gin/converter.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef GIN_CONVERTER_H_
   6 #define GIN_CONVERTER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/strings/string_piece.h"
  12 #include "v8/include/v8.h"
  13
  14 namespace gin {
  15
  16 template<typename T, typename Enable = void>
  17 struct Converter {};
  18
  19 template<>
  20 struct Converter<bool> {
  21   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  22                                     bool val);
  23   static bool FromV8(v8::Isolate* isolate,
  24                      v8::Handle<v8::Value> val,
  25                      bool* out);
  26 };
  27
  28 template<>
  29 struct Converter<int32_t> {
  30   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  31                                     int32_t val);
  32   static bool FromV8(v8::Isolate* isolate,
  33                      v8::Handle<v8::Value> val,
  34                      int32_t* out);
  35 };
  36
  37 template<>
  38 struct Converter<uint32_t> {
  39   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  40                                     uint32_t val);
  41   static bool FromV8(v8::Isolate* isolate,
  42                      v8::Handle<v8::Value> val,
  43                      uint32_t* out);
  44 };
  45
  46 template<>
  47 struct Converter<int64_t> {
  48   // Warning: JavaScript cannot represent 64 integers precisely.
  49   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  50                                     int64_t val);
  51   static bool FromV8(v8::Isolate* isolate,
  52                      v8::Handle<v8::Value> val,
  53                      int64_t* out);
  54 };
  55
  56 template<>
  57 struct Converter<uint64_t> {
  58   // Warning: JavaScript cannot represent 64 integers precisely.
  59   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  60                                     uint64_t val);
  61   static bool FromV8(v8::Isolate* isolate,
  62                      v8::Handle<v8::Value> val,
  63                      uint64_t* out);
  64 };
  65
  66 template<>
  67 struct Converter<double> {
  68   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  69                                     double val);
  70   static bool FromV8(v8::Isolate* isolate,
  71                      v8::Handle<v8::Value> val,
  72                      double* out);
  73 };
  74
  75 template<>
  76 struct Converter<base::StringPiece> {
  77   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  78                                     const base::StringPiece& val);
  79   // No conversion out is possible because StringPiece does not contain storage.
  80 };
  81
  82 template<>
  83 struct Converter<std::string> {
  84   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
  85                                     const std::string& val);
  86   static bool FromV8(v8::Isolate* isolate,
  87                      v8::Handle<v8::Value> val,
  88                      std::string* out);
  89 };
  90
  91 template<>
  92 struct Converter<v8::Handle<v8::Function> > {
  93   static bool FromV8(v8::Isolate* isolate,
  94                      v8::Handle<v8::Value> val,
  95                      v8::Handle<v8::Function>* out);
  96 };
  97
  98 template<>
  99 struct Converter<v8::Handle<v8::Object> > {
 100   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
 101                                     v8::Handle<v8::Object> val);
 102   static bool FromV8(v8::Isolate* isolate,
 103                      v8::Handle<v8::Value> val,
 104                      v8::Handle<v8::Object>* out);
 105 };
 106
 107 template<>
 108 struct Converter<v8::Handle<v8::ArrayBuffer> > {
 109   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
 110                                     v8::Handle<v8::ArrayBuffer> val);
 111   static bool FromV8(v8::Isolate* isolate,
 112                      v8::Handle<v8::Value> val,
 113                      v8::Handle<v8::ArrayBuffer>* out);
 114 };
 115
 116 template<>
 117 struct Converter<v8::Handle<v8::External> > {
 118   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
 119                                     v8::Handle<v8::External> val);
 120   static bool FromV8(v8::Isolate* isolate,
 121                      v8::Handle<v8::Value> val,
 122                      v8::Handle<v8::External>* out);
 123 };
 124
 125 template<>
 126 struct Converter<v8::Handle<v8::Value> > {
 127   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
 128                                     v8::Handle<v8::Value> val);
 129   static bool FromV8(v8::Isolate* isolate,
 130                      v8::Handle<v8::Value> val,
 131                      v8::Handle<v8::Value>* out);
 132 };
 133
 134 template<typename T>
 135 struct Converter<std::vector<T> > {
 136   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
 137                                     const std::vector<T>& val) {
 138     v8::Handle<v8::Array> result(
 139         v8::Array::New(isolate, static_cast<int>(val.size())));
 140     for (size_t i = 0; i < val.size(); ++i) {
 141       result->Set(static_cast<int>(i), Converter<T>::ToV8(isolate, val[i]));
 142     }
 143     return result;
 144   }
 145
 146   static bool FromV8(v8::Isolate* isolate,
 147                      v8::Handle<v8::Value> val,
 148                      std::vector<T>* out) {
 149     if (!val->IsArray())
 150       return false;
 151
 152     std::vector<T> result;
 153     v8::Handle<v8::Array> array(v8::Handle<v8::Array>::Cast(val));
 154     uint32_t length = array->Length();
 155     for (uint32_t i = 0; i < length; ++i) {
 156       T item;
 157       if (!Converter<T>::FromV8(isolate, array->Get(i), &item))
 158         return false;
 159       result.push_back(item);
 160     }
 161
 162     out->swap(result);
 163     return true;
 164   }
 165 };
 166
 167 // Convenience functions that deduce T.
 168 template<typename T>
 169 v8::Handle<v8::Value> ConvertToV8(v8::Isolate* isolate,
 170                                   T input) {
 171   return Converter<T>::ToV8(isolate, input);
 172 }
 173
 174 inline v8::Handle<v8::String> StringToV8(v8::Isolate* isolate,
 175                                          const base::StringPiece& input) {
 176   return ConvertToV8(isolate, input).As<v8::String>();
 177 }
 178
 179 v8::Handle<v8::String> StringToSymbol(v8::Isolate* isolate,
 180                                       const base::StringPiece& val);
 181
 182 template<typename T>
 183 bool ConvertFromV8(v8::Isolate* isolate, v8::Handle<v8::Value> input,
 184                    T* result) {
 185   return Converter<T>::FromV8(isolate, input, result);
 186 }
 187
 188 std::string V8ToString(v8::Handle<v8::Value> value);
 189
 190 }  // namespace gin
 191
 192 #endif  // GIN_CONVERTER_H_