aboutsummaryrefslogtreecommitdiff
path: root/src/attr.rs
blob: d062a84573d0adc84c43d08964282f36d19c2af4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
//! Types for HTML attributes.

use std::collections::{btree_map, BTreeMap};
use std::iter::FromIterator;
use std::ops::{Index, Range};

use crate::offset::Offset;

/// A map of HTML attributes.
///
/// Does not preserve the order of attributes.
/// Iterating always yields attributes in order by name.
///
/// # Example
///
/// ```
/// # use html5tokenizer::attr::AttributeMap;
/// let attrs: AttributeMap<()> = vec![("href".into(), "http://example.com".into())]
///     .into_iter()
///     .collect();
/// assert_eq!(&attrs["href"], "http://example.com");
/// ```
#[derive(Debug, Default, PartialEq, Eq)]
pub struct AttributeMap<O> {
    pub(crate) inner: BTreeMap<String, AttrInternal<O>>,
}

/// The value type internally used by the [`AttributeMap`].
/// Not part of the public API.
#[derive(Debug, Eq, PartialEq)]
pub(crate) struct AttrInternal<O> {
    pub value: String,
    /// The start offset of the attribute name.
    pub name_offset: O,
    /// The start offset of the attribute value.
    pub value_offset: O,
    pub value_syntax: Option<AttrValueSyntax>,
}

/// The syntax of the attribute value.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum AttrValueSyntax {
    /// An unquoted attribute value, e.g. `id=foo`.
    Unquoted,
    /// A single-quoted attribute value, e.g. `id='foo'`.
    SingleQuoted,
    /// A double-quoted attribute value, e.g. `id="foo"`.
    DoubleQuoted,
}

/// An HTML attribute borrowed from an [`AttributeMap`].
#[derive(Debug, Eq, PartialEq)]
pub struct Attribute<'a, O> {
    name: &'a str,
    map_val: &'a AttrInternal<O>,
}

/// An owned HTML attribute.
#[derive(Debug, PartialEq, Eq)]
pub struct AttributeOwned<O> {
    /// The attribute name.
    pub name: String,
    /// The attribute value.
    pub value: String,
    /// The start offset of the attribute name.
    pub name_offset: O,
    /// The start offset of the attribute value.
    pub value_offset: O, // TODO: wrap this in an Option once we can recognize the empty attribute syntax
    /// The syntax of the attribute value.
    /// `None` indicates the empty attribute syntax (e.g. `disabled` in `<input disabled>`).
    pub value_syntax: Option<AttrValueSyntax>,
}

impl<O> AttributeMap<O> {
    /// Returns the attribute with the given name.
    pub fn get(&self, name: &str) -> Option<Attribute<O>> {
        self.inner
            .get_key_value(name)
            .map(|(name, map_val)| Attribute { name, map_val })
    }
}

impl<'a, O: Offset> Attribute<'a, O> {
    /// Returns the attribute name.
    pub fn name(&self) -> &'a str {
        self.name
    }

    /// Returns the attribute value.
    pub fn value(&self) -> &'a str {
        &self.map_val.value
    }

    /// Calculates the span of the attribute name and returns it.
    pub fn name_span(&self) -> Range<O> {
        self.map_val.name_offset..self.map_val.name_offset + self.name.len()
    }

    /// Calculates the span of the attribute value and returns it.
    pub fn value_span(&self) -> Range<O> {
        self.map_val.value_offset..self.map_val.value_offset + self.map_val.value.len()
    }

    /// Returns the attribute value syntax in case the value is explicitly defined.
    ///
    /// Returns `None` for attributes using the empty attribute syntax (e.g. `disabled` in `<input disabled>`).
    pub fn value_syntax(&self) -> Option<AttrValueSyntax> {
        self.map_val.value_syntax
    }
}

// We cannot impl Index<Output=Attribute> because Index::index returns a reference of
// the Output type (and you cannot return a value referencing a temporary value).
impl<O> Index<&str> for AttributeMap<O> {
    type Output = str;

    fn index(&self, name: &str) -> &Self::Output {
        &self.inner[name].value
    }
}

impl<O> IntoIterator for AttributeMap<O> {
    type Item = AttributeOwned<O>;

    type IntoIter = AttrIntoIter<O>;

    fn into_iter(self) -> Self::IntoIter {
        AttrIntoIter(self.inner.into_iter())
    }
}

/// A consuming iterator over the attributes of an [`AttributeMap`].
pub struct AttrIntoIter<O>(btree_map::IntoIter<String, AttrInternal<O>>);

impl<O> Iterator for AttrIntoIter<O> {
    type Item = AttributeOwned<O>;

    fn next(&mut self) -> Option<Self::Item> {
        let (name, map_val) = self.0.next()?;
        Some(AttributeOwned {
            name,
            value: map_val.value,
            name_offset: map_val.name_offset,
            value_offset: map_val.value_offset,
            value_syntax: map_val.value_syntax,
        })
    }
}

impl<'a, O> IntoIterator for &'a AttributeMap<O> {
    type Item = Attribute<'a, O>;

    type IntoIter = AttrIter<'a, O>;

    fn into_iter(self) -> Self::IntoIter {
        AttrIter(self.inner.iter())
    }
}

/// A borrowed iterator over the attributes of an [`AttributeMap`].
pub struct AttrIter<'a, S>(btree_map::Iter<'a, String, AttrInternal<S>>);

impl<'a, S> Iterator for AttrIter<'a, S> {
    type Item = Attribute<'a, S>;

    fn next(&mut self) -> Option<Self::Item> {
        let (name, map_val) = self.0.next()?;
        Some(Attribute { name, map_val })
    }
}

impl<O: Default> FromIterator<(String, String)> for AttributeMap<O> {
    fn from_iter<T: IntoIterator<Item = (String, String)>>(iter: T) -> Self {
        Self {
            inner: iter
                .into_iter()
                .map(|(name, value)| {
                    (
                        name,
                        AttrInternal {
                            value,
                            name_offset: O::default(),
                            value_offset: O::default(),
                            value_syntax: Some(AttrValueSyntax::DoubleQuoted),
                        },
                    )
                })
                .collect(),
        }
    }
}

impl<O: Offset> AttrInternal<O> {
    pub(crate) fn name_span(&self, name_len: usize) -> Range<O> {
        self.name_offset..self.name_offset + name_len
    }
}