napi-rs/crates/napi/src/js_values/function.rs
2021-11-25 17:53:42 +08:00

136 lines
3.9 KiB
Rust

use std::ptr;
use super::Value;
use crate::bindgen_runtime::TypeName;
#[cfg(feature = "napi4")]
use crate::threadsafe_function::{ThreadSafeCallContext, ThreadsafeFunction};
use crate::{check_status, ValueType};
use crate::{sys, Env, Error, JsObject, JsUnknown, NapiRaw, NapiValue, Result, Status};
pub struct JsFunction(pub(crate) Value);
impl TypeName for JsFunction {
fn type_name() -> &'static str {
"Function"
}
fn value_type() -> crate::ValueType {
ValueType::Function
}
}
/// See [Working with JavaScript Functions](https://nodejs.org/api/n-api.html#n_api_working_with_javascript_functions).
///
/// Example:
/// ```
/// use napi::{JsFunction, CallContext, JsNull, Result};
///
/// #[js_function(1)]
/// pub fn call_function(ctx: CallContext) -> Result<JsNull> {
/// let js_func = ctx.get::<JsFunction>(0)?;
/// let js_string = ctx.env.create_string("hello".as_ref())?.into_unknown()?;
/// js_func.call(None, &[js_string])?;
/// Ok(ctx.env.get_null()?)
/// }
/// ```
impl JsFunction {
/// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
pub fn call<V>(&self, this: Option<&JsObject>, args: &[V]) -> Result<JsUnknown>
where
V: NapiRaw,
{
let raw_this = this
.map(|v| unsafe { v.raw() })
.or_else(|| {
unsafe { Env::from_raw(self.0.env) }
.get_undefined()
.ok()
.map(|u| unsafe { u.raw() })
})
.ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
let raw_args = args
.iter()
.map(|arg| unsafe { arg.raw() })
.collect::<Vec<sys::napi_value>>();
let mut return_value = ptr::null_mut();
check_status!(unsafe {
sys::napi_call_function(
self.0.env,
raw_this,
self.0.value,
args.len(),
raw_args.as_ptr(),
&mut return_value,
)
})?;
unsafe { JsUnknown::from_raw(self.0.env, return_value) }
}
/// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
/// The same with `call`, but without arguments
pub fn call_without_args(&self, this: Option<&JsObject>) -> Result<JsUnknown> {
let raw_this = this
.map(|v| unsafe { v.raw() })
.or_else(|| {
unsafe { Env::from_raw(self.0.env) }
.get_undefined()
.ok()
.map(|u| unsafe { u.raw() })
})
.ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
let mut return_value = ptr::null_mut();
check_status!(unsafe {
sys::napi_call_function(
self.0.env,
raw_this,
self.0.value,
0,
ptr::null_mut(),
&mut return_value,
)
})?;
unsafe { JsUnknown::from_raw(self.0.env, return_value) }
}
/// <https://nodejs.org/api/n-api.html#n_api_napi_new_instance>
///
/// This method is used to instantiate a new `JavaScript` value using a given `JsFunction` that represents the constructor for the object.
pub fn new_instance<V>(&self, args: &[V]) -> Result<JsObject>
where
V: NapiRaw,
{
let mut js_instance = ptr::null_mut();
let length = args.len();
let raw_args = args
.iter()
.map(|arg| unsafe { arg.raw() })
.collect::<Vec<sys::napi_value>>();
check_status!(unsafe {
sys::napi_new_instance(
self.0.env,
self.0.value,
length,
raw_args.as_ptr(),
&mut js_instance,
)
})?;
Ok(unsafe { JsObject::from_raw_unchecked(self.0.env, js_instance) })
}
#[cfg(feature = "napi4")]
pub fn create_threadsafe_function<T, V, F, ES>(
&self,
max_queue_size: usize,
callback: F,
) -> Result<ThreadsafeFunction<T, ES>>
where
T: 'static,
V: NapiRaw,
F: 'static + Send + FnMut(ThreadSafeCallContext<T>) -> Result<Vec<V>>,
ES: crate::threadsafe_function::ErrorStrategy::T,
{
ThreadsafeFunction::create(self.0.env, self.0.value, max_queue_size, callback)
}
}