typst/library/src/meta/link.rs
2022-12-20 15:55:15 +01:00

108 lines
3.2 KiB
Rust

use crate::prelude::*;
use crate::text::TextNode;
/// Link to a URL or another location in the document.
///
/// The link function makes its positional `body` argument clickable and links
/// it to the destination specified by the `dest` argument.
///
/// # Example
/// ```
/// #show link: underline
///
/// #link("https://example.com") \
/// #link("https://example.com")[
/// See example.com
/// ]
/// ```
///
/// # Parameters
/// - dest: Destination (positional, required)
/// The destination the link points to.
///
/// - To link to web pages, `dest` should be a valid URL string. If the URL is
/// in the `mailto:` or `tel:` scheme and the `body` parameter is omitted,
/// the email address or phone number will be the link's body, without the
/// scheme.
///
/// - To link to another part of the document, `dest` must contain a
/// dictionary with a `page` key of type `integer` and `x` and `y`
/// coordinates of type `length`. Pages are counted from one, and the
/// coordinates are relative to the page's top left corner.
///
/// # Example
/// ```
/// #link("mailto:hello@typst.app") \
/// #link((page: 1, x: 0pt, y: 0pt))[
/// Go to top
/// ]
/// ```
///
/// - body: Content (positional)
///
/// The content that should become a link. If `dest` is an URL string, the
/// parameter can be omitted. In this case, the URL will be shown as the link.
///
/// # Tags
/// - meta
#[func]
#[capable(Show, Finalize)]
#[derive(Debug, Hash)]
pub struct LinkNode {
/// The destination the link points to.
pub dest: Destination,
/// How the link is represented.
pub body: Content,
}
impl LinkNode {
/// Create a link node from a URL with its bare text.
pub fn from_url(url: EcoString) -> Self {
let mut text = url.as_str();
for prefix in ["mailto:", "tel:"] {
text = text.trim_start_matches(prefix);
}
let shorter = text.len() < url.len();
let body = TextNode::packed(if shorter { text.into() } else { url.clone() });
Self { dest: Destination::Url(url), body }
}
}
#[node]
impl LinkNode {
fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
let dest = args.expect::<Destination>("destination")?;
Ok(match dest {
Destination::Url(url) => match args.eat()? {
Some(body) => Self { dest: Destination::Url(url), body },
None => Self::from_url(url),
},
Destination::Internal(_) => Self { dest, body: args.expect("body")? },
}
.pack())
}
fn field(&self, name: &str) -> Option<Value> {
match name {
"url" => Some(match &self.dest {
Destination::Url(url) => Value::Str(url.clone().into()),
Destination::Internal(loc) => Value::Dict(loc.encode()),
}),
"body" => Some(Value::Content(self.body.clone())),
_ => None,
}
}
}
impl Show for LinkNode {
fn show(&self, _: &mut Vt, _: &Content, _: StyleChain) -> SourceResult<Content> {
Ok(self.body.clone())
}
}
impl Finalize for LinkNode {
fn finalize(&self, realized: Content) -> Content {
realized.styled(Meta::DATA, vec![Meta::Link(self.dest.clone())])
}
}