dbus/values_util.h: Add functions to append collection type values to message.

dbus/values_util.h

 // Copyright (c) 2012 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 DBUS_VALUES_UTIL_H_
 #define DBUS_VALUES_UTIL_H_
 
 #include "dbus/dbus_export.h"
 
 namespace base {
 class Value;
 }
 
 namespace dbus {
 
 class MessageReader;
 class MessageWriter;
 
 // Pops a value from |reader| as a base::Value.
 // Returns NULL if an error occurs.
 // Note: Integer values larger than int32 (including uint32) are converted to
 // double.  Non-string diciontary keys are converted to strings.
 CHROME_DBUS_EXPORT base::Value* PopDataAsValue(MessageReader* reader);
 
-// Appends a basic type value to |writer|.
+// Appends a basic type value to |writer|. Basic types are BOOLEAN, INTEGER,
+// DOUBLE, and STRING. Use this function for values that are known to be basic
+// types and to handle basic type members of collections that should not
+// have type "a{sv}" or "av". Otherwise, use AppendValueData.
 CHROME_DBUS_EXPORT void AppendBasicTypeValueData(MessageWriter* writer,
                                                  const base::Value& value);
 
-// Appends a basic type value to |writer| as a variant.
+// Appends a basic type value to |writer| as a variant. Basic types are BOOLEAN,
+// INTEGER, DOUBLE, and STRING. Use this function for values that are known to
+// be basic types and to handle basic type members of collections that should
+// not have type "a{sv}" or "av". Otherwise, use AppendValueDataAsVariant.
 CHROME_DBUS_EXPORT void AppendBasicTypeValueDataAsVariant(
     MessageWriter* writer,
     const base::Value& value);
 
+// Appends a value to |writer|. Value can be a basic type, as well as a
+// collection type, such as dictionary or list. Collections will be recursively
+// written as variant containers, i.e. dictionaries will be written with type
+// a{sv} and lists with type av. Any sub-dictionaries or sub-lists will also
+// have these types.
+CHROME_DBUS_EXPORT void AppendValueData(MessageWriter* writer,
+                                        const base::Value& value);
+
+// Appends a value to |writer| as a variant. Value can be a basic type, as well
+// as a collection type, such as dictionary or list. Collections will be
+// recursively written as variant containers, i.e. dictionaries will be written
+// with type a{sv} and lists with type av. Any sub-dictionaries or sub-lists
+// will also have these types.
+CHROME_DBUS_EXPORT void AppendValueDataAsVariant(MessageWriter* writer,
+                                                 const base::Value& value);
+
 }  // namespace dbus
 
 #endif  // DBUS_VALUES_UTIL_H_