ladybird/Userland/Libraries/LibWeb/DOM/ExceptionOr.h
Timothy Flynn 95e492de59 LibWeb: Convert throw_dom_exception_if_needed() to ThrowCompletionOr
This changes Web::Bindings::throw_dom_exception_if_needed() to return a
JS::ThrowCompletionOr instead of an Optional. This allows callers to
wrap the invocation with a TRY() macro instead of making a follow-up
call to should_return_empty(). Further, this removes all invocations to
vm.exception() in the generated bindings.
2021-10-31 18:51:07 +01:00

101 lines
2.3 KiB
C++

/*
* Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/NonnullRefPtr.h>
#include <AK/Optional.h>
#include <AK/RefPtr.h>
#include <LibWeb/DOM/DOMException.h>
namespace Web::DOM {
#define ENUMERATE_SIMPLE_WEBIDL_EXCEPTION_TYPES(E) \
E(EvalError) \
E(RangeError) \
E(ReferenceError) \
E(TypeError) \
E(URIError)
#define E(x) x,
enum class SimpleExceptionType {
ENUMERATE_SIMPLE_WEBIDL_EXCEPTION_TYPES(E)
};
#undef E
struct SimpleException {
SimpleExceptionType type;
String message;
};
template<typename ValueType>
class ExceptionOr {
public:
ExceptionOr() requires(IsSame<ValueType, Empty>) = default;
ExceptionOr(const ValueType& result)
: m_result(result)
{
}
ExceptionOr(ValueType&& result)
: m_result(move(result))
{
}
ExceptionOr(NonnullRefPtr<DOMException> exception)
: m_exception(move(exception))
{
}
ExceptionOr(SimpleException exception)
: m_exception(move(exception))
{
}
ExceptionOr(Variant<SimpleException, NonnullRefPtr<DOMException>> exception)
: m_exception(move(exception).template downcast<Empty, SimpleException, NonnullRefPtr<DOMException>>())
{
}
ExceptionOr(ExceptionOr&& other) = default;
ExceptionOr(const ExceptionOr& other) = default;
~ExceptionOr() = default;
ValueType& value() requires(!IsSame<ValueType, Empty>)
{
return m_result.value();
}
ValueType release_value() requires(!IsSame<ValueType, Empty>)
{
return m_result.release_value();
}
Variant<SimpleException, NonnullRefPtr<DOMException>> exception() const
{
return m_exception.template downcast<SimpleException, NonnullRefPtr<DOMException>>();
}
bool is_exception() const
{
return !m_exception.template has<Empty>();
}
private:
Optional<ValueType> m_result;
// https://webidl.spec.whatwg.org/#idl-exceptions
Variant<Empty, SimpleException, NonnullRefPtr<DOMException>> m_exception {};
};
template<>
class ExceptionOr<void> : public ExceptionOr<Empty> {
public:
using ExceptionOr<Empty>::ExceptionOr;
};
}