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_DICTIONARY_H_
6 #define GIN_DICTIONARY_H_
7 
8 #include "gin/converter.h"
9 #include "gin/gin_export.h"
10 
11 namespace gin {
12 
13 // Dictionary is useful when writing bindings for a function that either
14 // receives an arbitrary JavaScript object as an argument or returns an
15 // arbitrary JavaScript object as a result. For example, Dictionary is useful
16 // when you might use the |dictionary| type in WebIDL:
17 //
18 //   http://heycam.github.io/webidl/#idl-dictionaries
19 //
20 // WARNING: You cannot retain a Dictionary object in the heap. The underlying
21 //          storage for Dictionary is tied to the closest enclosing
22 //          v8::HandleScope. Generally speaking, you should store a Dictionary
23 //          on the stack.
24 //
25 class GIN_EXPORT Dictionary {
26  public:
27   explicit Dictionary(v8::Isolate* isolate);
28   Dictionary(v8::Isolate* isolate, v8::Local<v8::Object> object);
29   Dictionary(const Dictionary& other);
30   ~Dictionary();
31 
32   static Dictionary CreateEmpty(v8::Isolate* isolate);
33 
34   template<typename T>
Get(const std::string & key,T * out)35   bool Get(const std::string& key, T* out) {
36     v8::Local<v8::Value> val;
37     if (!object_->Get(isolate_->GetCurrentContext(), StringToV8(isolate_, key))
38              .ToLocal(&val)) {
39       return false;
40     }
41     return ConvertFromV8(isolate_, val, out);
42   }
43 
44   template <typename T>
Set(const std::string & key,const T & val)45   bool Set(const std::string& key, const T& val) {
46     v8::Local<v8::Value> v8_value;
47     if (!TryConvertToV8(isolate_, val, &v8_value))
48       return false;
49     v8::Maybe<bool> result =
50         object_->Set(isolate_->GetCurrentContext(), StringToV8(isolate_, key),
51                     v8_value);
52     return !result.IsNothing() && result.FromJust();
53   }
54 
isolate()55   v8::Isolate* isolate() const { return isolate_; }
56 
57  private:
58   friend struct Converter<Dictionary>;
59 
60   // TODO(aa): Remove this. Instead, get via FromV8(), Set(), and Get().
61   v8::Isolate* isolate_;
62   v8::Local<v8::Object> object_;
63 };
64 
65 template<>
66 struct GIN_EXPORT Converter<Dictionary> {
67   static v8::Local<v8::Value> ToV8(v8::Isolate* isolate,
68                                     Dictionary val);
69   static bool FromV8(v8::Isolate* isolate,
70                      v8::Local<v8::Value> val,
71                      Dictionary* out);
72 };
73 
74 }  // namespace gin
75 
76 #endif  // GIN_DICTIONARY_H_
77