self {
65 Node::Element(ref e) => Some(e),
66 Node::Text(_) => None,
67 }
68 }
69
70 /// Turns this into a `String` if possible, else returns None.
71 ///
72 /// # Examples
73 ///
74 /// ```rust
75 /// use minidom::Node;
76 ///
77 /// let elm = Node::Element("<meow />".parse().unwrap());
78 /// let txt = Node::Text("meow".to_owned());
79 ///
80 /// assert_eq!(elm.as_text(), None);
81 /// assert_eq!(txt.as_text().unwrap(), "meow");
82 /// ```
83 pub fn as_text(&self) -> Option<&str> {
84 match *self {
85 Node::Element(_) => None,
86 Node::Text(ref s) => Some(s),
87 }
88 }
89
90 fn write_to_inner<W: Write>(&self, writer: &mut W) -> Result<()>{
91 match *self {
92 Node::Element(ref elmt) => elmt.write_to_inner(writer)?,
93 Node::Text(ref s) => write_escaped(writer, s)?,
94 }
95
96 Ok(())
97 }
98}
99
100#[derive(Clone, PartialEq, Eq, Debug)]
101/// A struct representing a DOM Element.
102pub struct Element {
103 prefix: Option<String>,
104 name: String,
105 namespaces: Rc<NamespaceSet>,
106 attributes: BTreeMap<String, String>,
107 children: Vec<Node>,
108}
109
110impl<'a> From<&'a Element> for String {
111 fn from(elem: &'a Element) -> String {
112 let mut writer = Vec::new();
113 elem.write_to(&mut writer).unwrap();
114 String::from_utf8(writer).unwrap()
115 }
116}
117
118
119impl FromStr for Element {
120 type Err = Error;
121
122 fn from_str(s: &str) -> Result<Element> {
123 let mut reader = EventReader::from_str(s);
124 Element::from_reader(&mut reader)
125 }
126}
127
128impl Element {
129 fn new<NS: Into<NamespaceSet>>(name: String, prefix: Option<String>, namespaces: NS, attributes: BTreeMap<String, String>, children: Vec<Node>) -> Element {
130 Element {
131 prefix, name,
132 namespaces: Rc::new(namespaces.into()),
133 attributes: attributes,
134 children: children,
135 }
136 }
137
138 /// Return a builder for an `Element` with the given `name`.
139 ///
140 /// # Examples
141 ///
142 /// ```rust
143 /// use minidom::Element;
144 ///
145 /// let elem = Element::builder("name")
146 /// .ns("namespace")
147 /// .attr("name", "value")
148 /// .append("inner")
149 /// .build();
150 ///
151 /// assert_eq!(elem.name(), "name");
152 /// assert_eq!(elem.ns(), Some("namespace".to_owned()));
153 /// assert_eq!(elem.attr("name"), Some("value"));
154 /// assert_eq!(elem.attr("inexistent"), None);
155 /// assert_eq!(elem.text(), "inner");
156 /// ```
157 pub fn builder<S: AsRef<str>>(name: S) -> ElementBuilder {
158 let (prefix, name) = split_element_name(name).unwrap();
159 ElementBuilder {
160 root: Element::new(name, prefix, None, BTreeMap::new(), Vec::new()),
161 namespaces: Default::default(),
162 }
163 }
164
165 /// Returns a bare minimum `Element` with this name.
166 ///
167 /// # Examples
168 ///
169 /// ```rust
170 /// use minidom::Element;
171 ///
172 /// let bare = Element::bare("name");
173 ///
174 /// assert_eq!(bare.name(), "name");
175 /// assert_eq!(bare.ns(), None);
176 /// assert_eq!(bare.attr("name"), None);
177 /// assert_eq!(bare.text(), "");
178 /// ```
179 pub fn bare<S: Into<String>>(name: S) -> Element {
180 Element {
181 prefix: None,
182 name: name.into(),
183 namespaces: Rc::new(NamespaceSet::default()),
184 attributes: BTreeMap::new(),
185 children: Vec::new(),
186 }
187 }
188
189 /// Returns a reference to the name of this element.
190 pub fn name(&self) -> &str {
191 &self.name
192 }
193
194 /// Returns a reference to the prefix of this element.
195 ///
196 /// # Examples
197 /// ```rust
198 /// use minidom::Element;
199 ///
200 /// let elem = Element::builder("prefix:name")
201 /// .build();
202 ///
203 /// assert_eq!(elem.name(), "name");
204 /// assert_eq!(elem.prefix(), Some("prefix"));
205 /// ```
206 pub fn prefix(&self) -> Option<&str> {
207 self.prefix.as_ref().map(String::as_ref)
208 }
209
210 /// Returns a reference to the namespace of this element, if it has one, else `None`.
211 pub fn ns(&self) -> Option<String> {
212 self.namespaces.get(&self.prefix)
213 }
214
215 /// Returns a reference to the value of the given attribute, if it exists, else `None`.
216 pub fn attr(&self, name: &str) -> Option<&str> {
217 if let Some(value) = self.attributes.get(name) {
218 return Some(value)
219 }
220 None
221 }
222
223 /// Returns an iterator over the attributes of this element.
224 ///
225 /// # Example
226 ///
227 /// ```rust
228 /// use minidom::Element;
229 ///
230 /// let elm: Element = "<elem a=\"b\" />".parse().unwrap();
231 ///
232 /// let mut iter = elm.attrs();
233 ///
234 /// assert_eq!(iter.next().unwrap(), ("a", "b"));
235 /// assert_eq!(iter.next(), None);
236 /// ```
237 pub fn attrs(&self) -> Attrs {
238 Attrs {
239 iter: self.attributes.iter(),
240 }
241 }
242
243 /// Returns an iterator over the attributes of this element, with the value being a mutable
244 /// reference.
245 pub fn attrs_mut(&mut self) -> AttrsMut {
246 AttrsMut {
247 iter: self.attributes.iter_mut(),
248 }
249 }
250
251 /// Modifies the value of an attribute.
252 pub fn set_attr<S: Into<String>, V: IntoAttributeValue>(&mut self, name: S, val: V) {
253 let name = name.into();
254 let val = val.into_attribute_value();
255
256 if let Some(value) = self.attributes.get_mut(&name) {
257 *value = val.expect("removing existing value via set_attr, this is not yet supported (TODO)"); // TODO
258 return;
259 }
260
261 if let Some(val) = val {
262 self.attributes.insert(name, val);
263 }
264 }
265
266 /// Returns whether the element has the given name and namespace.
267 ///
268 /// # Examples
269 ///
270 /// ```rust
271 /// use minidom::Element;
272 ///
273 /// let elem = Element::builder("name").ns("namespace").build();
274 ///
275 /// assert_eq!(elem.is("name", "namespace"), true);
276 /// assert_eq!(elem.is("name", "wrong"), false);
277 /// assert_eq!(elem.is("wrong", "namespace"), false);
278 /// assert_eq!(elem.is("wrong", "wrong"), false);
279 /// ```
280 pub fn is<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> bool {
281 self.name == name.as_ref() &&
282 self.has_ns(namespace)
283 }
284
285 /// Returns whether the element has the given namespace.
286 ///
287 /// # Examples
288 ///
289 /// ```rust
290 /// use minidom::Element;
291 ///
292 /// let elem = Element::builder("name").ns("namespace").build();
293 ///
294 /// assert_eq!(elem.has_ns("namespace"), true);
295 /// assert_eq!(elem.has_ns("wrong"), false);
296 /// ```
297 pub fn has_ns<NS: AsRef<str>>(&self, namespace: NS) -> bool {
298 self.namespaces.has(&self.prefix, namespace)
299 }
300
301 /// Parse a document from an `EventReader`.
302 pub fn from_reader<R: BufRead>(reader: &mut EventReader<R>) -> Result<Element> {
303 let mut buf = Vec::new();
304
305 let root: Element = loop {
306 let e = reader.read_event(&mut buf)?;
307 match e {
308 Event::Empty(ref e) | Event::Start(ref e) => {
309 break build_element(reader, e)?;
310 },
311 Event::Eof => {
312 bail!(ErrorKind::EndOfDocument);
313 },
314 Event::Text { .. } |
315 Event::End { .. } |
316 Event::Comment { .. } |
317 Event::CData { .. } |
318 Event::Decl { .. } |
319 Event::PI { .. } |
320 Event::DocType { .. } => (), // TODO: may need more errors
321 }
322 };
323
324 let mut stack = vec![root];
325
326 loop {
327 match reader.read_event(&mut buf)? {
328 Event::Empty(ref e) => {
329 let elem = build_element(reader, e)?;
330 // Since there is no Event::End after, directly append it to the current node
331 stack.last_mut().unwrap().append_child(elem);
332 },
333 Event::Start(ref e) => {
334 let elem = build_element(reader, e)?;
335 stack.push(elem);
336 },
337 Event::End(ref e) => {
338 if stack.len() <= 1 {
339 break;
340 }
341 let elem = stack.pop().unwrap();
342 if let Some(to) = stack.last_mut() {
343 let name = match elem.prefix() {
344 Some(ref prefix) => format!("{}:", prefix),
345 None => String::from(""),
346 } + elem.name();
347 if name.as_bytes() != e.name() {
348 bail!(ErrorKind::InvalidElementClosed);
349 }
350 to.append_child(elem);
351 }
352 },
353 Event::Text(s) | Event::CData(s) => {
354 let text = s.unescape_and_decode(reader)?;
355 if text != "" {
356 let mut current_elem = stack.last_mut().unwrap();
357 current_elem.append_text_node(text);
358 }
359 },
360 Event::Eof => {
361 break;
362 },
363 Event::Comment { .. } |
364 Event::Decl { .. } |
365 Event::PI { .. } |
366 Event::DocType { .. } => (),
367 }
368 }
369 Ok(stack.pop().unwrap())
370 }
371
372 /// Output a document to a `Writer`.
373 pub fn write_to<W: Write>(&self, writer: &mut W) -> Result<()> {
374 write!(writer, "<?xml version=\"1.0\" encoding=\"utf-8\"?>")?;
375 self.write_to_inner(writer)
376 }
377
378 /// Like `write_to()` but without the `<?xml?>` prelude
379 pub fn write_to_inner<W: Write>(&self, writer: &mut W) -> Result<()> {
380 let name = match self.prefix {
381 None => Cow::Borrowed(&self.name),
382 Some(ref prefix) => Cow::Owned(format!("{}:{}", prefix, self.name)),
383 };
384 write!(writer, "<{}", name)?;
385
386 for (prefix, ns) in self.namespaces.declared_ns() {
387 match *prefix {
388 None => {
389 write!(writer, " xmlns=\"")?;
390 write_escaped(writer, ns)?;
391 write!(writer, "\"")?;
392 },
393 Some(ref prefix) => {
394 write!(writer, " xmlns:{}=\"", prefix)?;
395 write_escaped(writer, ns)?;
396 write!(writer, "\"")?;
397 },
398 }
399 }
400
401 for (key, value) in &self.attributes {
402 write!(writer, " {}=\"", key)?;
403 write_escaped(writer, value)?;
404 write!(writer, "\"")?;
405 }
406
407 if self.children.is_empty() {
408 write!(writer, " />")?;
409 return Ok(())
410 }
411
412 write!(writer, ">")?;
413
414 for child in &self.children {
415 child.write_to_inner(writer)?;
416 }
417
418 write!(writer, "</{}>", name)?;
419 Ok(())
420 }
421
422 /// Returns an iterator over references to every child node of this element.
423 ///
424 /// # Examples
425 ///
426 /// ```rust
427 /// use minidom::Element;
428 ///
429 /// let elem: Element = "<root>a<c1 />b<c2 />c</root>".parse().unwrap();
430 ///
431 /// let mut iter = elem.nodes();
432 ///
433 /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "a");
434 /// assert_eq!(iter.next().unwrap().as_element().unwrap().name(), "c1");
435 /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "b");
436 /// assert_eq!(iter.next().unwrap().as_element().unwrap().name(), "c2");
437 /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "c");
438 /// assert_eq!(iter.next(), None);
439 /// ```
440 #[inline] pub fn nodes(&self) -> Nodes {
441 self.children.iter()
442 }
443
444 /// Returns an iterator over mutable references to every child node of this element.
445 #[inline] pub fn nodes_mut(&mut self) -> NodesMut {
446 self.children.iter_mut()
447 }
448
449 /// Returns an iterator over references to every child element of this element.
450 ///
451 /// # Examples
452 ///
453 /// ```rust
454 /// use minidom::Element;
455 ///
456 /// let elem: Element = "<root>hello<child1 />this<child2 />is<child3 />ignored</root>".parse().unwrap();
457 ///
458 /// let mut iter = elem.children();
459 /// assert_eq!(iter.next().unwrap().name(), "child1");
460 /// assert_eq!(iter.next().unwrap().name(), "child2");
461 /// assert_eq!(iter.next().unwrap().name(), "child3");
462 /// assert_eq!(iter.next(), None);
463 /// ```
464 #[inline] pub fn children(&self) -> Children {
465 Children {
466 iter: self.children.iter(),
467 }
468 }
469
470 /// Returns an iterator over mutable references to every child element of this element.
471 #[inline] pub fn children_mut(&mut self) -> ChildrenMut {
472 ChildrenMut {
473 iter: self.children.iter_mut(),
474 }
475 }
476
477 /// Returns an iterator over references to every text node of this element.
478 ///
479 /// # Examples
480 ///
481 /// ```rust
482 /// use minidom::Element;
483 ///
484 /// let elem: Element = "<root>hello<c /> world!</root>".parse().unwrap();
485 ///
486 /// let mut iter = elem.texts();
487 /// assert_eq!(iter.next().unwrap(), "hello");
488 /// assert_eq!(iter.next().unwrap(), " world!");
489 /// assert_eq!(iter.next(), None);
490 /// ```
491 #[inline] pub fn texts(&self) -> Texts {
492 Texts {
493 iter: self.children.iter(),
494 }
495 }
496
497 /// Returns an iterator over mutable references to every text node of this element.
498 #[inline] pub fn texts_mut(&mut self) -> TextsMut {
499 TextsMut {
500 iter: self.children.iter_mut(),
501 }
502 }
503
504 /// Appends a child node to the `Element`, returning the appended node.
505 ///
506 /// # Examples
507 ///
508 /// ```rust
509 /// use minidom::Element;
510 ///
511 /// let mut elem = Element::bare("root");
512 ///
513 /// assert_eq!(elem.children().count(), 0);
514 ///
515 /// elem.append_child(Element::bare("child"));
516 ///
517 /// {
518 /// let mut iter = elem.children();
519 /// assert_eq!(iter.next().unwrap().name(), "child");
520 /// assert_eq!(iter.next(), None);
521 /// }
522 ///
523 /// let child = elem.append_child(Element::bare("new"));
524 ///
525 /// assert_eq!(child.name(), "new");
526 /// ```
527 pub fn append_child(&mut self, child: Element) -> &mut Element {
528 child.namespaces.set_parent(Rc::clone(&self.namespaces));
529
530 self.children.push(Node::Element(child));
531 if let Node::Element(ref mut cld) = *self.children.last_mut().unwrap() {
532 cld
533 } else {
534 unreachable!()
535 }
536 }
537
538 /// Appends a text node to an `Element`.
539 ///
540 /// # Examples
541 ///
542 /// ```rust
543 /// use minidom::Element;
544 ///
545 /// let mut elem = Element::bare("node");
546 ///
547 /// assert_eq!(elem.text(), "");
548 ///
549 /// elem.append_text_node("text");
550 ///
551 /// assert_eq!(elem.text(), "text");
552 /// ```
553 pub fn append_text_node<S: Into<String>>(&mut self, child: S) {
554 self.children.push(Node::Text(child.into()));
555 }
556
557 /// Appends a node to an `Element`.
558 ///
559 /// # Examples
560 ///
561 /// ```rust
562 /// use minidom::{Element, Node};
563 ///
564 /// let mut elem = Element::bare("node");
565 ///
566 /// elem.append_node(Node::Text("hello".to_owned()));
567 ///
568 /// assert_eq!(elem.text(), "hello");
569 /// ```
570 pub fn append_node(&mut self, node: Node) {
571 self.children.push(node);
572 }
573
574 /// Returns the concatenation of all text nodes in the `Element`.
575 ///
576 /// # Examples
577 ///
578 /// ```rust
579 /// use minidom::Element;
580 ///
581 /// let elem: Element = "<node>hello,<split /> world!</node>".parse().unwrap();
582 ///
583 /// assert_eq!(elem.text(), "hello, world!");
584 /// ```
585 pub fn text(&self) -> String {
586 self.texts().fold(String::new(), |ret, new| ret + new)
587 }
588
589 /// Returns a reference to the first child element with the specific name and namespace, if it
590 /// exists in the direct descendants of this `Element`, else returns `None`.
591 ///
592 /// # Examples
593 ///
594 /// ```rust
595 /// use minidom::Element;
596 ///
597 /// let elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
598 ///
599 /// assert!(elem.get_child("a", "ns").unwrap().is("a", "ns"));
600 /// assert!(elem.get_child("a", "other_ns").unwrap().is("a", "other_ns"));
601 /// assert!(elem.get_child("b", "ns").unwrap().is("b", "ns"));
602 /// assert_eq!(elem.get_child("c", "ns"), None);
603 /// assert_eq!(elem.get_child("b", "other_ns"), None);
604 /// assert_eq!(elem.get_child("a", "inexistent_ns"), None);
605 /// ```
606 pub fn get_child<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> Option<&Element> {
607 for fork in &self.children {
608 if let Node::Element(ref e) = *fork {
609 if e.is(name.as_ref(), namespace.as_ref()) {
610 return Some(e);
611 }
612 }
613 }
614 None
615 }
616
617 /// Returns a mutable reference to the first child element with the specific name and namespace,
618 /// if it exists in the direct descendants of this `Element`, else returns `None`.
619 pub fn get_child_mut<N: AsRef<str>, NS: AsRef<str>>(&mut self, name: N, namespace: NS) -> Option<&mut Element> {
620 for fork in &mut self.children {
621 if let Node::Element(ref mut e) = *fork {
622 if e.is(name.as_ref(), namespace.as_ref()) {
623 return Some(e);
624 }
625 }
626 }
627 None
628 }
629
630 /// Returns whether a specific child with this name and namespace exists in the direct
631 /// descendants of the `Element`.
632 ///
633 /// # Examples
634 ///
635 /// ```rust
636 /// use minidom::Element;
637 ///
638 /// let elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
639 ///
640 /// assert_eq!(elem.has_child("a", "other_ns"), true);
641 /// assert_eq!(elem.has_child("a", "ns"), true);
642 /// assert_eq!(elem.has_child("a", "inexistent_ns"), false);
643 /// assert_eq!(elem.has_child("b", "ns"), true);
644 /// assert_eq!(elem.has_child("b", "other_ns"), false);
645 /// assert_eq!(elem.has_child("b", "inexistent_ns"), false);
646 /// ```
647 pub fn has_child<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> bool {
648 self.get_child(name, namespace).is_some()
649 }
650}
651
652fn split_element_name<S: AsRef<str>>(s: S) -> Result<(Option<String>, String)> {
653 let name_parts = s.as_ref().split(':').collect::<Vec<&str>>();
654 match name_parts.len() {
655 2 => Ok((Some(name_parts[0].to_owned()), name_parts[1].to_owned())),
656 1 => Ok((None, name_parts[0].to_owned())),
657 _ => bail!(ErrorKind::InvalidElement),
658 }
659}
660
661fn build_element<R: BufRead>(reader: &EventReader<R>, event: &BytesStart) -> Result<Element> {
662 let mut namespaces = BTreeMap::new();
663 let attributes = event.attributes()
664 .map(|o| {
665 let o = o?;
666 let key = str::from_utf8(o.key)?.to_owned();
667 let value = o.unescape_and_decode_value(reader)?;
668 Ok((key, value))
669 })
670 .filter(|o| {
671 match *o {
672 Ok((ref key, ref value)) if key == "xmlns" => {
673 namespaces.insert(None, value.to_owned());
674 false
675 },
676 Ok((ref key, ref value)) if key.starts_with("xmlns:") => {
677 namespaces.insert(Some(key[6..].to_owned()), value.to_owned());
678 false
679 },
680 _ => true,
681 }
682 })
683 .collect::<Result<BTreeMap<String, String>>>()?;
684
685 let (prefix, name) = split_element_name(str::from_utf8(event.name())?)?;
686 let element = Element::new(name, prefix, namespaces, attributes, Vec::new());
687 Ok(element)
688}
689
690/// An iterator over references to child elements of an `Element`.
691pub struct Children<'a> {
692 iter: slice::Iter<'a, Node>,
693}
694
695impl<'a> Iterator for Children<'a> {
696 type Item = &'a Element;
697
698 fn next(&mut self) -> Option<&'a Element> {
699 for item in &mut self.iter {
700 if let Node::Element(ref child) = *item {
701 return Some(child);
702 }
703 }
704 None
705 }
706}
707
708/// An iterator over mutable references to child elements of an `Element`.
709pub struct ChildrenMut<'a> {
710 iter: slice::IterMut<'a, Node>,
711}
712
713impl<'a> Iterator for ChildrenMut<'a> {
714 type Item = &'a mut Element;
715
716 fn next(&mut self) -> Option<&'a mut Element> {
717 for item in &mut self.iter {
718 if let Node::Element(ref mut child) = *item {
719 return Some(child);
720 }
721 }
722 None
723 }
724}
725
726/// An iterator over references to child text nodes of an `Element`.
727pub struct Texts<'a> {
728 iter: slice::Iter<'a, Node>,
729}
730
731impl<'a> Iterator for Texts<'a> {
732 type Item = &'a str;
733
734 fn next(&mut self) -> Option<&'a str> {
735 for item in &mut self.iter {
736 if let Node::Text(ref child) = *item {
737 return Some(child);
738 }
739 }
740 None
741 }
742}
743
744/// An iterator over mutable references to child text nodes of an `Element`.
745pub struct TextsMut<'a> {
746 iter: slice::IterMut<'a, Node>,
747}
748
749impl<'a> Iterator for TextsMut<'a> {
750 type Item = &'a mut String;
751
752 fn next(&mut self) -> Option<&'a mut String> {
753 for item in &mut self.iter {
754 if let Node::Text(ref mut child) = *item {
755 return Some(child);
756 }
757 }
758 None
759 }
760}
761
762/// An iterator over references to all child nodes of an `Element`.
763pub type Nodes<'a> = slice::Iter<'a, Node>;
764
765/// An iterator over mutable references to all child nodes of an `Element`.
766pub type NodesMut<'a> = slice::IterMut<'a, Node>;
767
768/// An iterator over the attributes of an `Element`.
769pub struct Attrs<'a> {
770 iter: btree_map::Iter<'a, String, String>,
771}
772
773impl<'a> Iterator for Attrs<'a> {
774 type Item = (&'a str, &'a str);
775
776 fn next(&mut self) -> Option<Self::Item> {
777 self.iter.next().map(|(x, y)| (x.as_ref(), y.as_ref()))
778 }
779}
780
781/// An iterator over the attributes of an `Element`, with the values mutable.
782pub struct AttrsMut<'a> {
783 iter: btree_map::IterMut<'a, String, String>,
784}
785
786impl<'a> Iterator for AttrsMut<'a> {
787 type Item = (&'a str, &'a mut String);
788
789 fn next(&mut self) -> Option<Self::Item> {
790 self.iter.next().map(|(x, y)| (x.as_ref(), y))
791 }
792}
793
794/// A builder for `Element`s.
795pub struct ElementBuilder {
796 root: Element,
797 namespaces: BTreeMap<Option<String>, String>,
798}
799
800impl ElementBuilder {
801 /// Sets the namespace.
802 pub fn ns<S: Into<String>>(mut self, namespace: S) -> ElementBuilder {
803 self.namespaces
804 .insert(self.root.prefix.clone(), namespace.into());
805 self
806 }
807
808 /// Sets an attribute.
809 pub fn attr<S: Into<String>, V: IntoAttributeValue>(mut self, name: S, value: V) -> ElementBuilder {
810 self.root.set_attr(name, value);
811 self
812 }
813
814 /// Appends anything implementing `IntoElements` into the tree.
815 pub fn append<T: IntoElements>(mut self, into: T) -> ElementBuilder {
816 {
817 let mut emitter = ElementEmitter::new(&mut self.root);
818 into.into_elements(&mut emitter);
819 }
820 self
821 }
822
823 /// Builds the `Element`.
824 pub fn build(self) -> Element {
825 let mut element = self.root;
826 // Set namespaces
827 element.namespaces = Rc::new(NamespaceSet::from(self.namespaces));
828 // Propagate namespaces
829 for node in &element.children {
830 if let Node::Element(ref e) = *node {
831 e.namespaces.set_parent(Rc::clone(&element.namespaces));
832 }
833 }
834
835 element
836 }
837}
838
839#[cfg(test)]
840#[test]
841fn test_element_new() {
842 use std::iter::FromIterator;
843
844 let elem = Element::new( "name".to_owned()
845 , None
846 , Some("namespace".to_owned())
847 , BTreeMap::from_iter(vec![ ("name".to_string(), "value".to_string()) ].into_iter() )
848 , Vec::new() );
849
850 assert_eq!(elem.name(), "name");
851 assert_eq!(elem.ns(), Some("namespace".to_owned()));
852 assert_eq!(elem.attr("name"), Some("value"));
853 assert_eq!(elem.attr("inexistent"), None);
854}
855
856#[test]
857fn test_from_reader_simple() {
858 let xml = "<foo></foo>";
859 let mut reader = EventReader::from_str(xml);
860 let elem = Element::from_reader(&mut reader);
861
862 let elem2 = Element::builder("foo").build();
863
864 assert_eq!(elem.unwrap(), elem2);
865}
866
867#[test]
868fn test_from_reader_nested() {
869 let xml = "<foo><bar baz='qxx' /></foo>";
870 let mut reader = EventReader::from_str(xml);
871 let elem = Element::from_reader(&mut reader);
872
873 let nested = Element::builder("bar")
874 .attr("baz", "qxx")
875 .build();
876 let elem2 = Element::builder("foo")
877 .append(nested)
878 .build();
879
880 assert_eq!(elem.unwrap(), elem2);
881}
882
883#[test]
884fn test_from_reader_with_prefix() {
885 let xml = "<foo><prefix:bar baz='qxx' /></foo>";
886 let mut reader = EventReader::from_str(xml);
887 let elem = Element::from_reader(&mut reader);
888
889 let nested = Element::builder("prefix:bar")
890 .attr("baz", "qxx")
891 .build();
892 let elem2 = Element::builder("foo")
893 .append(nested)
894 .build();
895
896 assert_eq!(elem.unwrap(), elem2);
897}