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".to_owned()));
205 /// ```
206 pub fn prefix(&self) -> Option<String> {
207 self.prefix.clone()
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 _ => (), // TODO: may need more errors
315 }
316 };
317
318 let mut stack = vec![root];
319
320 loop {
321 match reader.read_event(&mut buf)? {
322 Event::Empty(ref e) => {
323 let elem = build_element(reader, e)?;
324 // Since there is no Event::End after, directly append it to the current node
325 stack.last_mut().unwrap().append_child(elem);
326 },
327 Event::Start(ref e) => {
328 let elem = build_element(reader, e)?;
329 stack.push(elem);
330 },
331 Event::End(ref e) => {
332 if stack.len() <= 1 {
333 break;
334 }
335 let elem = stack.pop().unwrap();
336 if let Some(to) = stack.last_mut() {
337 let name = match elem.prefix() {
338 Some(ref prefix) => format!("{}:", prefix.clone()),
339 None => String::from(""),
340 } + elem.name();
341 if name.as_bytes() != e.name() {
342 bail!(ErrorKind::InvalidElementClosed);
343 }
344 to.append_child(elem);
345 }
346 },
347 Event::Text(s) | Event::CData(s) => {
348 let text = s.unescape_and_decode(reader)?;
349 if text != "" {
350 let mut current_elem = stack.last_mut().unwrap();
351 current_elem.append_text_node(text);
352 }
353 },
354 Event::Eof => {
355 break;
356 },
357 _ => (), // TODO: may need to implement more
358 }
359 }
360 Ok(stack.pop().unwrap())
361 }
362
363 /// Output a document to a `Writer`.
364 pub fn write_to<W: Write>(&self, writer: &mut W) -> Result<()> {
365 write!(writer, "<?xml version=\"1.0\" encoding=\"utf-8\"?>")?;
366 self.write_to_inner(writer)
367 }
368
369 /// Like `write_to()` but without the `<?xml?>` prelude
370 pub fn write_to_inner<W: Write>(&self, writer: &mut W) -> Result<()> {
371 let name = match self.prefix {
372 None => Cow::Borrowed(&self.name),
373 Some(ref prefix) => Cow::Owned(format!("{}:{}", prefix, self.name)),
374 };
375 write!(writer, "<{}", name)?;
376
377 for (prefix, ns) in self.namespaces.declared_ns() {
378 match *prefix {
379 None => {
380 write!(writer, " xmlns=\"")?;
381 write_escaped(writer, ns)?;
382 write!(writer, "\"")?;
383 },
384 Some(ref prefix) => {
385 write!(writer, " xmlns:{}=\"", prefix)?;
386 write_escaped(writer, ns)?;
387 write!(writer, "\"")?;
388 },
389 }
390 }
391
392 for (key, value) in &self.attributes {
393 write!(writer, " {}=\"", key)?;
394 write_escaped(writer, value)?;
395 write!(writer, "\"")?;
396 }
397
398 if self.children.is_empty() {
399 write!(writer, " />")?;
400 return Ok(())
401 }
402
403 write!(writer, ">")?;
404
405 for child in &self.children {
406 child.write_to_inner(writer)?;
407 }
408
409 write!(writer, "</{}>", name)?;
410 Ok(())
411 }
412
413 /// Returns an iterator over references to every child node of this element.
414 ///
415 /// # Examples
416 ///
417 /// ```rust
418 /// use minidom::Element;
419 ///
420 /// let elem: Element = "<root>a<c1 />b<c2 />c</root>".parse().unwrap();
421 ///
422 /// let mut iter = elem.nodes();
423 ///
424 /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "a");
425 /// assert_eq!(iter.next().unwrap().as_element().unwrap().name(), "c1");
426 /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "b");
427 /// assert_eq!(iter.next().unwrap().as_element().unwrap().name(), "c2");
428 /// assert_eq!(iter.next().unwrap().as_text().unwrap(), "c");
429 /// assert_eq!(iter.next(), None);
430 /// ```
431 #[inline] pub fn nodes(&self) -> Nodes {
432 self.children.iter()
433 }
434
435 /// Returns an iterator over mutable references to every child node of this element.
436 #[inline] pub fn nodes_mut(&mut self) -> NodesMut {
437 self.children.iter_mut()
438 }
439
440 /// Returns an iterator over references to every child element of this element.
441 ///
442 /// # Examples
443 ///
444 /// ```rust
445 /// use minidom::Element;
446 ///
447 /// let elem: Element = "<root>hello<child1 />this<child2 />is<child3 />ignored</root>".parse().unwrap();
448 ///
449 /// let mut iter = elem.children();
450 /// assert_eq!(iter.next().unwrap().name(), "child1");
451 /// assert_eq!(iter.next().unwrap().name(), "child2");
452 /// assert_eq!(iter.next().unwrap().name(), "child3");
453 /// assert_eq!(iter.next(), None);
454 /// ```
455 #[inline] pub fn children(&self) -> Children {
456 Children {
457 iter: self.children.iter(),
458 }
459 }
460
461 /// Returns an iterator over mutable references to every child element of this element.
462 #[inline] pub fn children_mut(&mut self) -> ChildrenMut {
463 ChildrenMut {
464 iter: self.children.iter_mut(),
465 }
466 }
467
468 /// Returns an iterator over references to every text node of this element.
469 ///
470 /// # Examples
471 ///
472 /// ```rust
473 /// use minidom::Element;
474 ///
475 /// let elem: Element = "<root>hello<c /> world!</root>".parse().unwrap();
476 ///
477 /// let mut iter = elem.texts();
478 /// assert_eq!(iter.next().unwrap(), "hello");
479 /// assert_eq!(iter.next().unwrap(), " world!");
480 /// assert_eq!(iter.next(), None);
481 /// ```
482 #[inline] pub fn texts(&self) -> Texts {
483 Texts {
484 iter: self.children.iter(),
485 }
486 }
487
488 /// Returns an iterator over mutable references to every text node of this element.
489 #[inline] pub fn texts_mut(&mut self) -> TextsMut {
490 TextsMut {
491 iter: self.children.iter_mut(),
492 }
493 }
494
495 /// Appends a child node to the `Element`, returning the appended node.
496 ///
497 /// # Examples
498 ///
499 /// ```rust
500 /// use minidom::Element;
501 ///
502 /// let mut elem = Element::bare("root");
503 ///
504 /// assert_eq!(elem.children().count(), 0);
505 ///
506 /// elem.append_child(Element::bare("child"));
507 ///
508 /// {
509 /// let mut iter = elem.children();
510 /// assert_eq!(iter.next().unwrap().name(), "child");
511 /// assert_eq!(iter.next(), None);
512 /// }
513 ///
514 /// let child = elem.append_child(Element::bare("new"));
515 ///
516 /// assert_eq!(child.name(), "new");
517 /// ```
518 pub fn append_child(&mut self, child: Element) -> &mut Element {
519 child.namespaces.set_parent(Rc::clone(&self.namespaces));
520
521 self.children.push(Node::Element(child));
522 if let Node::Element(ref mut cld) = *self.children.last_mut().unwrap() {
523 cld
524 } else {
525 unreachable!()
526 }
527 }
528
529 /// Appends a text node to an `Element`.
530 ///
531 /// # Examples
532 ///
533 /// ```rust
534 /// use minidom::Element;
535 ///
536 /// let mut elem = Element::bare("node");
537 ///
538 /// assert_eq!(elem.text(), "");
539 ///
540 /// elem.append_text_node("text");
541 ///
542 /// assert_eq!(elem.text(), "text");
543 /// ```
544 pub fn append_text_node<S: Into<String>>(&mut self, child: S) {
545 self.children.push(Node::Text(child.into()));
546 }
547
548 /// Appends a node to an `Element`.
549 ///
550 /// # Examples
551 ///
552 /// ```rust
553 /// use minidom::{Element, Node};
554 ///
555 /// let mut elem = Element::bare("node");
556 ///
557 /// elem.append_node(Node::Text("hello".to_owned()));
558 ///
559 /// assert_eq!(elem.text(), "hello");
560 /// ```
561 pub fn append_node(&mut self, node: Node) {
562 self.children.push(node);
563 }
564
565 /// Returns the concatenation of all text nodes in the `Element`.
566 ///
567 /// # Examples
568 ///
569 /// ```rust
570 /// use minidom::Element;
571 ///
572 /// let elem: Element = "<node>hello,<split /> world!</node>".parse().unwrap();
573 ///
574 /// assert_eq!(elem.text(), "hello, world!");
575 /// ```
576 pub fn text(&self) -> String {
577 self.texts().fold(String::new(), |ret, new| ret + new)
578 }
579
580 /// Returns a reference to the first child element with the specific name and namespace, if it
581 /// exists in the direct descendants of this `Element`, else returns `None`.
582 ///
583 /// # Examples
584 ///
585 /// ```rust
586 /// use minidom::Element;
587 ///
588 /// let elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
589 ///
590 /// assert!(elem.get_child("a", "ns").unwrap().is("a", "ns"));
591 /// assert!(elem.get_child("a", "other_ns").unwrap().is("a", "other_ns"));
592 /// assert!(elem.get_child("b", "ns").unwrap().is("b", "ns"));
593 /// assert_eq!(elem.get_child("c", "ns"), None);
594 /// assert_eq!(elem.get_child("b", "other_ns"), None);
595 /// assert_eq!(elem.get_child("a", "inexistent_ns"), None);
596 /// ```
597 pub fn get_child<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> Option<&Element> {
598 for fork in &self.children {
599 if let Node::Element(ref e) = *fork {
600 if e.is(name.as_ref(), namespace.as_ref()) {
601 return Some(e);
602 }
603 }
604 }
605 None
606 }
607
608 /// Returns a mutable reference to the first child element with the specific name and namespace,
609 /// if it exists in the direct descendants of this `Element`, else returns `None`.
610 pub fn get_child_mut<N: AsRef<str>, NS: AsRef<str>>(&mut self, name: N, namespace: NS) -> Option<&mut Element> {
611 for fork in &mut self.children {
612 if let Node::Element(ref mut e) = *fork {
613 if e.is(name.as_ref(), namespace.as_ref()) {
614 return Some(e);
615 }
616 }
617 }
618 None
619 }
620
621 /// Returns whether a specific child with this name and namespace exists in the direct
622 /// descendants of the `Element`.
623 ///
624 /// # Examples
625 ///
626 /// ```rust
627 /// use minidom::Element;
628 ///
629 /// let elem: Element = r#"<node xmlns="ns"><a /><a xmlns="other_ns" /><b /></node>"#.parse().unwrap();
630 ///
631 /// assert_eq!(elem.has_child("a", "other_ns"), true);
632 /// assert_eq!(elem.has_child("a", "ns"), true);
633 /// assert_eq!(elem.has_child("a", "inexistent_ns"), false);
634 /// assert_eq!(elem.has_child("b", "ns"), true);
635 /// assert_eq!(elem.has_child("b", "other_ns"), false);
636 /// assert_eq!(elem.has_child("b", "inexistent_ns"), false);
637 /// ```
638 pub fn has_child<N: AsRef<str>, NS: AsRef<str>>(&self, name: N, namespace: NS) -> bool {
639 self.get_child(name, namespace).is_some()
640 }
641}
642
643fn split_element_name<S: AsRef<str>>(s: S) -> Result<(Option<String>, String)> {
644 let name_parts = s.as_ref().split(':').collect::<Vec<&str>>();
645 match name_parts.len() {
646 2 => Ok((Some(name_parts[0].to_owned()), name_parts[1].to_owned())),
647 1 => Ok((None, name_parts[0].to_owned())),
648 _ => bail!(ErrorKind::InvalidElement),
649 }
650}
651
652fn build_element<R: BufRead>(reader: &EventReader<R>, event: &BytesStart) -> Result<Element> {
653 let mut namespaces = BTreeMap::new();
654 let attributes = event.attributes()
655 .map(|o| {
656 let o = o?;
657 let key = str::from_utf8(o.key)?.to_owned();
658 let value = o.unescape_and_decode_value(reader)?;
659 Ok((key, value))
660 })
661 .filter(|o| {
662 match *o {
663 Ok((ref key, ref value)) if key == "xmlns" => {
664 namespaces.insert(None, value.to_owned());
665 false
666 },
667 Ok((ref key, ref value)) if key.starts_with("xmlns:") => {
668 namespaces.insert(Some(key[6..].to_owned()), value.to_owned());
669 false
670 },
671 _ => true,
672 }
673 })
674 .collect::<Result<BTreeMap<String, String>>>()?;
675
676 let (prefix, name) = split_element_name(str::from_utf8(event.name())?)?;
677 let element = Element::new(name, prefix, namespaces, attributes, Vec::new());
678 Ok(element)
679}
680
681/// An iterator over references to child elements of an `Element`.
682pub struct Children<'a> {
683 iter: slice::Iter<'a, Node>,
684}
685
686impl<'a> Iterator for Children<'a> {
687 type Item = &'a Element;
688
689 fn next(&mut self) -> Option<&'a Element> {
690 for item in &mut self.iter {
691 if let Node::Element(ref child) = *item {
692 return Some(child);
693 }
694 }
695 None
696 }
697}
698
699/// An iterator over mutable references to child elements of an `Element`.
700pub struct ChildrenMut<'a> {
701 iter: slice::IterMut<'a, Node>,
702}
703
704impl<'a> Iterator for ChildrenMut<'a> {
705 type Item = &'a mut Element;
706
707 fn next(&mut self) -> Option<&'a mut Element> {
708 for item in &mut self.iter {
709 if let Node::Element(ref mut child) = *item {
710 return Some(child);
711 }
712 }
713 None
714 }
715}
716
717/// An iterator over references to child text nodes of an `Element`.
718pub struct Texts<'a> {
719 iter: slice::Iter<'a, Node>,
720}
721
722impl<'a> Iterator for Texts<'a> {
723 type Item = &'a str;
724
725 fn next(&mut self) -> Option<&'a str> {
726 for item in &mut self.iter {
727 if let Node::Text(ref child) = *item {
728 return Some(child);
729 }
730 }
731 None
732 }
733}
734
735/// An iterator over mutable references to child text nodes of an `Element`.
736pub struct TextsMut<'a> {
737 iter: slice::IterMut<'a, Node>,
738}
739
740impl<'a> Iterator for TextsMut<'a> {
741 type Item = &'a mut String;
742
743 fn next(&mut self) -> Option<&'a mut String> {
744 for item in &mut self.iter {
745 if let Node::Text(ref mut child) = *item {
746 return Some(child);
747 }
748 }
749 None
750 }
751}
752
753/// An iterator over references to all child nodes of an `Element`.
754pub type Nodes<'a> = slice::Iter<'a, Node>;
755
756/// An iterator over mutable references to all child nodes of an `Element`.
757pub type NodesMut<'a> = slice::IterMut<'a, Node>;
758
759/// An iterator over the attributes of an `Element`.
760pub struct Attrs<'a> {
761 iter: btree_map::Iter<'a, String, String>,
762}
763
764impl<'a> Iterator for Attrs<'a> {
765 type Item = (&'a str, &'a str);
766
767 fn next(&mut self) -> Option<Self::Item> {
768 self.iter.next().map(|(x, y)| (x.as_ref(), y.as_ref()))
769 }
770}
771
772/// An iterator over the attributes of an `Element`, with the values mutable.
773pub struct AttrsMut<'a> {
774 iter: btree_map::IterMut<'a, String, String>,
775}
776
777impl<'a> Iterator for AttrsMut<'a> {
778 type Item = (&'a str, &'a mut String);
779
780 fn next(&mut self) -> Option<Self::Item> {
781 self.iter.next().map(|(x, y)| (x.as_ref(), y))
782 }
783}
784
785/// A builder for `Element`s.
786pub struct ElementBuilder {
787 root: Element,
788 namespaces: BTreeMap<Option<String>, String>,
789}
790
791impl ElementBuilder {
792 /// Sets the namespace.
793 pub fn ns<S: Into<String>>(mut self, namespace: S) -> ElementBuilder {
794 self.namespaces
795 .insert(self.root.prefix.clone(), namespace.into());
796 self
797 }
798
799 /// Sets an attribute.
800 pub fn attr<S: Into<String>, V: IntoAttributeValue>(mut self, name: S, value: V) -> ElementBuilder {
801 self.root.set_attr(name, value);
802 self
803 }
804
805 /// Appends anything implementing `IntoElements` into the tree.
806 pub fn append<T: IntoElements>(mut self, into: T) -> ElementBuilder {
807 {
808 let mut emitter = ElementEmitter::new(&mut self.root);
809 into.into_elements(&mut emitter);
810 }
811 self
812 }
813
814 /// Builds the `Element`.
815 pub fn build(self) -> Element {
816 let mut element = self.root;
817 // Set namespaces
818 element.namespaces = Rc::new(NamespaceSet::from(self.namespaces));
819 // Propagate namespaces
820 for node in &element.children {
821 if let Node::Element(ref e) = *node {
822 e.namespaces.set_parent(Rc::clone(&element.namespaces));
823 }
824 }
825
826 element
827 }
828}
829
830#[cfg(test)]
831#[test]
832fn test_element_new() {
833 use std::iter::FromIterator;
834
835 let elem = Element::new( "name".to_owned()
836 , None
837 , Some("namespace".to_owned())
838 , BTreeMap::from_iter(vec![ ("name".to_string(), "value".to_string()) ].into_iter() )
839 , Vec::new() );
840
841 assert_eq!(elem.name(), "name");
842 assert_eq!(elem.ns(), Some("namespace".to_owned()));
843 assert_eq!(elem.attr("name"), Some("value"));
844 assert_eq!(elem.attr("inexistent"), None);
845}
846
847#[test]
848fn test_from_reader_simple() {
849 let xml = "<foo></foo>";
850 let mut reader = EventReader::from_str(xml);
851 let elem = Element::from_reader(&mut reader);
852
853 let elem2 = Element::builder("foo").build();
854
855 assert_eq!(elem.unwrap(), elem2);
856}
857
858#[test]
859fn test_from_reader_nested() {
860 let xml = "<foo><bar baz='qxx' /></foo>";
861 let mut reader = EventReader::from_str(xml);
862 let elem = Element::from_reader(&mut reader);
863
864 let nested = Element::builder("bar")
865 .attr("baz", "qxx")
866 .build();
867 let elem2 = Element::builder("foo")
868 .append(nested)
869 .build();
870
871 assert_eq!(elem.unwrap(), elem2);
872}
873
874#[test]
875fn test_from_reader_with_prefix() {
876 let xml = "<foo><prefix:bar baz='qxx' /></foo>";
877 let mut reader = EventReader::from_str(xml);
878 let elem = Element::from_reader(&mut reader);
879
880 let nested = Element::builder("prefix:bar")
881 .attr("baz", "qxx")
882 .build();
883 let elem2 = Element::builder("foo")
884 .append(nested)
885 .build();
886
887 assert_eq!(elem.unwrap(), elem2);
888}