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// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef GIN_DATA_OBJECT_BUILDER_H_
#define GIN_DATA_OBJECT_BUILDER_H_
#include <utility>
#include "base/check.h"
#include "base/strings/string_piece.h"
#include "gin/converter.h"
#include "gin/gin_export.h"
#include "v8/include/v8-forward.h"
#include "v8/include/v8-object.h"
namespace gin {
// Constructs a JavaScript object with a series of data properties.
// (As with default data properties in JavaScript, these properties are
// configurable, writable and enumerable.)
//
// Values are automatically converted using gin::Converter, though if
// using a type where the conversion may fail, callers must convert ahead of
// time.
//
// This class avoids the pitfall of using v8::Object::Set, which may invoke
// setters on the object prototype.
//
// Expected usage:
// v8::Local<v8::Object> object = gin::DataObjectBuilder(isolate)
// .Set("boolean", true)
// .Set("integer", 42)
// .Build();
//
// Because this builder class contains local handles, callers must ensure it
// does not outlive the scope in which it is created.
class GIN_EXPORT DataObjectBuilder {
public:
explicit DataObjectBuilder(v8::Isolate* isolate);
DataObjectBuilder(const DataObjectBuilder&) = delete;
DataObjectBuilder& operator=(const DataObjectBuilder&) = delete;
template <typename T>
DataObjectBuilder& Set(base::StringPiece key, T&& value) {
DCHECK(!object_.IsEmpty());
v8::Local<v8::String> v8_key = StringToSymbol(isolate_, key);
v8::Local<v8::Value> v8_value =
ConvertToV8(isolate_, std::forward<T>(value));
CHECK(object_->CreateDataProperty(context_, v8_key, v8_value).ToChecked());
return *this;
}
template <typename T>
DataObjectBuilder& Set(uint32_t index, T&& value) {
DCHECK(!object_.IsEmpty());
v8::Local<v8::Value> v8_value =
ConvertToV8(isolate_, std::forward<T>(value));
CHECK(object_->CreateDataProperty(context_, index, v8_value).ToChecked());
return *this;
}
v8::Local<v8::Object> Build() {
DCHECK(!object_.IsEmpty());
v8::Local<v8::Object> result = object_;
object_.Clear();
return result;
}
private:
v8::Isolate* isolate_;
v8::Local<v8::Context> context_;
v8::Local<v8::Object> object_;
};
} // namespace gin
#endif // GIN_DATA_OBJECT_BUILDER_H_
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