(Reland reverted r52628 after fix)

Refactor json automation interface for pyauto hooks.
Reduces the number of lines you need to add per new automation hook. Shaves
off several lines of code.

Refactor pyauto.py to obviate raising exception in case the json interfaces produces an error string.

Review URL: http://codereview.chromium.org/2898001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@52649 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 40 insertions, 0 deletions

diff --git a/chrome/browser/automation/automation_provider_json.h b/chrome/browser/automation/automation_provider_json.h
new file mode 100644
index 0000000..a203c58
--- /dev/null
+++ b/chrome/browser/automation/automation_provider_json.h
@@ -0,0 +1,40 @@
+// Copyright (c) 2010 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.
+
+// Support utilities for the JSON automation interface used by PyAuto.
+
+#ifndef CHROME_BROWSER_AUTOMATION_AUTOMATION_PROVIDER_JSON_H_
+#define CHROME_BROWSER_AUTOMATION_AUTOMATION_PROVIDER_JSON_H_
+
+#include <string>
+
+#include "base/values.h"
+#include "ipc/ipc_message.h"
+#include "chrome/browser/automation/automation_provider.h"
+
+// Helper to ensure we always send a reply message for JSON automation requests.
+class AutomationJSONReply {
+ public:
+  // Creates a new reply object for the IPC message |reply_message| for
+  // |provider|. The caller is expected to call SendSuccess() or SendError()
+  // before destroying this object.
+  AutomationJSONReply(AutomationProvider* provider,
+                      IPC::Message* reply_message);
+
+  ~AutomationJSONReply();
+
+  // Send a success reply along with data contained in |value|.
+  // An empty message will be sent if |value| is NULL.
+  void SendSuccess(const Value* value);
+
+  // Send an error reply along with error message |error_message|.
+  void SendError(const std::string& error_message);
+
+ private:
+  AutomationProvider* provider_;
+  IPC::Message* message_;
+};
+
+#endif  // CHROME_BROWSER_AUTOMATION_AUTOMATION_PROVIDER_JSON_H_
+