Struct Ctx

pub struct Ctx<'js> { /* private fields */ }

Context in use, passed to Context::with.

Implementations

impl<'js> Ctx<'js>

pub fn eval<V: FromJs<'js>, S: Into<Vec<u8>>>(&self, source: S) -> Result<V>

Evaluate a script in global context.

pub fn eval_promise<S: Into<Vec<u8>>>(&self, source: S) -> Result<Promise<'js>>

Evaluate a script in global context with top level await support.

This function always returns a promise which resolves to the result of the evaluated expression.

pub fn eval_with_options<V: FromJs<'js>, S: Into<Vec<u8>>>( &self, source: S, options: EvalOptions, ) -> Result<V>

Evaluate a script with the given options.

pub fn eval_file<V: FromJs<'js>, P: AsRef<Path>>(&self, path: P) -> Result<V>

Evaluate a script directly from a file.

pub fn eval_file_with_options<V: FromJs<'js>, P: AsRef<Path>>( &self, path: P, options: EvalOptions, ) -> Result<V>

pub fn globals(&self) -> Object<'js>

Returns the global object of this context.

pub fn catch(&self) -> Value<'js>

Returns the last raised JavaScript exception, if there is no exception the JavaScript value null is returned.

Usage

if let Err(Error::Exception) = ctx.eval::<(),_>("throw 3"){
    assert_eq!(ctx.catch().as_int(),Some(3));
}

pub fn throw(&self, value: Value<'js>) -> Error

Throws a JavaScript value as a new exception. Always returns Error::Exception;

pub fn json_parse<S>(&self, json: S) -> Result<Value<'js>>

where S: Into<Vec<u8>>,

Parse json into a JavaScript value.

pub fn json_stringify<V>(&self, value: V) -> Result<Option<String<'js>>>

where V: IntoJs<'js>,

Stringify a JavaScript value into its JSON representation

pub fn json_stringify_replacer<V, R>( &self, value: V, replacer: R, ) -> Result<Option<String<'js>>>

where V: IntoJs<'js>, R: IntoJs<'js>,

Stringify a JavaScript value into its JSON representation with a possible replacer.

The replacer is the same as the replacer argument for JSON.stringify. It is is a function that alters the behavior of the stringification process.

pub fn json_stringify_replacer_space<V, R, S>( &self, value: V, replacer: R, space: S, ) -> Result<Option<String<'js>>>

where V: IntoJs<'js>, R: IntoJs<'js>, S: IntoJs<'js>,

Stringify a JavaScript value into its JSON representation with a possible replacer and spaces

The replacer is the same as the replacer argument for JSON.stringify. It is is a function that alters the behavior of the stringification process.

Space is either a number or a string which is used to insert whitespace into the output string for readability purposes. This behaves the same as the space argument for JSON.stringify.

pub fn promise(&self) -> Result<(Promise<'js>, Function<'js>, Function<'js>)>

Creates javascipt promise along with its reject and resolve functions.

pub fn execute_pending_job(&self) -> bool

Executes a quickjs job.

Returns wether a job was actually executed. If this function returned false, no job was pending.

pub fn spawn<F>(&self, future: F)

where F: Future<Output = ()> + 'js,

Available on crate feature futures only.

Spawn future using configured async runtime

pub unsafe fn from_raw_invariant( ctx: NonNull<JSContext>, inv: Invariant<'js>, ) -> Self

Create a new Ctx from a pointer to the context and a invariant lifetime.

Safety

User must ensure that a lock was acquired over the runtime and that invariant is a unique lifetime which can’t be coerced to a lifetime outside the scope of the lock of to the lifetime of another runtime.

pub unsafe fn from_raw(ctx: NonNull<JSContext>) -> Self

Create a new Ctx from a pointer to the context and a invariant lifetime.

Safety

User must ensure that a lock was acquired over the runtime and that invariant is a unique lifetime which can’t be coerced to a lifetime outside the scope of the lock of to the lifetime of another runtime.

pub fn script_or_module_name(&self, stack_level: isize) -> Option<Atom<'js>>

Returns the name of the current module or script that is running.

It called from a javascript callback it will return the current running javascript script name. Otherwise it will return none.

pub fn run_gc(&self)

Runs the quickjs garbage collector for a cycle.

Quickjs uses reference counting with a collection cycle for cyclic references. This runs the cyclic reference collector cycle, types which are not part of a reference cycle will be freed the momement their reference count becomes zero.

pub fn store_userdata<U>( &self, data: U, ) -> StdResult<Option<Box<U>>, UserDataError<U>>

where U: JsLifetime<'js>, U::Changed<'static>: Any,

Store a type in the runtime which can be retrieved later with Ctx::userdata.

Returns the value from the argument if the userdata is currently being accessed and insertion is not possible. Otherwise returns the exising value for this type if it existed.

pub fn remove_userdata<U>(&self) -> StdResult<Option<Box<U>>, UserDataError<()>>

where U: JsLifetime<'js>, U::Changed<'static>: Any,

Remove the userdata of the given type from the userdata storage.

Returns Err(()) if the userdata is currently being accessed and removing isn’t possible. Returns Ok(None) if userdata of the given type wasn’t inserted.

pub fn userdata<U>(&self) -> Option<UserDataGuard<'_, U>>

where U: JsLifetime<'js>, U::Changed<'static>: Any,

Retrieves a borrow to the userdata of the given type from the userdata storage.

Returns None if userdata of the given type wasn’t inserted.

pub fn as_raw(&self) -> NonNull<JSContext>

Returns the pointer to the C library context.

Trait Implementations

impl<'js> Clone for Ctx<'js>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'js> Debug for Ctx<'js>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'js> Drop for Ctx<'js>

fn drop(&mut self)

Executes the destructor for this type.

impl<'js> FromParam<'js> for Ctx<'js>

fn param_requirement() -> ParamRequirement

The parameters requirements this value requires.

fn from_param<'a>(params: &mut ParamsAccessor<'a, 'js>) -> Result<Self>

Convert from a parameter value.

impl<'js> Trace<'js> for Ctx<'js>

fn trace<'a>(&self, tracer: Tracer<'a, 'js>)

impl Send for Ctx<'_>