acmed/acmed/src/template.rs

use acme_common::error::Error;
use serde::Serialize;
use serde_json::Value;
use tinytemplate::TinyTemplate;

macro_rules! default_format {
	($value: ident, $output: ident) => {{
		$output.push_str(&$value.to_string());
		Ok(())
	}};
}

fn formatter_rev_labels(value: &Value, output: &mut String) -> tinytemplate::error::Result<()> {
	match value {
		Value::Null => Ok(()),
		Value::Bool(v) => default_format!(v, output),
		Value::Number(v) => default_format!(v, output),
		Value::String(v) => {
			let s = v.rsplit('.').collect::<Vec<&str>>().join(".");
			output.push_str(&s);
			Ok(())
		}
		_ => Ok(()),
	}
}

pub fn render_template<T>(template: &str, data: &T) -> Result<String, Error>
where
	T: Serialize,
{
	let mut reg = TinyTemplate::new();
	reg.add_formatter("rev_labels", formatter_rev_labels);
	reg.add_template("reg", template)?;
	Ok(reg.render("reg", data)?)
}

#[cfg(test)]
mod tests {
	use super::render_template;
	use serde::Serialize;

	#[derive(Serialize)]
	struct TplTest {
		foo: String,
		bar: u64,
	}

	#[test]
	fn test_basic_template() {
		let c = TplTest {
			foo: String::from("test"),
			bar: 42,
		};
		let tpl = "This is { foo } { bar -} !";
		let rendered = render_template(tpl, &c);
		assert!(rendered.is_ok());
		let rendered = rendered.unwrap();
		assert_eq!(rendered, "This is test 42!");
	}

	#[test]
	fn test_formatter_rev_labels() {
		let c = TplTest {
			foo: String::from("mx1.example.org"),
			bar: 42,
		};
		let tpl = "{ foo } - { foo | rev_labels }";
		let rendered = render_template(tpl, &c);
		assert!(rendered.is_ok());
		let rendered = rendered.unwrap();
		assert_eq!(rendered, "mx1.example.org - org.example.mx1");
	}
}