markdown_that/plugins/cmark/inline/
autolink.rs

1//! Autolinks
2//!
3//! `<https://example.org>`
4//!
5//! <https://spec.commonmark.org/0.30/#autolinks>
6
7use regex::Regex;
8use std::sync::LazyLock;
9
10use crate::parser::inline::{InlineRule, InlineState, TextSpecial};
11use crate::{MarkdownThat, Node, NodeValue, Renderer};
12
13#[derive(Debug)]
14pub struct Autolink {
15    pub url: String,
16}
17
18impl NodeValue for Autolink {
19    fn render(&self, node: &Node, fmt: &mut dyn Renderer) {
20        let mut attrs = node.attrs.clone();
21        attrs.push(("href", self.url.clone()));
22
23        fmt.open("a", &attrs);
24        fmt.contents(&node.children);
25        fmt.close("a");
26    }
27}
28
29pub fn add(md: &mut MarkdownThat) {
30    md.inline.add_rule::<AutolinkScanner>();
31}
32
33static AUTOLINK_RE: LazyLock<Regex> =
34    LazyLock::new(|| Regex::new(r"^([a-zA-Z][a-zA-Z0-9+.\-]{1,31}):([^<>\x00-\x20]*)$").unwrap());
35
36static EMAIL_RE: LazyLock<Regex> = LazyLock::new(|| {
37    Regex::new(r"^([a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*)$").unwrap()
38});
39
40#[doc(hidden)]
41pub struct AutolinkScanner;
42impl InlineRule for AutolinkScanner {
43    const MARKER: char = '<';
44
45    fn run(state: &mut InlineState) -> Option<(Node, usize)> {
46        let mut chars = state.src[state.pos..state.pos_max].chars();
47        if chars.next().unwrap() != '<' {
48            return None;
49        }
50
51        let mut pos = state.pos + 2;
52
53        loop {
54            match chars.next() {
55                Some('<') | None => return None,
56                Some('>') => break,
57                Some(x) => pos += x.len_utf8(),
58            }
59        }
60
61        let url = &state.src[state.pos + 1..pos - 1];
62        let is_autolink = AUTOLINK_RE.is_match(url);
63        let is_email = EMAIL_RE.is_match(url);
64
65        if !is_autolink && !is_email {
66            return None;
67        }
68
69        let full_url = if is_autolink {
70            state.md.link_formatter.normalize_link(url)
71        } else {
72            state
73                .md
74                .link_formatter
75                .normalize_link(&("mailto:".to_owned() + url))
76        };
77
78        state.md.link_formatter.validate_link(&full_url)?;
79
80        let content = state.md.link_formatter.normalize_link_text(url);
81
82        let mut inner_node = Node::new(TextSpecial {
83            content: content.clone(),
84            markup: content,
85            info: "autolink",
86        });
87        inner_node.srcmap = state.get_map(state.pos + 1, pos - 1);
88
89        let mut node = Node::new(Autolink { url: full_url });
90        node.children.push(inner_node);
91
92        Some((node, pos - state.pos))
93    }
94}