napi_h/js_values/
function.rs

1use std::ptr;
2
3use super::Value;
4#[cfg(feature = "napi4")]
5use crate::{
6  bindgen_runtime::ToNapiValue,
7  threadsafe_function::{ThreadSafeCallContext, ThreadsafeFunction},
8};
9use crate::{bindgen_runtime::TypeName, JsString};
10use crate::{check_pending_exception, ValueType};
11use crate::{sys, Env, Error, JsObject, JsUnknown, NapiRaw, NapiValue, Result, Status};
12
13pub struct JsFunction(pub(crate) Value);
14
15impl TypeName for JsFunction {
16  fn type_name() -> &'static str {
17    "Function"
18  }
19
20  fn value_type() -> crate::ValueType {
21    ValueType::Function
22  }
23}
24
25/// See [Working with JavaScript Functions](https://nodejs.org/api/n-api.html#n_api_working_with_javascript_functions).
26///
27/// Example:
28/// ```
29/// use napi::{JsFunction, CallContext, JsNull, Result};
30///
31/// #[js_function(1)]
32/// pub fn call_function(ctx: CallContext) -> Result<JsNull> {
33///     let js_func = ctx.get::<JsFunction>(0)?;
34///     let js_string = ctx.env.create_string("hello".as_ref())?.into_unknown()?;
35///     js_func.call(None, &[js_string])?;
36///     Ok(ctx.env.get_null()?)
37/// }
38/// ```
39impl JsFunction {
40  /// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
41  pub fn call<V>(&self, this: Option<&JsObject>, args: &[V]) -> Result<JsUnknown>
42  where
43    V: NapiRaw,
44  {
45    let raw_this = this
46      .map(|v| unsafe { v.raw() })
47      .or_else(|| {
48        unsafe { Env::from_raw(self.0.env) }
49          .get_undefined()
50          .ok()
51          .map(|u| unsafe { u.raw() })
52      })
53      .ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
54    let raw_args = args
55      .iter()
56      .map(|arg| unsafe { arg.raw() })
57      .collect::<Vec<sys::napi_value>>();
58    let mut return_value = ptr::null_mut();
59    check_pending_exception!(self.0.env, unsafe {
60      sys::napi_call_function(
61        self.0.env,
62        raw_this,
63        self.0.value,
64        args.len(),
65        raw_args.as_ptr(),
66        &mut return_value,
67      )
68    })?;
69
70    unsafe { JsUnknown::from_raw(self.0.env, return_value) }
71  }
72
73  /// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
74  /// The same with `call`, but without arguments
75  pub fn call_without_args(&self, this: Option<&JsObject>) -> Result<JsUnknown> {
76    let raw_this = this
77      .map(|v| unsafe { v.raw() })
78      .or_else(|| {
79        unsafe { Env::from_raw(self.0.env) }
80          .get_undefined()
81          .ok()
82          .map(|u| unsafe { u.raw() })
83      })
84      .ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
85    let mut return_value = ptr::null_mut();
86    check_pending_exception!(self.0.env, unsafe {
87      sys::napi_call_function(
88        self.0.env,
89        raw_this,
90        self.0.value,
91        0,
92        ptr::null_mut(),
93        &mut return_value,
94      )
95    })?;
96
97    unsafe { JsUnknown::from_raw(self.0.env, return_value) }
98  }
99
100  /// <https://nodejs.org/api/n-api.html#n_api_napi_new_instance>
101  ///
102  /// This method is used to instantiate a new `JavaScript` value using a given `JsFunction` that represents the constructor for the object.
103  pub fn new_instance<V>(&self, args: &[V]) -> Result<JsObject>
104  where
105    V: NapiRaw,
106  {
107    let mut js_instance = ptr::null_mut();
108    let length = args.len();
109    let raw_args = args
110      .iter()
111      .map(|arg| unsafe { arg.raw() })
112      .collect::<Vec<sys::napi_value>>();
113    check_pending_exception!(self.0.env, unsafe {
114      sys::napi_new_instance(
115        self.0.env,
116        self.0.value,
117        length,
118        raw_args.as_ptr(),
119        &mut js_instance,
120      )
121    })?;
122    Ok(unsafe { JsObject::from_raw_unchecked(self.0.env, js_instance) })
123  }
124
125  /// function name
126  pub fn name(&self) -> Result<String> {
127    let mut name = ptr::null_mut();
128    check_pending_exception!(self.0.env, unsafe {
129      sys::napi_get_named_property(
130        self.0.env,
131        self.0.value,
132        "name\0".as_ptr().cast(),
133        &mut name,
134      )
135    })?;
136    let name_value = unsafe { JsString::from_raw_unchecked(self.0.env, name) };
137    Ok(name_value.into_utf8()?.as_str()?.to_owned())
138  }
139
140  #[cfg(feature = "napi4")]
141  pub fn create_threadsafe_function<T, V, F, ES>(
142    &self,
143    max_queue_size: usize,
144    callback: F,
145  ) -> Result<ThreadsafeFunction<T, ES>>
146  where
147    T: 'static,
148    V: ToNapiValue,
149    F: 'static + Send + FnMut(ThreadSafeCallContext<T>) -> Result<Vec<V>>,
150    ES: crate::threadsafe_function::ErrorStrategy::T,
151  {
152    ThreadsafeFunction::create(self.0.env, self.0.value, max_queue_size, callback)
153  }
154}
napi_h/js_values/function.rs

napi_h/js_values/
function.rs
