Struct rusty_v8::TryCatch

#[repr(transparent)]pub struct TryCatch<'tc>(_, _);

An external exception handler.

Implementations

impl<'tc> TryCatch<'tc>

pub fn new(scope: &mut impl InIsolate) -> TryCatchScope<'tc>

Creates a new try/catch block. Note that all TryCatch blocks should be stack allocated because the memory location itself is compared against JavaScript try/catch blocks.

pub fn has_caught(&self) -> bool

Returns true if an exception has been caught by this try/catch block.

pub fn can_continue(&self) -> bool

For certain types of exceptions, it makes no sense to continue execution.

If CanContinue returns false, the correct action is to perform any C++ cleanup needed and then return. If CanContinue returns false and HasTerminated returns true, it is possible to call CancelTerminateExecution in order to continue calling into the engine.

pub fn has_terminated(&self) -> bool

Returns true if an exception has been caught due to script execution being terminated.

There is no JavaScript representation of an execution termination exception. Such exceptions are thrown when the TerminateExecution methods are called to terminate a long-running script.

If such an exception has been thrown, HasTerminated will return true, indicating that it is possible to call CancelTerminateExecution in order to continue calling into the engine.

pub fn exception<'sc>(
    &self,
    scope: &mut impl ToLocal<'sc>
) -> Option<Local<'sc, Value>>

Returns the exception caught by this try/catch block. If no exception has been caught an empty handle is returned.

Note: v8.h states that "the returned handle is valid until this TryCatch block has been destroyed". This is incorrect; the return value lives no longer and no shorter than the active HandleScope at the time this method is called. An issue has been opened about this in the V8 bug tracker: https://bugs.chromium.org/p/v8/issues/detail?id=10537.

pub fn message<'sc>(
    &self,
    scope: &mut impl ToLocal<'sc>
) -> Option<Local<'sc, Message>>

Returns the message associated with this exception. If there is no message associated an empty handle is returned.

Note: the remark about the lifetime for the exception() return value applies here too.

pub fn stack_trace<'sc>(
    &self,
    scope: &mut impl ToLocal<'sc>,
    context: Local<Context>
) -> Option<Local<'sc, Value>>

Returns the .stack property of the thrown object. If no .stack property is present an empty handle is returned.

pub fn reset(&mut self)

Clears any exceptions that may have been caught by this try/catch block. After this method has been called, HasCaught() will return false. Cancels the scheduled exception if it is caught and ReThrow() is not called before.

It is not necessary to clear a try/catch block before using it again; if another exception is thrown the previously caught exception will just be overwritten. However, it is often a good idea since it makes it easier to determine which operation threw a given exception.

pub fn rethrow(&mut self) -> Option<Local<Value>>

Throws the exception caught by this TryCatch in a way that avoids it being caught again by this same TryCatch. As with ThrowException it is illegal to execute any JavaScript operations after calling ReThrow; the caller must return immediately to where the exception is caught.

This function returns the undefined value when successful, or None if no exception was caught and therefore there was nothing to rethrow.

pub fn is_verbose(&self) -> bool

Returns true if verbosity is enabled.

pub fn set_verbose(&mut self, value: bool)

Set verbosity of the external exception handler.

By default, exceptions that are caught by an external exception handler are not reported. Call SetVerbose with true on an external exception handler to have exceptions caught by the handler reported as if they were not caught.

pub fn set_capture_message(&mut self, value: bool)

Set whether or not this TryCatch should capture a Message object which holds source information about where the exception occurred. True by default.