Loads local resources from current locale subtree if available, if not it fal...

chrome/common/extensions/extension_resource.cc

+// Copyright (c) 2009 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.
+
+#include "chrome/common/extensions/extension_resource.h"
+
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/string_util.h"
+#include "chrome/browser/extensions/extension_l10n_util.h"
+#include "googleurl/src/gurl.h"
+#include "net/base/net_util.h"
+
+ExtensionResource::ExtensionResource() {
+}
+
+ExtensionResource::ExtensionResource(const FilePath& extension_root,
+                                     const FilePath& relative_path)
+    : extension_root_(extension_root),
+      relative_path_(relative_path) {
+}
+
+const FilePath& ExtensionResource::GetFilePath() const {
+  if (extension_root_.empty() || relative_path_.empty())
+    return full_resource_path_;
+
+  // We've already checked, just return last value.
+  if (!full_resource_path_.empty())
+    return full_resource_path_;
+
+  // Stat l10n file, and return new path if it exists.
+  FilePath l10n_relative_path =
+    extension_l10n_util::GetL10nRelativePath(relative_path_);
+  full_resource_path_ = CombinePathsSafely(extension_root_, l10n_relative_path);
+  if (file_util::PathExists(full_resource_path_)) {
+    return full_resource_path_;
+  }
+
+  // Fall back to root resource.
+  full_resource_path_ = CombinePathsSafely(extension_root_, relative_path_);
+  return full_resource_path_;
+}
+
+FilePath ExtensionResource::CombinePathsSafely(
+    const FilePath& extension_path,
+    const FilePath& relative_resource_path) const {
+  // Build up a file:// URL and convert that back to a FilePath.  This avoids
+  // URL encoding and path separator issues.
+
+  // Convert the extension's root to a file:// URL.
+  GURL extension_url = net::FilePathToFileURL(extension_path);
+  if (!extension_url.is_valid())
+    return FilePath();
+
+  // Append the requested path.
+  std::string relative_path =
+    WideToUTF8(relative_resource_path.ToWStringHack());
+  GURL::Replacements replacements;
+  std::string new_path(extension_url.path());
+  new_path += "/";
+  new_path += relative_path;
+  replacements.SetPathStr(new_path);
+  GURL file_url = extension_url.ReplaceComponents(replacements);
+  if (!file_url.is_valid())
+    return FilePath();
+
+  // Convert the result back to a FilePath.
+  FilePath ret_val;
+  if (!net::FileURLToFilePath(file_url, &ret_val))
+    return FilePath();
+
+  // Double-check that the path we ended up with is actually inside the
+  // extension root.
+  if (!extension_path.IsParent(ret_val))
+    return FilePath();
+
+  return ret_val;
+}
+
+// Unittesting helpers.
+FilePath::StringType ExtensionResource::NormalizeSeperators(
+    FilePath::StringType path) const {
+#if defined(FILE_PATH_USES_WIN_SEPARATORS)
+  FilePath::StringType ret_val;
+  for (size_t i = 0; i < path.length(); i++) {
+    if (FilePath::IsSeparator(path[i]))
+      path[i] = FilePath::kSeparators[0];
+  }
+#endif  // FILE_PATH_USES_WIN_SEPARATORS
+  return path;
+}
+
+bool ExtensionResource::ComparePathWithDefault(const FilePath& path) const {
+  if (NormalizeSeperators(path.value()) ==
+    NormalizeSeperators(full_resource_path_.value())) {
+    return true;
+  } else {
+    return false;
+  }
+}