This factors out all of the parsing code from the network library

chrome/browser/chromeos/cros/network_parser.h

+// Copyright (c) 2011 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 CHROME_BROWSER_CHROMEOS_CROS_NETWORK_PARSER_H_
+#define CHROME_BROWSER_CHROMEOS_CROS_NETWORK_PARSER_H_
+#pragma once
+
+#include <string>
+#include <map>
+
+#include "base/scoped_ptr.h"
+#include "chrome/browser/chromeos/cros/network_library.h"
+
+class Value;
+
+namespace chromeos {
+
+class NetworkDevice;
+
+// This turns an array of string-to-enum-value mappings into a class
+// that can cache the mapping and do quick lookups using an actual map
+// class.  Usage is something like:
+//
+// const char kKey1[] = "key1";
+// const char kKey2[] = "key2";
+//
+// enum EnumFoo {
+//   UNKNOWN = 0,
+//   FOO = 1,
+//   BAR = 2,
+// };
+//
+// const EnumMapper<EnumFoo>::Pair index_table[] = {
+//   { kKey1, FOO },
+//   { kKey2, BAR },
+// };
+//
+// EnumMapper<EnumFoo> mapper(index_table, arraysize(index_table), UNKNOWN);
+// EnumFoo value = mapper.Get(kKey1);  // Returns FOO.
+// EnumFoo value = mapper.Get('boo');  // Returns UNKNOWN.
+template <typename EnumType>
+class EnumMapper {
+ public:
+  struct Pair {
+    const char* key;
+    const EnumType value;
+  };
+
+  EnumMapper(const Pair* list, size_t num_entries, EnumType unknown)
+      : unknown_value_(unknown) {
+    for (size_t i = 0; i < num_entries; ++i, ++list)
+      enum_map_[list->key] = list->value;
+  }
+
+  EnumType Get(const std::string& type) const {
+    EnumMapConstIter iter = enum_map_.find(type);
+    if (iter != enum_map_.end())
+      return iter->second;
+    return unknown_value_;
+  }
+
+ private:
+  typedef typename std::map<std::string, EnumType> EnumMap;
+  typedef typename EnumMap::const_iterator EnumMapConstIter;
+  EnumMap enum_map_;
+  EnumType unknown_value_;
+  DISALLOW_COPY_AND_ASSIGN(EnumMapper);
+};
+
+// This takes a Value of a particular form, and maps the keys in the
+// dictionary to a NetworkDevice object to initialize it properly.
+// Subclasses of this can then customize its methods to parse either
+// libcros (flimflam) data or network setup information obtained from
+// policy or setup file import depending on the EnumMapper supplied.
+class NetworkDeviceParser {
+ public:
+  virtual NetworkDevice* CreateDeviceFromInfo(const std::string& device_path,
+                                              const DictionaryValue& info);
+  virtual bool UpdateDeviceFromInfo(const DictionaryValue& info,
+                                    NetworkDevice* device);
+  virtual bool UpdateStatus(const std::string& key,
+                            const Value& value,
+                            NetworkDevice* device,
+                            PropertyIndex* index);
+ protected:
+  // The NetworkDeviceParser does not take ownership of the |mapper|.
+  explicit NetworkDeviceParser(const EnumMapper<PropertyIndex>* mapper);
+  virtual ~NetworkDeviceParser();
+
+  virtual bool ParseValue(PropertyIndex index,
+                          const Value& value,
+                          NetworkDevice* device) = 0;
+  virtual ConnectionType ParseType(const std::string& type) = 0;
+
+  const EnumMapper<PropertyIndex>& mapper() const {
+    return *mapper_;
+  }
+
+ private:
+  const EnumMapper<PropertyIndex>* mapper_;
+  DISALLOW_COPY_AND_ASSIGN(NetworkDeviceParser);
+};
+
+// This takes a Value of a particular form, and uses the keys in the
+// dictionary to create Network (WiFiNetwork, EthernetNetwork, etc.)
+// objects and initialize them properly.  Subclasses of this can then
+// customize its methods to parse other forms of input dictionaries.
+class NetworkParser {
+ public:
+  // Called from the NetworkLibrary when a new network is encountered.

[stevenjb, 2011/08/05 18:46:58]

More generic description (since it might be used from the policy code)? Maybe ad
a similar comment to NetworkDeviceParser?

+  virtual Network* CreateNetworkFromInfo(const std::string& service_path,
+                                         const DictionaryValue& info);
+

[stevenjb, 2011/08/05 18:46:58]

Should probably comment the following methods also, for this and
NetworkDeviceParser.

[Greg Spencer (Chromium), 2011/08/11 22:19:32]

Done.

+  virtual bool UpdateNetworkFromInfo(const DictionaryValue& info,
+                                     Network* network);
+
+  virtual bool UpdateStatus(const std::string& key,
+                            const Value& value,
+                            Network* network,
+                            PropertyIndex* index);
+ protected:
+  // The NetworkParser does not take ownership of the |mapper|.
+  explicit NetworkParser(const EnumMapper<PropertyIndex>* mapper);
+  virtual ~NetworkParser();
+
+  static Network* CreateNewNetwork(ConnectionType type,
+                                   const std::string& service_path);

[stevenjb, 2011/08/05 18:46:58]

Does this need to be a static member, or could it be moved into a local
namespace in the .cc file?

[Greg Spencer (Chromium), 2011/08/11 22:19:32]

Huh.  I guess I changed things.  It used to be needed in several places, but I
guess I factored that out again without realizing it.  I'll move this into an
anonymous namespace inside the .cc.

+
+  virtual bool ParseValue(PropertyIndex index,
+                          const Value& value,
+                          Network* network) = 0;
+  virtual ConnectionType ParseType(const std::string& type) = 0;
+  virtual ConnectionType ParseTypeFromDictionary(
+      const DictionaryValue& info) = 0;
+  virtual ConnectionMode ParseMode(const std::string& mode) = 0;
+  virtual ConnectionState ParseState(const std::string& state) = 0;
+  virtual ConnectionError ParseError(const std::string& error) = 0;
+
+  const EnumMapper<PropertyIndex>& mapper() const {
+    return *mapper_;
+  }
+
+ private:
+  const EnumMapper<PropertyIndex>* mapper_;
+  DISALLOW_COPY_AND_ASSIGN(NetworkParser);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_CROS_NETWORK_PARSER_H_