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handlebars/helpers/
helper_log.rs

1#[cfg(not(feature = "no_logging"))]
2use crate::RenderErrorReason;
3use crate::context::Context;
4use crate::helpers::{HelperDef, HelperResult};
5#[cfg(not(feature = "no_logging"))]
6use crate::json::value::JsonRender;
7use crate::output::Output;
8use crate::registry::Registry;
9use crate::render::{Helper, RenderContext};
10#[cfg(not(feature = "no_logging"))]
11use log::Level;
12#[cfg(not(feature = "no_logging"))]
13use std::str::FromStr;
14
15#[derive(Clone, Copy)]
16pub struct LogHelper;
17
18#[cfg(not(feature = "no_logging"))]
19impl HelperDef for LogHelper {
20    fn call<'reg: 'rc, 'rc>(
21        &self,
22        h: &Helper<'rc>,
23        _: &'reg Registry<'reg>,
24        _: &'rc Context,
25        _: &mut RenderContext<'reg, 'rc>,
26        _: &mut dyn Output,
27    ) -> HelperResult {
28        let param_to_log = h
29            .params()
30            .iter()
31            .map(|p| {
32                if let Some(relative_path) = p.relative_path() {
33                    format!("{}: {}", &relative_path, p.value().render())
34                } else {
35                    p.value().render()
36                }
37            })
38            .collect::<Vec<String>>()
39            .join(", ");
40
41        let level = h
42            .hash_get("level")
43            .and_then(|v| v.value().as_str())
44            .unwrap_or("info");
45
46        if let Ok(log_level) = Level::from_str(level) {
47            log!(log_level, "{}", param_to_log);
48        } else {
49            return Err(RenderErrorReason::InvalidLoggingLevel(level.to_string()).into());
50        }
51        Ok(())
52    }
53}
54
55#[cfg(feature = "no_logging")]
56impl HelperDef for LogHelper {
57    fn call<'reg: 'rc, 'rc>(
58        &self,
59        _: &Helper<'rc>,
60        _: &Registry<'reg>,
61        _: &Context,
62        _: &mut RenderContext<'reg, 'rc>,
63        _: &mut dyn Output,
64    ) -> HelperResult {
65        Ok(())
66    }
67}
68
69pub static LOG_HELPER: LogHelper = LogHelper;
70
71#[cfg(test)]
72mod test {
73    use crate::registry::Registry;
74
75    #[test]
76    #[cfg(not(feature = "no_logging"))]
77    fn test_log_helper() {
78        let mut handlebars = Registry::new();
79        assert!(
80            handlebars
81                .register_template_string("t0", "{{log this level=\"warn\"}}")
82                .is_ok()
83        );
84        assert!(
85            handlebars
86                .register_template_string("t1", "{{log this level=\"hello\"}}")
87                .is_ok()
88        );
89        assert!(
90            handlebars
91                .register_template_string("t2", "{{log this}}")
92                .is_ok()
93        );
94
95        let r0 = handlebars.render("t0", &true);
96        assert!(r0.is_ok());
97
98        let r1 = handlebars.render("t1", &true);
99        assert!(r1.is_err());
100
101        let r2 = handlebars.render("t2", &true);
102        assert!(r2.is_ok());
103    }
104
105    #[test]
106    #[cfg(feature = "no_logging")]
107    fn test_log_helper() {
108        let mut handlebars = Registry::new();
109        assert!(
110            handlebars
111                .register_template_string("t0", "{{log this level=\"warn\"}}")
112                .is_ok()
113        );
114        assert!(
115            handlebars
116                .register_template_string("t1", "{{log this level=\"hello\"}}")
117                .is_ok()
118        );
119        assert!(
120            handlebars
121                .register_template_string("t2", "{{log this}}")
122                .is_ok()
123        );
124
125        let r0 = handlebars.render("t0", &true);
126        assert!(r0.is_ok());
127
128        let r1 = handlebars.render("t1", &true);
129        assert!(r1.is_ok());
130
131        let r2 = handlebars.render("t2", &true);
132        assert!(r2.is_ok());
133    }
134}