feed-rs 3.0.0

A feed parser that handles Atom, RSS 2.0, RSS 1.0, RSS 0.x and JSON Feed
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

use std::io::BufRead;

use crate::model::{Content, Entry, Feed, FeedType, Image, Link, Person, Text};
use crate::parser::util::if_some_then;
use crate::parser::{ParseFeedResult, Parser, common};
use crate::xml::{Element, NS};

#[cfg(test)]
mod tests;

/// Parses an RSS 1.0 feed into our model
pub(crate) fn parse<R: BufRead>(parser: &Parser, root: Element<R>) -> ParseFeedResult<Feed> {
    let mut feed = Feed::new(FeedType::RSS1);

    for child in root.children() {
        let child = child?;
        match child.ns_and_tag() {
            (NS::RSS, "channel") => handle_channel(parser, &mut feed, child)?,

            (NS::RSS, "image") => feed.logo = handle_image(child)?,

            (NS::RSS, "item") => if_some_then(handle_item(parser, child)?, |entry| feed.entries.push(entry)),

            // Nothing required for unknown elements
            _ => {}
        }
    }

    Ok(feed)
}

// Handles the <channel> element
fn handle_channel<R: BufRead>(parser: &Parser, feed: &mut Feed, channel: Element<R>) -> ParseFeedResult<()> {
    for child in channel.children() {
        let child = child?;
        match child.ns_and_tag() {
            (NS::RSS, "title") => feed.title = common::handle_text(child),

            (NS::RSS, "link") => if_some_then(common::handle_link(None, child), |link| feed.links.push(link)),

            (NS::RSS, "description") => feed.description = common::handle_text(child),

            (NS::DublinCore, "creator") => if_some_then(child.child_as_text(), |name| feed.authors.push(Person::parse(&name).role("creator"))),

            (NS::DublinCore, "date") => feed.published = common::handle_timestamp(parser, child),

            (NS::DublinCore, "language") => feed.language = child.child_as_text(),

            (NS::DublinCore, "rights") => feed.rights = common::handle_text(child),

            // Nothing required for unknown elements
            _ => {}
        }
    }

    Ok(())
}

// Handles <image>
fn handle_image<R: BufRead>(element: Element<R>) -> ParseFeedResult<Option<Image>> {
    let mut image = Image::new("".to_owned());

    for child in element.children() {
        let child = child?;
        match child.ns_and_tag() {
            (NS::RSS, "url") => if_some_then(child.child_as_text(), |url| image.uri = url),

            (NS::RSS, "title") => image.title = child.child_as_text(),

            (NS::RSS, "link") => if_some_then(child.child_as_text(), |uri| image.link = Some(Link::new(uri, element.xml_base.as_ref()))),

            // Nothing required for unknown elements
            _ => {}
        }
    }

    // If we don't have a URI there is no point returning an image
    Ok(if !image.uri.is_empty() { Some(image) } else { None })
}

// Handles <item>
fn handle_item<R: BufRead>(parser: &Parser, element: Element<R>) -> ParseFeedResult<Option<Entry>> {
    let mut entry = Entry::default();

    // Per https://www.w3.org/wiki/RssContent:
    //   How to encode content in a RSS 1.0 feed is an unsolved problem, many persons have made different problems and there's no consensus for a definitive solution.
    // But we see it in real feeds, so might as well add it in the same manner as RSS2.0 best practice
    let mut content_encoded: Option<Text> = None;

    for child in element.children() {
        let child = child?;
        match child.ns_and_tag() {
            (NS::RSS, "title") => entry.title = common::handle_text(child),

            (NS::RSS, "link") => if_some_then(common::handle_link(None, child), |link| entry.links.push(link)),

            (NS::RSS, "description") => entry.summary = common::handle_text(child),

            (NS::Content, "encoded") => content_encoded = common::handle_encoded(child)?,

            (NS::DublinCore, "creator") => if_some_then(child.child_as_text(), |name| entry.authors.push(Person::parse(&name).role("creator"))),

            (NS::DublinCore, "date") => entry.published = common::handle_timestamp(parser, child),

            (NS::DublinCore, "description") if entry.summary.is_none() => entry.summary = common::handle_text(child),

            (NS::DublinCore, "rights") => entry.rights = common::handle_text(child),

            // Nothing required for unknown elements
            _ => {}
        }
    }

    // Use content_encoded if we didn't find an enclosure above
    if entry.content.is_none() {
        if let Some(ce) = content_encoded {
            entry.content = Some(Content {
                body: Some(ce.content),
                content_type: ce.content_type,
                length: None,
                src: ce.src.map(|s| Link::new(s, element.xml_base.as_ref())),
            });
        }
    }

    // If we found at least 1 link
    Ok(if !entry.links.is_empty() {
        Some(entry)
    } else {
        // No point returning anything if we are missing a destination
        None
    })
}