chrome/browser/extensions/extension_error_reporter.h

   1 // Copyright (c) 2011 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_ERROR_REPORTER_H_
   6 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_ERROR_REPORTER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/observer_list.h"
  12 #include "base/strings/string16.h"
  13
  14 namespace base {
  15 class MessageLoop;
  16 class FilePath;
  17 }
  18
  19 namespace content {
  20 class BrowserContext;
  21 }
  22
  23 // Exposes an easy way for the various components of the extension system to
  24 // report errors. This is a singleton that lives on the UI thread, with the
  25 // exception of ReportError() which may be called from any thread.
  26 // TODO(aa): Hook this up to about:extensions, when we have about:extensions.
  27 // TODO(aa): Consider exposing directly, or via a helper, to the renderer
  28 // process and plumbing the errors out to the browser.
  29 // TODO(aa): Add ReportError(extension_id, message, be_noisy), so that we can
  30 // report errors that are specific to a particular extension.
  31 class ExtensionErrorReporter {
  32  public:
  33   class Observer {
  34    public:
  35     virtual ~Observer() {}
  36
  37     // Called when an unpacked extension fails to load.
  38     virtual void OnLoadFailure(content::BrowserContext* browser_context,
  39                                const base::FilePath& extension_path,
  40                                const std::string& error) = 0;
  41   };
  42
  43   // Initializes the error reporter. Must be called before any other methods
  44   // and on the UI thread.
  45   static void Init(bool enable_noisy_errors);
  46
  47   // Get the singleton instance.
  48   static ExtensionErrorReporter* GetInstance();
  49
  50   // Report an extension load error. This forwards to ReportError() after
  51   // sending an EXTENSION_LOAD_ERROR notification.
  52   // TODO(rdevlin.cronin): There's a lot wrong with this. But some of our
  53   // systems rely on the notification. Investigate what it will take to remove
  54   // the notification and this method.
  55   void ReportLoadError(const base::FilePath& extension_path,
  56                        const std::string& error,
  57                        content::BrowserContext* browser_context,
  58                        bool be_noisy);
  59
  60   // Report an error. Errors always go to VLOG(1). Optionally, they can also
  61   // cause a noisy alert box.
  62   void ReportError(const base::string16& message, bool be_noisy);
  63
  64   // Get the errors that have been reported so far.
  65   const std::vector<base::string16>* GetErrors();
  66
  67   // Clear the list of errors reported so far.
  68   void ClearErrors();
  69
  70   void AddObserver(Observer* observer);
  71
  72   void RemoveObserver(Observer* observer);
  73
  74  private:
  75   static ExtensionErrorReporter* instance_;
  76
  77   explicit ExtensionErrorReporter(bool enable_noisy_errors);
  78   ~ExtensionErrorReporter();
  79
  80   base::MessageLoop* ui_loop_;
  81   std::vector<base::string16> errors_;
  82   bool enable_noisy_errors_;
  83
  84   base::ObserverList<Observer> observers_;
  85 };
  86
  87 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_ERROR_REPORTER_H_