1 | /// Macro that allows you to quickly define a handlebars helper by passing a |
2 | /// name and a closure. |
3 | /// |
4 | /// There are several types of arguments available to closure: |
5 | /// |
6 | /// * Parameters are mapped to closure arguments one by one. Any declared |
7 | /// parameters are required |
8 | /// * Hash are mapped as named arguments and declared in a bracket block. |
9 | /// All named arguments are optional so default value is required. |
10 | /// * An optional `*args` provides a vector of all helper parameters. |
11 | /// * An optional `**kwargs` provides a map of all helper hash. |
12 | /// |
13 | /// # Examples |
14 | /// |
15 | /// ```rust |
16 | /// #[macro_use] extern crate handlebars; |
17 | /// #[macro_use] extern crate serde_json; |
18 | /// |
19 | /// handlebars_helper!(is_above_10: |x: u64| x > 10); |
20 | /// handlebars_helper!(is_above: |x: u64, { compare: u64 = 10 }| x > compare); |
21 | /// |
22 | /// # fn main() { |
23 | /// # |
24 | /// let mut handlebars = handlebars::Handlebars::new(); |
25 | /// handlebars.register_helper("is-above-10" , Box::new(is_above_10)); |
26 | /// handlebars.register_helper("is-above" , Box::new(is_above)); |
27 | /// |
28 | /// let result = handlebars |
29 | /// .render_template("{{#if (is-above-10 12)}}great!{{else}}okay{{/if}}" , &json!({})) |
30 | /// .unwrap(); |
31 | /// assert_eq!(&result, "great!" ); |
32 | /// let result2 = handlebars |
33 | /// .render_template("{{#if (is-above 12 compare=10)}}great!{{else}}okay{{/if}}" , &json!({})) |
34 | /// .unwrap(); |
35 | /// assert_eq!(&result2, "great!" ); |
36 | /// # } |
37 | /// ``` |
38 | |
39 | #[macro_export ] |
40 | macro_rules! handlebars_helper { |
41 | ($struct_name:ident: |$($name:ident: $tpe:tt$(<$($gen:ty),+>)?),* |
42 | $($(,)?{$($hash_name:ident: $hash_tpe:tt=$dft_val:literal),*})? |
43 | $($(,)?*$args:ident)? |
44 | $($(,)?**$kwargs:ident)?| |
45 | $body:expr ) => { |
46 | #[allow(non_camel_case_types)] |
47 | pub struct $struct_name; |
48 | |
49 | impl $crate::HelperDef for $struct_name { |
50 | #[allow(unused_assignments)] |
51 | fn call_inner<'reg: 'rc, 'rc>( |
52 | &self, |
53 | h: &$crate::Helper<'reg, 'rc>, |
54 | r: &'reg $crate::Handlebars<'reg>, |
55 | _: &'rc $crate::Context, |
56 | _: &mut $crate::RenderContext<'reg, 'rc>, |
57 | ) -> std::result::Result<$crate::ScopedJson<'reg, 'rc>, $crate::RenderError> { |
58 | let mut param_idx = 0; |
59 | |
60 | $( |
61 | let $name = h.param(param_idx) |
62 | .and_then(|x| { |
63 | if r.strict_mode() && x.is_value_missing() { |
64 | None |
65 | } else { |
66 | Some(x.value()) |
67 | } |
68 | }) |
69 | .ok_or_else(|| $crate::RenderError::new(&format!( |
70 | "`{}` helper: Couldn't read parameter {}" , |
71 | stringify!($struct_name), stringify!($name), |
72 | ))) |
73 | .and_then(|x| |
74 | handlebars_helper!(@as_json_value x, $tpe$(<$($gen),+>)?) |
75 | .ok_or_else(|| $crate::RenderError::new(&format!( |
76 | "`{}` helper: Couldn't convert parameter {} to type `{}`. \ |
77 | It's {:?} as JSON. Got these params: {:?}" , |
78 | stringify!($struct_name), stringify!($name), stringify!($tpe$(<$($gen),+>)?), |
79 | x, h.params(), |
80 | ))) |
81 | )?; |
82 | param_idx += 1; |
83 | )* |
84 | |
85 | $( |
86 | $( |
87 | let $hash_name = h.hash_get(stringify!($hash_name)) |
88 | .map(|x| x.value()) |
89 | .map(|x| |
90 | handlebars_helper!(@as_json_value x, $hash_tpe) |
91 | .ok_or_else(|| $crate::RenderError::new(&format!( |
92 | "`{}` helper: Couldn't convert hash {} to type `{}`. \ |
93 | It's {:?} as JSON. Got these hash: {:?}" , |
94 | stringify!($struct_name), stringify!($hash_name), stringify!($hash_tpe), |
95 | x, h.hash(), |
96 | ))) |
97 | ) |
98 | .unwrap_or_else(|| Ok($dft_val))?; |
99 | )* |
100 | )? |
101 | |
102 | $(let $args = h.params().iter().map(|x| x.value()).collect::<Vec<&serde_json::Value>>();)? |
103 | $(let $kwargs = h.hash().iter().map(|(k, v)| (k.to_owned(), v.value())).collect::<std::collections::BTreeMap<&str, &serde_json::Value>>();)? |
104 | |
105 | let result = $body; |
106 | Ok($crate::ScopedJson::Derived($crate::JsonValue::from(result))) |
107 | } |
108 | } |
109 | }; |
110 | |
111 | (@as_json_value $x:ident, object) => { $x.as_object() }; |
112 | (@as_json_value $x:ident, array) => { $x.as_array() }; |
113 | (@as_json_value $x:ident, str) => { $x.as_str() }; |
114 | (@as_json_value $x:ident, i64) => { $x.as_i64() }; |
115 | (@as_json_value $x:ident, u64) => { $x.as_u64() }; |
116 | (@as_json_value $x:ident, f64) => { $x.as_f64() }; |
117 | (@as_json_value $x:ident, bool) => { $x.as_bool() }; |
118 | (@as_json_value $x:ident, null) => { $x.as_null() }; |
119 | (@as_json_value $x:ident, Json) => { Some($x) }; |
120 | (@as_json_value $x:ident, $tpe:tt$(<$($gen:ty),+>)?) => { serde_json::from_value::<$tpe$(<$($gen),+>)?>($x.clone()).ok() }; |
121 | } |
122 | |
123 | #[cfg (feature = "no_logging" )] |
124 | #[macro_use ] |
125 | #[doc (hidden)] |
126 | pub mod logging { |
127 | /// This macro is defined if the `logging` feature is set. |
128 | /// |
129 | /// It ignores all logging calls inside the library. |
130 | #[doc (hidden)] |
131 | #[macro_export ] |
132 | macro_rules! debug { |
133 | (target: $target:expr, $($arg:tt)*) => {}; |
134 | ($($arg:tt)*) => {}; |
135 | } |
136 | |
137 | /// This macro is defined if the `logging` feature is not set. |
138 | /// |
139 | /// It ignores all logging calls inside the library. |
140 | #[doc (hidden)] |
141 | #[macro_export ] |
142 | macro_rules! error { |
143 | (target: $target:expr, $($arg:tt)*) => {}; |
144 | ($($arg:tt)*) => {}; |
145 | } |
146 | |
147 | /// This macro is defined if the `logging` feature is not set. |
148 | /// |
149 | /// It ignores all logging calls inside the library. |
150 | #[doc (hidden)] |
151 | #[macro_export ] |
152 | macro_rules! info { |
153 | (target: $target:expr, $($arg:tt)*) => {}; |
154 | ($($arg:tt)*) => {}; |
155 | } |
156 | |
157 | /// This macro is defined if the `logging` feature is not set. |
158 | /// |
159 | /// It ignores all logging calls inside the library. |
160 | #[doc (hidden)] |
161 | #[macro_export ] |
162 | macro_rules! log { |
163 | (target: $target:expr, $($arg:tt)*) => {}; |
164 | ($($arg:tt)*) => {}; |
165 | } |
166 | |
167 | /// This macro is defined if the `logging` feature is not set. |
168 | /// |
169 | /// It ignores all logging calls inside the library. |
170 | #[doc (hidden)] |
171 | #[macro_export ] |
172 | macro_rules! trace { |
173 | (target: $target:expr, $($arg:tt)*) => {}; |
174 | ($($arg:tt)*) => {}; |
175 | } |
176 | |
177 | /// This macro is defined if the `logging` feature is not set. |
178 | /// |
179 | /// It ignores all logging calls inside the library. |
180 | #[doc (hidden)] |
181 | #[macro_export ] |
182 | macro_rules! warn { |
183 | (target: $target:expr, $($arg:tt)*) => {}; |
184 | ($($arg:tt)*) => {}; |
185 | } |
186 | } |
187 | |