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
|
use std::error::Error;
use handlebars::{handlebars_helper, Handlebars, JsonRender};
use serde_json::{json, Value};
use time::format_description::parse;
use time::OffsetDateTime;
// define a helper using helper
// a date format helper accept an `OffsetDateTime` as parameter
handlebars_helper!(date: |dt: OffsetDateTime| dt.format(&parse("[year]-[month]-[day]").unwrap()).unwrap());
// a helper returns number of provided parameters
handlebars_helper!(nargs: |*args| args.len());
// a helper joins all values, using both hash and parameters
handlebars_helper!(join: |{sep:str=","}, *args|
args.iter().map(|a| a.render()).collect::<Vec<String>>().join(sep)
);
handlebars_helper!(isdefined: |v: Value| !v.is_null());
// a helper provides format
handlebars_helper!(date2: |dt: OffsetDateTime, {fmt:str = "[year]-[month]-[day]"}|
dt.format(&parse(fmt).unwrap()).unwrap()
);
fn main() -> Result<(), Box<dyn Error>> {
// create the handlebars registry
let mut handlebars = Handlebars::new();
handlebars.register_helper("date", Box::new(date));
handlebars.register_helper("date2", Box::new(date2));
handlebars.register_helper("nargs", Box::new(nargs));
handlebars.register_helper("join", Box::new(join));
handlebars.register_helper("isdefined", Box::new(isdefined));
let data = OffsetDateTime::now_utc();
println!("{}", handlebars.render_template("{{date this}}", &data)?);
println!("{}", handlebars.render_template("{{date2 this}}", &data)?);
println!(
"{}",
handlebars.render_template("{{date2 this fmt=\"[day]/[month]/[year]\"}}", &data)?
);
println!("{}", handlebars.render_template("{{nargs 1 2 3 4}}", &())?);
println!(
"{}",
handlebars.render_template("{{join 1 2 3 4 sep=\"|\" }}", &())?
);
println!(
"{}",
handlebars.render_template(
r#"{{isdefined a}} {{isdefined b}}
{{#if (isdefined a)}}a{{/if}} {{#if (isdefined b)}}b{{/if}}"#,
&json!({"a": 1})
)?
);
Ok(())
}
|
