Use a BTreeMap<String, String> instead of a Vec<Attribute> to store attributes

This way we don't need to reimplement PartialEq for Element. It's also
way easier to get an attribute by name as we don't need to iterate over
every attribute to see if it exists.

The only side effect is that now, in the Debug output, attributes are
automatically sorted by names instead of being sorted by insertion
order.

Fixes #4
This commit is contained in:
Bastien Orivel 2017-04-26 23:44:58 +02:00
commit f87e2442d4
4 changed files with 29 additions and 95 deletions

View file

@ -2,13 +2,13 @@
use std::io::prelude::*;
use std::io::Cursor;
use std::collections::BTreeMap;
use std::iter::FromIterator;
use std::fmt;
use error::Error;
use attribute::Attribute;
use xml::reader::{XmlEvent as ReaderEvent, EventReader};
use xml::writer::{XmlEvent as WriterEvent, EventWriter};
use xml::name::Name;
@ -20,28 +20,15 @@ use std::slice;
use convert::{IntoElements, IntoAttributeValue, ElementEmitter};
#[derive(Clone, Eq)]
#[derive(Clone, PartialEq, Eq)]
/// A struct representing a DOM Element.
pub struct Element {
name: String,
namespace: Option<String>,
attributes: Vec<Attribute>,
attributes: BTreeMap<String, String>,
children: Vec<Node>,
}
impl PartialEq for Element {
fn eq(&self, other: &Element) -> bool {
let mut my_attr = self.attributes.clone();
my_attr.sort();
let mut other_attr = other.attributes.clone();
other_attr.sort();
self.name == other.name &&
self.namespace == other.namespace &&
my_attr == other_attr &&
self.children == other.children
}
}
impl fmt::Debug for Element {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
@ -50,7 +37,7 @@ impl fmt::Debug for Element {
write!(fmt, " xmlns=\"{}\"", ns)?;
}
for attr in &self.attributes {
write!(fmt, " {}", attr)?;
write!(fmt, " {}=\"{}\"", attr.0, attr.1)?;
}
if self.children.is_empty() {
write!(fmt, "/>")?;
@ -92,7 +79,7 @@ pub enum Node {
}
impl Element {
fn new(name: String, namespace: Option<String>, attributes: Vec<Attribute>, children: Vec<Node>) -> Element {
fn new(name: String, namespace: Option<String>, attributes: BTreeMap<String, String>, children: Vec<Node>) -> Element {
Element {
name: name,
namespace: namespace,
@ -122,7 +109,7 @@ impl Element {
/// ```
pub fn builder<S: Into<String>>(name: S) -> ElementBuilder {
ElementBuilder {
root: Element::new(name.into(), None, Vec::new(), Vec::new()),
root: Element::new(name.into(), None, BTreeMap::new(), Vec::new()),
}
}
@ -144,7 +131,7 @@ impl Element {
Element {
name: name.into(),
namespace: None,
attributes: Vec::new(),
attributes: BTreeMap::new(),
children: Vec::new(),
}
}
@ -162,10 +149,8 @@ impl Element {
/// Returns a reference to the value of the given attribute, if it exists, else `None`.
pub fn attr(&self, name: &str) -> Option<&str> {
for attr in &self.attributes {
if attr.name == name {
return Some(&attr.value);
}
if let Some(value) = self.attributes.get(name) {
return Some(&value)
}
None
}
@ -174,14 +159,14 @@ impl Element {
pub fn set_attr<S: Into<String>, V: IntoAttributeValue>(&mut self, name: S, val: V) {
let name = name.into();
let val = val.into_attribute_value();
for attr in &mut self.attributes {
if attr.name == name {
attr.value = val.expect("removing existing value via set_attr, this is not yet supported (TODO)"); // TODO
return;
}
if let Some(value) = self.attributes.get_mut(&name) {
*value = val.expect("removing existing value via set_attr, this is not yet supported (TODO)"); // TODO
return;
}
if let Some(val) = val {
self.attributes.push(Attribute::new(name, val));
self.attributes.insert(name, val);
}
}
@ -212,13 +197,11 @@ impl Element {
ReaderEvent::StartElement { name, attributes, namespace } => {
let attributes = attributes.into_iter()
.map(|o| {
Attribute::new(
match o.name.prefix {
Some(prefix) => format!("{}:{}", prefix, o.name.local_name),
None => o.name.local_name
},
o.value
)
(match o.name.prefix {
Some(prefix) => format!("{}:{}", prefix, o.name.local_name),
None => o.name.local_name
},
o.value)
})
.collect();
let ns = if let Some(ref prefix) = name.prefix {
@ -247,13 +230,11 @@ impl Element {
ReaderEvent::StartElement { name, attributes, namespace } => {
let attributes = attributes.into_iter()
.map(|o| {
Attribute::new(
match o.name.prefix {
Some(prefix) => format!("{}:{}", prefix, o.name.local_name),
None => o.name.local_name
},
o.value
)
(match o.name.prefix {
Some(prefix) => format!("{}:{}", prefix, o.name.local_name),
None => o.name.local_name
},
o.value)
})
.collect();
let ns = if let Some(ref prefix) = name.prefix {
@ -297,7 +278,7 @@ impl Element {
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(Name::local(&attr.name), &attr.value);
start = start.attr(Name::local(&attr.0), &attr.1);
}
writer.write(start)?;
for child in &self.children {
@ -582,7 +563,7 @@ impl ElementBuilder {
fn test_element_new() {
let elem = Element::new( "name".to_owned()
, Some("namespace".to_owned())
, vec![ Attribute::new("name", "value") ]
, BTreeMap::from_iter(vec![ ("name".to_string(), "value".to_string()) ].into_iter() )
, Vec::new() );
assert_eq!(elem.name(), "name");