1 // Copyright (c) 2010 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 #include "chrome/browser/extensions/extension_i18n_api.h"
6
7 #include "base/string_piece.h"
8 #include "base/utf_string_conversions.h"
9 #include "chrome/browser/prefs/pref_service.h"
10 #include "chrome/browser/profiles/profile.h"
11 #include "chrome/common/pref_names.h"
12
13 // Errors.
14 static const char kEmptyAcceptLanguagesError[] = "accept-languages is empty.";
15
RunImpl()16 bool GetAcceptLanguagesFunction::RunImpl() {
17 string16 acceptLanguages =
18 UTF8ToUTF16(profile()->GetPrefs()->GetString(prefs::kAcceptLanguages));
19 // Currently, there are 2 ways to set browser's accept-languages: through UI
20 // or directly modify the preference file. The accept-languages set through
21 // UI is guranteed to be valid, and the accept-languages string returned from
22 // profile()->GetPrefs()->GetString(prefs::kAcceptLanguages) is guranteed to
23 // be valid and well-formed, which means each accept-langauge is a valid
24 // code, and accept-languages are seperatd by "," without surrrounding
25 // spaces. But we do not do any validation (either the format or the validity
26 // of the language code) on accept-languages set through editing preference
27 // file directly. So, here, we're adding extra checks to be resistant to
28 // crashes caused by data corruption.
29 result_.reset(new ListValue());
30 if (acceptLanguages.empty()) {
31 error_ = kEmptyAcceptLanguagesError;
32 return false;
33 }
34 size_t begin = 0;
35 size_t end;
36 while (1) {
37 end = acceptLanguages.find(',', begin);
38 if (end > begin) {
39 // Guard against a malformed value with multiple "," in a row.
40 string16 acceptLang = acceptLanguages.substr(begin, end - begin);
41 static_cast<ListValue*>(result_.get())->
42 Append(Value::CreateStringValue(acceptLang));
43 }
44 begin = end + 1;
45 // 'begin >= acceptLanguages.length()' to guard against a value
46 // ending with ','.
47 if (end == string16::npos || begin >= acceptLanguages.length())
48 break;
49 }
50 if (static_cast<ListValue*>(result_.get())->GetSize() == 0) {
51 error_ = kEmptyAcceptLanguagesError;
52 return false;
53 }
54 return true;
55 }
56