add ElementBuilder, add tests, some fixes and cleanups

src/jid.rs

@@ -147,7 +147,7 @@ impl Jid {
 }
 
 #[cfg(test)]
-mod test {
+mod tests {
     use super::*;
 
     #[test]

src/tree.rs

@@ -2,16 +2,18 @@
 
 use std::io::prelude::*;
 
+use std::convert::From;
+
 use std::fmt;
 
 use xml::name::{OwnedName, Name};
-use xml::reader::{XmlEvent, EventReader};
+use xml::reader::{XmlEvent as ReaderEvent, EventReader};
 use xml::writer::{XmlEvent as WriterEvent, EventWriter};
 use xml::attribute::OwnedAttribute;
 
 use error::Error;
 
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 pub struct Element {
     name: OwnedName,
     attributes: Vec<OwnedAttribute>,
@@ -40,7 +42,7 @@ impl fmt::Debug for Element {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Fork {
     Element(Element),
     Text(String),
@@ -55,16 +57,41 @@ impl Element {
         }
     }
 
+    pub fn builder<S: Into<String>>(name: S) -> ElementBuilder {
+        ElementBuilder {
+            name: OwnedName::local(name),
+            attributes: Vec::new(),
+        }
+    }
+
+    pub fn tag(&self) -> &str {
+        &self.name.local_name
+    }
+
+    pub fn ns(&self) -> Option<&str> {
+        self.name.namespace.as_ref()
+                           .map(String::as_ref)
+    }
+
+    pub fn attr(&self, key: &str) -> Option<&str> {
+        for attr in &self.attributes {
+            if attr.name.local_name == key {
+                return Some(&attr.value);
+            }
+        }
+        None
+    }
+
     pub fn from_reader<R: Read>(reader: &mut EventReader<R>) -> Result<Element, Error> {
         loop {
             let e = reader.next()?;
             match e {
-                XmlEvent::StartElement { name, attributes, .. } => {
+                ReaderEvent::StartElement { name, attributes, .. } => {
                     let mut root = Element::new(name, attributes);
                     root.from_reader_inner(reader);
                     return Ok(root);
                 },
-                XmlEvent::EndDocument => {
+                ReaderEvent::EndDocument => {
                     return Err(Error::EndOfDocument);
                 },
                 _ => () // TODO: may need more errors
@@ -76,22 +103,22 @@ impl Element {
         loop {
             let e = reader.next()?;
             match e {
-                XmlEvent::StartElement { name, attributes, .. } => {
+                ReaderEvent::StartElement { name, attributes, .. } => {
                     let elem = Element::new(name, attributes);
                     let elem_ref = self.append_child(elem);
                     elem_ref.from_reader_inner(reader);
                 },
-                XmlEvent::EndElement { .. } => {
+                ReaderEvent::EndElement { .. } => {
                     // TODO: may want to check whether we're closing the correct element
                     return Ok(());
                 },
-                XmlEvent::Characters(s) => {
+                ReaderEvent::Characters(s) => {
                     self.append_text_node(s);
                 },
-                XmlEvent::CData(s) => {
+                ReaderEvent::CData(s) => {
                     self.append_text_node(s);
                 },
-                XmlEvent::EndDocument => {
+                ReaderEvent::EndDocument => {
                     return Err(Error::EndOfDocument);
                 },
                 _ => (), // TODO: may need to implement more
@@ -100,7 +127,13 @@ impl Element {
     }
 
     pub fn write_to<W: Write>(&self, writer: &mut EventWriter<W>) -> Result<(), Error> {
-        let start = WriterEvent::start_element(self.name.borrow());
+        let mut start = WriterEvent::start_element(self.name.borrow());
+        if let Some(ref ns) = self.name.namespace {
+            start = start.default_ns(ns.as_ref());
+        }
+        for attr in &self.attributes { // TODO: I think this could be done a lot more efficiently
+            start = start.attr(attr.name.borrow(), &attr.value);
+        }
         writer.write(start)?;
         for child in &self.children {
             match *child {
@@ -134,8 +167,8 @@ impl Element {
         }
     }
 
-    pub fn append_text_node(&mut self, child: String) {
-        self.children.push(Fork::Text(child));
+    pub fn append_text_node<S: Into<String>>(&mut self, child: S) {
+        self.children.push(Fork::Text(child.into()));
     }
 
     pub fn text(&self) -> &str {
@@ -162,3 +195,85 @@ pub struct Children<'a> {
 pub struct ChildrenMut<'a> {
     elem: &'a mut Element,
 }
+
+pub struct ElementBuilder {
+    name: OwnedName,
+    attributes: Vec<OwnedAttribute>,
+}
+
+impl ElementBuilder {
+    pub fn ns<S: Into<String>>(mut self, namespace: S) -> ElementBuilder {
+        self.name.namespace = Some(namespace.into());
+        self
+    }
+
+    pub fn attr<S: Into<String>, V: Into<String>>(mut self, name: S, value: V) -> ElementBuilder {
+        self.attributes.push(OwnedAttribute::new(OwnedName::local(name), value));
+        self
+    }
+
+    pub fn attr_ns<S: Into<String>, N: Into<String>, V: Into<String>>(mut self, name: S, namespace: N, value: V) -> ElementBuilder {
+        self.attributes.push(OwnedAttribute::new(OwnedName::qualified::<_, _, &'static str>(name, namespace, None), value));
+        self
+    }
+
+    pub fn build(self) -> Element {
+        Element::new(self.name, self.attributes)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const TEST_STRING: &'static str = r#"<?xml version="1.0" encoding="utf-8"?><root xmlns="root_ns" a="b">meow<child c="d" /><child xmlns="child_ns" d="e" />nya</root>"#;
+
+    fn build_test_tree() -> Element {
+        let mut root = Element::builder("root")
+                               .ns("root_ns")
+                               .attr("a", "b")
+                               .build();
+        root.append_text_node("meow");
+        let child = Element::builder("child")
+                            .attr("c", "d")
+                            .build();
+        root.append_child(child);
+        let other_child = Element::builder("child")
+                                  .ns("child_ns")
+                                  .attr("d", "e")
+                                  .build();
+        root.append_child(other_child);
+        root.append_text_node("nya");
+        root
+    }
+
+    #[test]
+    fn reader_works() {
+        use std::io::Cursor;
+        let mut reader = EventReader::new(Cursor::new(TEST_STRING));
+        // TODO: fix a bunch of namespace stuff so this test passes
+        assert_eq!(Element::from_reader(&mut reader).unwrap(), build_test_tree());
+    }
+
+    #[test]
+    fn writer_works() {
+        let root = build_test_tree();
+        let mut out = Vec::new();
+        {
+            let mut writer = EventWriter::new(&mut out);
+            root.write_to(&mut writer);
+        }
+        assert_eq!(String::from_utf8(out).unwrap(), TEST_STRING);
+    }
+
+    #[test]
+    fn builder_works() {
+        let elem = Element::builder("a")
+                           .ns("b")
+                           .attr("c", "d")
+                           .build();
+        assert_eq!(elem.tag(), "a");
+        assert_eq!(elem.ns(), Some("b"));
+        assert_eq!(elem.attr("c"), Some("d"));
+    }
+}