gecko-dev/dom/bindings/ToJSValue.h
Ehsan Akhgari 9fe74dfec0 Bug 839838 - Implement DOMRequest.then; r=sicking,bzbarsky
This is implemented by creating a Promise object internally and
forwarding the .then() call to it. Any further callbacks passed to
future .then() calls will be added as callbacks on the same internal
promise object. We also take care of resolving or rejecting the promise
if the success/error event of the DOMRequest object has been fired
before .then() is called.
2014-10-11 09:46:01 -04:00

335 lines
8.7 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* vim: set ts=2 sw=2 et tw=79: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_ToJSValue_h
#define mozilla_dom_ToJSValue_h
#include "mozilla/TypeTraits.h"
#include "mozilla/Assertions.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/TypedArray.h"
#include "jsapi.h"
#include "nsISupports.h"
#include "nsTArray.h"
#include "nsWrapperCache.h"
namespace mozilla {
namespace dom {
// If ToJSValue returns false, it must set an exception on the
// JSContext.
// Accept strings.
bool
ToJSValue(JSContext* aCx,
const nsAString& aArgument,
JS::MutableHandle<JS::Value> aValue);
// Accept booleans.
inline bool
ToJSValue(JSContext* aCx,
bool aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setBoolean(aArgument);
return true;
}
// Accept integer types
inline bool
ToJSValue(JSContext* aCx,
int32_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setInt32(aArgument);
return true;
}
// The uint32_t version is disabled for now because on the super-old b2g
// compiler nsresult and uint32_t are the same type. If someone needs this at
// some point we'll need to figure out how to make it work (e.g. by switching to
// traits structs and using the trick IPC's ParamTraits uses, where a traits
// struct templated on the type inherits from a base traits struct of some sort,
// templated on the same type, or something). Maybe b2g will update to a modern
// compiler before that happens....
#if 0
inline bool
ToJSValue(JSContext* aCx,
uint32_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(aArgument);
return true;
}
#endif
inline bool
ToJSValue(JSContext* aCx,
int64_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(double(aArgument));
return true;
}
inline bool
ToJSValue(JSContext* aCx,
uint64_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(double(aArgument));
return true;
}
// accept floating point types
inline bool
ToJSValue(JSContext* aCx,
float aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(aArgument);
return true;
}
inline bool
ToJSValue(JSContext* aCx,
double aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(aArgument);
return true;
}
// Accept CallbackObjects
inline bool
ToJSValue(JSContext* aCx,
CallbackObject& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setObject(*aArgument.Callback());
return MaybeWrapValue(aCx, aValue);
}
// Accept objects that inherit from nsWrapperCache and nsISupports (e.g. most
// DOM objects).
template <class T>
typename EnableIf<IsBaseOf<nsWrapperCache, T>::value &&
IsBaseOf<nsISupports, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
T& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
// Make sure non-webidl objects don't sneak in here
MOZ_ASSERT(aArgument.IsDOMBinding());
return WrapNewBindingObject(aCx, aArgument, aValue);
}
// Accept typed arrays built from appropriate nsTArray values
template<typename T>
typename EnableIf<IsBaseOf<AllTypedArraysBase, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
const TypedArrayCreator<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
JSObject* obj = aArgument.Create(aCx);
if (!obj) {
return false;
}
aValue.setObject(*obj);
return true;
}
// We don't want to include nsContentUtils here, so use a helper
// function for the nsISupports case.
namespace tojsvalue_detail {
bool
ISupportsToJSValue(JSContext* aCx,
nsISupports* aArgument,
JS::MutableHandle<JS::Value> aValue);
} // namespace tojsvalue_detail
// Accept objects that inherit from nsISupports but not nsWrapperCache (e.g.
// nsIDOMFile).
template <class T>
typename EnableIf<!IsBaseOf<nsWrapperCache, T>::value &&
!IsBaseOf<CallbackObject, T>::value &&
IsBaseOf<nsISupports, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
T& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
return tojsvalue_detail::ISupportsToJSValue(aCx, &aArgument, aValue);
}
// Accept nsRefPtr/nsCOMPtr
template <typename T>
bool
ToJSValue(JSContext* aCx,
const nsCOMPtr<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, *aArgument.get(), aValue);
}
template <typename T>
bool
ToJSValue(JSContext* aCx,
const nsRefPtr<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, *aArgument.get(), aValue);
}
// Accept WebIDL dictionaries
template <class T>
typename EnableIf<IsBaseOf<DictionaryBase, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
const T& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return aArgument.ToObjectInternal(aCx, aValue);
}
// Accept existing JS values (which may not be same-compartment with us
inline bool
ToJSValue(JSContext* aCx, JS::Handle<JS::Value> aArgument,
JS::MutableHandle<JS::Value> aValue)
{
aValue.set(aArgument);
return MaybeWrapValue(aCx, aValue);
}
// Accept existing JS values on the Heap (which may not be same-compartment with us
inline bool
ToJSValue(JSContext* aCx, const JS::Heap<JS::Value>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
aValue.set(aArgument);
return MaybeWrapValue(aCx, aValue);
}
// Accept existing rooted JS values (which may not be same-compartment with us
inline bool
ToJSValue(JSContext* aCx, const JS::Rooted<JS::Value>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
aValue.set(aArgument);
return MaybeWrapValue(aCx, aValue);
}
// Accept nsresult, for use in rejections, and create an XPCOM
// exception object representing that nsresult.
bool
ToJSValue(JSContext* aCx,
nsresult aArgument,
JS::MutableHandle<JS::Value> aValue);
// Accept pointers to other things we accept
template <typename T>
typename EnableIf<IsPointer<T>::value, bool>::Type
ToJSValue(JSContext* aCx,
T aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, *aArgument, aValue);
}
// Accept arrays of other things we accept
template <typename T>
bool
ToJSValue(JSContext* aCx,
T* aArguments,
size_t aLength,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
JS::AutoValueVector v(aCx);
if (!v.resize(aLength)) {
return false;
}
for (size_t i = 0; i < aLength; ++i) {
if (!ToJSValue(aCx, aArguments[i], v[i])) {
return false;
}
}
JSObject* arrayObj = JS_NewArrayObject(aCx, v);
if (!arrayObj) {
return false;
}
aValue.setObject(*arrayObj);
return true;
}
template <typename T>
bool
ToJSValue(JSContext* aCx,
const nsTArray<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, aArgument.Elements(),
aArgument.Length(), aValue);
}
template <typename T>
bool
ToJSValue(JSContext* aCx,
const FallibleTArray<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, aArgument.Elements(),
aArgument.Length(), aValue);
}
template <typename T, int N>
bool
ToJSValue(JSContext* aCx,
const T(&aArgument)[N],
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, aArgument, N, aValue);
}
} // namespace dom
} // namespace mozilla
#endif /* mozilla_dom_ToJSValue_h */