hello.html

<label>{{ todo.subject|linkify|safe }}</label>

output.txt

[Running 'cargo run']
   Compiling homepage v0.1.0 (file:///C:/Users/kevin/src/homepage)
error[E0597]: borrowed value does not live long enough
  --> src\view.rs:27:10
   |
27 | #[derive(Template)]
   |          ^^^^^^^-
   |          |      |
   |          |      temporary value dropped here while still borrowed
   |          temporary value does not live long enough
   |
   = note: values in a scope are dropped in the opposite order they are created
   = note: consider using a `let` binding to increase its lifetime

error: aborting due to previous error

For more information about this error, try `rustc --explain E0597`.
error: Could not compile `homepage`.

view.rs

use askama::Template;

mod filters {
    pub fn linkify(s: &str) -> ::askama::Result<String> {
        let mut finder = ::linkify::LinkFinder::new();
        finder.kinds(&[::linkify::LinkKind::Url]);
        let mut last = 0;
        let mut result = String::new();
        for link in finder.links(&s) {
            result.push_str(&s[last .. link.start()]);
            result.push_str(&format!("<a href=\"{}\">{}</a>", link.as_str(), link.as_str()));
            last = link.end();
        }
        if last == 0 {
            result = s.to_string();
        } else {
            result.push_str(&s[last ..]);
        }
        Ok(result)
    }
}

#[derive(Template)]
#[template(path = "hello.html")]
struct HelloTemplate<'a> {
/* .. */
}