ux-webmachine 0.1.0

Port of the Ruby Webmachine library to Rust
Documentation 
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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237

//! The `content_negotiation` module deals with handling media types, languages, charsets and
//! encodings as per [https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html][1].
//! 
//! [1]: https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html


use itertools::Itertools;
use std::cmp::Ordering;

use crate::{context::Request, headers::HeaderValue, Resource};

mod charset;
pub use self::charset::*;

mod encoding;
pub use self::encoding::*;

mod medialanguage;
pub use self::medialanguage::*;

mod mediatype;
pub use self::mediatype::*;

/// Sorts the list of media types by their weights
pub fn sort_media_types(media_types: &Vec<HeaderValue>) -> Vec<HeaderValue> {
    media_types
        .into_iter()
        .cloned()
        .sorted_by(|a, b| {
            let media_a = a.as_media_type().weight();
            let media_b = b.as_media_type().weight();
            let order = media_a
                .0
                .partial_cmp(&media_b.0)
                .unwrap_or(Ordering::Greater);
            if order == Ordering::Equal {
                Ord::cmp(&media_a.1, &media_b.1)
            } else {
                order.reverse()
            }
        })
        .collect()
}

/// Determines if the media types produced by the resource matches the acceptable media types
/// provided by the client. Returns the match if there is one.
pub fn matching_content_type(
    resource: &Resource,
    request: &Request,
) -> Option<String> {
    if request.has_accept_header() {
        let acceptable_media_types = sort_media_types(&request.accept());
        resource
            .produces
            .iter()
            .cloned()
            .cartesian_product(acceptable_media_types.iter())
            .map(|(produced, acceptable)| {
                let acceptable_media_type = acceptable.as_media_type();
                let produced_media_type = MediaType::parse_string(produced);
                (
                    produced_media_type.clone(),
                    acceptable_media_type.clone(),
                    produced_media_type.matches(&acceptable_media_type),
                )
            })
            .sorted_by(|a, b| Ord::cmp(&a.2, &b.2))
            .filter(|val| val.2 != MediaTypeMatch::None)
            .next()
            .map(|result| result.0.to_string())
    } else {
        resource.produces.first().map(|s| s.to_string())
    }
}

/// Sorts the list of media types by weighting
pub fn sort_media_languages(media_languages: &Vec<HeaderValue>) -> Vec<MediaLanguage> {
    media_languages
        .iter()
        .cloned()
        .map(|lang| lang.as_media_language())
        .filter(|lang| lang.weight > 0.0)
        .sorted_by(|a, b| {
            let weight_a = a.weight;
            let weight_b = b.weight;
            weight_b.partial_cmp(&weight_a).unwrap_or(Ordering::Greater)
        })
        .collect()
}

/// Determines if the languages produced by the resource matches the acceptable languages
/// provided by the client. Returns the match if there is one.
pub fn matching_language(
    resource: &Resource,
    request: &Request,
) -> Option<String> {
    if request.has_accept_language_header() && !request.accept_language().is_empty() {
        let acceptable_languages = sort_media_languages(&request.accept_language());
        if resource.languages_provided.is_empty() {
            acceptable_languages.first().map(|lang| lang.to_string())
        } else {
            acceptable_languages
                .iter()
                .cartesian_product(resource.languages_provided.iter())
                .map(|(acceptable_language, produced_language)| {
                    let produced_language = MediaLanguage::parse_string(produced_language);
                    (
                        produced_language.clone(),
                        produced_language.matches(&acceptable_language),
                    )
                })
                .find(|val| val.1)
                .map(|result| result.0.to_string())
        }
    } else if resource.languages_provided.is_empty() {
        Some("*".to_string())
    } else {
        resource.languages_provided.first().map(|s| s.to_string())
    }
}

/// Sorts the list of charsets by weighting as per [https://tools.ietf.org/html/rfc2616#section-14.2][1].
/// Note that ISO-8859-1 is added as a default with a weighting of 1 if not all ready supplied.
/// 
/// [1]: https://tools.ietf.org/html/rfc2616#section-14.2
pub fn sort_media_charsets(charsets: &Vec<HeaderValue>) -> Vec<Charset> {
    let mut charsets = charsets.clone();
    if charsets
        .iter()
        .find(|cs| cs.value == "*" || cs.value.to_uppercase() == "ISO-8859-1")
        .is_none()
    {
        charsets.push(h!("ISO-8859-1"));
    }
    charsets
        .into_iter()
        .map(|cs| cs.as_charset())
        .filter(|cs| cs.weight > 0.0)
        .sorted_by(|a, b| {
            let weight_a = a.weight;
            let weight_b = b.weight;
            weight_b.partial_cmp(&weight_a).unwrap_or(Ordering::Greater)
        })
        .collect()
}

/// Determines if the charsets produced by the resource matches the acceptable charsets
/// provided by the client. Returns the match if there is one.
pub fn matching_charset(
    resource: &Resource,
    request: &Request,
) -> Option<String> {
    if request.has_accept_charset_header() && !request.accept_charset().is_empty() {
        let acceptable_charsets = sort_media_charsets(&request.accept_charset());
        if resource.charsets_provided.is_empty() {
            acceptable_charsets.first().map(|cs| cs.to_string())
        } else {
            acceptable_charsets
                .iter()
                .cartesian_product(resource.charsets_provided.iter())
                .map(|(acceptable_charset, provided_charset)| {
                    let provided_charset = Charset::parse_string(provided_charset);
                    (
                        provided_charset.clone(),
                        provided_charset.matches(&acceptable_charset),
                    )
                })
                .find(|val| val.1)
                .map(|result| result.0.to_string())
        }
    } else if resource.charsets_provided.is_empty() {
        Some("ISO-8859-1".to_string())
    } else {
        resource.charsets_provided.first().map(|s| s.to_string())
    }
}

/// Sorts the list of encodings by weighting as per [https://tools.ietf.org/html/rfc2616#section-14.3][1].
/// Note that identity encoding is awlays added with a weight of 1 if not already present.
/// 
/// [1]: https://tools.ietf.org/html/rfc2616#section-14.3
pub fn sort_encodings(encodings: &Vec<HeaderValue>) -> Vec<Encoding> {
    let mut encodings = encodings.clone();
    if encodings
        .iter()
        .find(|e| e.value == "*" || e.value.to_lowercase() == "identity")
        .is_none()
    {
        encodings.push(h!("identity"));
    }
    encodings
        .into_iter()
        .map(|encoding| encoding.as_encoding())
        .filter(|encoding| encoding.weight > 0.0)
        .sorted_by(|a, b| {
            let weight_a = a.weight;
            let weight_b = b.weight;
            weight_b.partial_cmp(&weight_a).unwrap_or(Ordering::Greater)
        })
        .collect()
}

/// Determines if the encodings supported by the resource matches the acceptable encodings
/// provided by the client. Returns the match if there is one.
pub fn matching_encoding(
    resource: &Resource,
    request: &Request,
) -> Option<String> {
    let identity = Encoding::parse_string("identity");
    if request.has_accept_encoding_header() {
        let acceptable_encodings = sort_encodings(&request.accept_encoding());
        if resource.encodings_provided.is_empty() {
            if acceptable_encodings.contains(&identity) {
                Some("identity".to_string())
            } else {
                None
            }
        } else {
            acceptable_encodings
                .iter()
                .cartesian_product(resource.encodings_provided.iter())
                .map(|(acceptable_encoding, provided_encoding)| {
                    let provided_encoding = Encoding::parse_string(provided_encoding);
                    (
                        provided_encoding.clone(),
                        provided_encoding.matches(&acceptable_encoding),
                    )
                })
                .find(|val| val.1)
                .map(|result| result.0.to_string())
        }
    } else if resource.encodings_provided.is_empty() {
        Some("identity".to_string())
    } else {
        resource.encodings_provided.first().map(|s| s.to_string())
    }
}