1//! A module which exports a few traits for converting types to elements and attributes.
2
3use element::{Element, ElementBuilder};
4
5/// A struct which is used for emitting `Element`s and text nodes into an `Element` without
6/// exposing more functionality than necessary.
7pub struct ElementEmitter<'a>(&'a mut Element);
8
9impl<'a> ElementEmitter<'a> {
10 /// Creates a new `ElementEmitter`.
11 pub fn new(root: &'a mut Element) -> ElementEmitter<'a> {
12 ElementEmitter(root)
13 }
14
15 /// Appends an `Element` to the target.
16 pub fn append_child(&mut self, element: Element) {
17 self.0.append_child(element);
18 }
19
20 /// Appends a text node to the target.
21 pub fn append_text_node(&mut self, text: String) {
22 self.0.append_text_node(text);
23 }
24}
25
26/// A trait for types which can be converted to one or multiple `Element`s.
27pub trait IntoElements {
28 /// Emits this as a sequence of text nodes and `Element`s.
29 fn into_elements(self, emitter: &mut ElementEmitter);
30}
31
32impl<T: IntoElements> IntoElements for Vec<T> {
33 fn into_elements(self, emitter: &mut ElementEmitter) {
34 for elem in self {
35 elem.into_elements(emitter);
36 }
37 }
38}
39
40impl<'a, T: IntoElements + Clone> IntoElements for &'a [T] {
41 fn into_elements(self, emitter: &mut ElementEmitter) {
42 self.to_vec().into_elements(emitter);
43 }
44}
45
46impl<T: IntoElements> IntoElements for Option<T> {
47 fn into_elements(self, emitter: &mut ElementEmitter) {
48 match self {
49 Some(e) => e.into_elements(emitter),
50 None => (),
51 }
52 }
53}
54
55impl IntoElements for Element {
56 fn into_elements(self, emitter: &mut ElementEmitter) {
57 emitter.append_child(self);
58 }
59}
60
61impl IntoElements for ElementBuilder {
62 fn into_elements(self, emitter: &mut ElementEmitter) {
63 emitter.append_child(self.build());
64 }
65}
66
67impl IntoElements for String {
68 fn into_elements(self, emitter: &mut ElementEmitter) {
69 emitter.append_text_node(self);
70 }
71}
72
73impl<'a> IntoElements for &'a str {
74 fn into_elements(self, emitter: &mut ElementEmitter) {
75 emitter.append_text_node(self.to_owned());
76 }
77}
78
79/// A trait for types which can be converted to an attribute value.
80pub trait IntoAttributeValue {
81 /// Turns this into an attribute string, or None if it shouldn't be added.
82 fn into_attribute_value(self) -> Option<String>;
83}
84
85impl IntoAttributeValue for String {
86 fn into_attribute_value(self) -> Option<String> {
87 Some(self.clone())
88 }
89}
90
91impl<'a> IntoAttributeValue for &'a str {
92 fn into_attribute_value(self) -> Option<String> {
93 Some((*self).to_owned())
94 }
95}
96
97impl<T: IntoAttributeValue> IntoAttributeValue for Option<T> {
98 fn into_attribute_value(self) -> Option<String> {
99 self.and_then(|t| t.into_attribute_value())
100 }
101}