Add ErrorConsole UI for Extension Install Warnings

chrome/browser/ui/webui/extensions/extension_error_handler.cc

+// Copyright 2013 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/browser/ui/webui/extensions/extension_error_handler.h"
+
+#include "base/bind.h"
+#include "base/file_util.h"
+#include "base/files/file_path.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/extensions/extension.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace extensions {
+
+namespace {
+
+// Keys for objects passed to and from extension error UI.
+const char kExtensionIdKey[] = "extensionId";
+const char kPathSuffixKey[] = "pathSuffix";
+const char kErrorMessageKey[] = "errorMessage";
+const char kFileTypeKey[] = "fileType";
+const char kFeatureKey[] = "feature";
+const char kSpecificKey[] = "specific";
+const char kManifestFileType[] = "manifest";
+const char kTitleKey[] = "title";
+const char kBeforeHighlightKey[] = "beforeHighlight";
+const char kHighlightKey[] = "highlight";
+const char kAfterHighlightKey[] = "afterHighlight";
+
+// Populate a DictionaryValue with the highlighted portions for the callback to
+// ExtensionErrorOverlay, given the components.
+void AddHighlightedToDictionaryForOverlay(base::DictionaryValue* dict,
+                                          const std::string& before_highlight,
+                                          const std::string& highlight,
+                                          const std::string& after_highlight) {
+  if (!before_highlight.empty())
+    dict->SetString(kBeforeHighlightKey, base::UTF8ToUTF16(before_highlight));
+  if (!highlight.empty())
+    dict->SetString(kHighlightKey, base::UTF8ToUTF16(highlight));
+  if (!after_highlight.empty())
+    dict->SetString(kAfterHighlightKey, base::UTF8ToUTF16(after_highlight));
+}
+
+// Find the end of a feature in the manifest string. See also
+// FindFeatureBounds().
+// |i| points to the start location of the feature, which is defined as the
+// first character after the name of the feature.
+size_t FindFeatureEnd(const std::string& manifest, size_t i) {
+  size_t levels = 0;
+  bool quoted = false;
+
+  // If the feature is a string, we may need to account for the ending quote.

[Yoyo Zhou, 2013/08/16 00:17:25]

and quoted = true?

[Devlin, 2013/08/16 23:56:54]

Nope.

If we have:
...
"permissions": [ "tabs", "history" ],
...         ^
The index right now will point to the location right after the feature name ends
- in this case, the arrowed quote mark.  We want to skip that one, and not have
quoted = true, because we don't count the other side.

+  if (manifest[i] == '"')
+    ++i;
+
+  char c = manifest[i];
+
+  // We loop until we find the end of a feature. We have found the end of a
+  // feature when we are at the initial level, are not quoted, and have found
+  // a terminating character (a comma or ending bracket). Also be sure to not
+  // run off the end.

[Yoyo Zhou, 2013/08/16 00:17:25]

And do we need to worry about comments? Probably you want to use something like
JSONParser::EatComments beforehand.

[Devlin, 2013/08/16 23:56:54]

This, coupled with a few other edge cases I hadn't thought of, made this larger
(mostly because I wanted to add tests for it). Mind taking another look?
c/b/manifest_highlighter*

+  while (!(levels == 0 && !quoted && (c == ',' || c == '}' || c == ']')) &&
+         i < manifest.size() - 1) {
+    if (!quoted && (c == '{' || c == '['))
+      ++levels;
+    else if (!quoted && (c == '}' || c == ']'))
+      --levels;
+    else if (c == '"')
+      quoted = !quoted;
+    c = manifest[++i];
+  }
+  return i;
+}
+
+// Find the bounds of a feature in the manifest (for highlighting purposes), and
+// populate |start| and |end| accordingly. Return true on success and false on
+// failure.
+// A feature can be at any level in the hierarchy. The "start" of a feature is
+// the first character of the feature name, or the beginning quote of the name,
+// if present.  The "end" of a feature is wherever the next item at the same
+// level starts.
+// For instance, the bounds for the 'permissions' feature at the top level could
+// be '"permissions": { "tabs", "history", "downloads" }', but the feature for
+// 'tabs' within 'permissions' would just be '"tabs"'.
+// We can't use JSON to do this, because we want to display the actual manifest,
+// and once we parse it into JSON, we lose any formatting the user may have had.
+//
+// |manifest| is the string containing the manifest content.
+// |feature| is the name of the feature we are searching for.
+// |enforce_at_top_level| means that the feature is guaranteed to be at the top
+//     level of the manifest (relative to |start|), so we can (and should) skip
+//     any nested occurrences. This is useful in case, e.g., we are looking for
+//     the "permissions" feature, and the manifest also includes a "permissions"
+//     resource file.
+// |start| can point to a location at which we start our search, and will be

[Yoyo Zhou, 2013/08/16 00:17:25]

This "can" phrasing is confusing. How about: |start| contains a location at
which...

[Devlin, 2013/08/16 23:56:54]

Done.

+//     populated with the start of the feature.
+// |end| can point to a location which we should not pass, and will be populated

[Yoyo Zhou, 2013/08/16 00:17:25]

|end| contains a location we should not pass for the beginning of the feature...
(FindFeatureEnd ignores *end)

[Devlin, 2013/08/16 23:56:54]

Done.

+//     with the end of the feature.
+bool FindFeatureBounds(const std::string& manifest,
+                       const std::string& feature,
+                       bool enforce_at_top_level,
+                       size_t* start,
+                       size_t* end) {
+  for (size_t i = *start;
+       i < *end && i < manifest.size() && i != std::string::npos; ++i) {

[Yoyo Zhou, 2013/08/16 00:17:25]

What's the npos check for?

[Devlin, 2013/08/16 23:56:54]

Yeah, I suppose that it's redundant with checking that it's less than size,
since npos is guaranteed to be huge. Taken out.

+    if (manifest.substr(i, feature.size()) == feature) {
+      if (manifest[i - 1] == '"')
+        *start = i - 1;  // include the quote at the beginning of the feature.
+
+      *end = FindFeatureEnd(manifest, i + feature.size());
+      return true;
+    } else if (manifest[i] == '{' && enforce_at_top_level) {
+      i = manifest.find('}', i);
+    } else if (manifest[i] == '[' && enforce_at_top_level) {
+      i = manifest.find(']', i);
+    }
+  }
+  return false;
+}
+
+}  // namespace
+
+ExtensionErrorHandler::ExtensionErrorHandler(Profile* profile)
+    : profile_(profile) {
+}
+
+ExtensionErrorHandler::~ExtensionErrorHandler() {
+}
+
+void ExtensionErrorHandler::GetLocalizedValues(
+    content::WebUIDataSource* source) {
+  source->AddString(
+      "extensionErrorsManifestErrors",
+      l10n_util::GetStringUTF16(IDS_EXTENSIONS_ERRORS_MANIFEST_ERRORS));
+  source->AddString(
+      "extensionErrorsShowMore",
+      l10n_util::GetStringUTF16(IDS_EXTENSIONS_ERRORS_SHOW_MORE));
+  source->AddString(
+      "extensionErrorsShowFewer",
+      l10n_util::GetStringUTF16(IDS_EXTENSIONS_ERRORS_SHOW_FEWER));
+  source->AddString(
+      "extensionErrorViewSource",
+      l10n_util::GetStringUTF16(IDS_EXTENSIONS_ERROR_VIEW_SOURCE));
+}
+
+void ExtensionErrorHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback(
+      "extensionErrorRequestFileSource",
+      base::Bind(&ExtensionErrorHandler::HandleRequestFileSource,
+                 base::Unretained(this)));
+}
+
+void ExtensionErrorHandler::HandleRequestFileSource(
+    const base::ListValue* args) {
+  // There should only be one argument, a dictionary. Use this instead of a list
+  // because it's more descriptive, harder to accidentally break with minor
+  // modifications, and supports optional arguments more easily.
+  CHECK(args->GetSize() == 1);
+
+  const base::DictionaryValue* dict = NULL;
+
+  // Four required arguments: extension_id, path_suffix, error_message, and
+  // file_type.
+  std::string extension_id;
+  base::FilePath::StringType path_suffix;
+  base::string16 error_message;
+  std::string file_type;
+
+  if (!args->GetDictionary(0, &dict) ||
+      !dict->GetString(kExtensionIdKey, &extension_id) ||
+      !dict->GetString(kPathSuffixKey, &path_suffix) ||
+      !dict->GetString(kErrorMessageKey, &error_message) ||
+      !dict->GetString(kFileTypeKey, &file_type)) {
+    NOTREACHED();
+    return;
+  }
+
+  const Extension* extension =
+      ExtensionSystem::Get(Profile::FromWebUI(web_ui()))->
+      extension_service()->GetExtensionById(extension_id,
+                                            true /* include disabled */ );
+  base::FilePath path = extension->path().Append(path_suffix);
+
+  // Setting the title and the error message is the same for all file types.
+  scoped_ptr<base::DictionaryValue> results(new base::DictionaryValue);
+  results->SetString(kTitleKey,
+                     base::UTF8ToUTF16(extension->name()) +
+                         base::ASCIIToUTF16(": ") +
+                         path.BaseName().LossyDisplayName());
+  results->SetString(kErrorMessageKey, error_message);
+
+  base::Closure closure;
+  std::string* contents = NULL;
+
+  if (file_type == kManifestFileType) {
+    std::string feature;
+    std::string specific;
+    if (!dict->GetString(kFeatureKey, &feature)) {
+      NOTREACHED();
+      return;
+    }
+    // A "specific" location is optional.
+    dict->GetString(kSpecificKey, &specific);
+
+    contents = new std::string;  // Owned by GetManifestFileCallback()
+    closure = base::Bind(&ExtensionErrorHandler::GetManifestFileCallback,
+                         base::Unretained(this),
+                         base::Owned(results.release()),
+                         feature,
+                         specific,
+                         base::Owned(contents));
+  } else {  // currently, only manifest file types supported.
+    NOTREACHED();
+    return;
+  }
+
+  content::BrowserThread::PostBlockingPoolTaskAndReply(
+      FROM_HERE,
+      base::Bind(base::IgnoreResult(&file_util::ReadFileToString),
+                 path,
+                 contents),
+      closure);
+}
+
+void ExtensionErrorHandler::GetManifestFileCallback(
+    base::DictionaryValue* results,
+    const std::string& key,
+    const std::string& specific,
+    std::string* contents) {
+  // We initially start at the opening of the manifest dictionary, and end at
+  // it's termination.
+  size_t feature_start = contents->find('{');
+  size_t feature_end = contents->rfind('}');
+
+  // Find the bounds of the feature in order to highlight them.
+  FindFeatureBounds(*contents, key, true, &feature_start, &feature_end);
+
+  // If we were given a specific location in the feature, find it to highlight.
+  if (!specific.empty())
+    FindFeatureBounds(*contents, specific, false, &feature_start, &feature_end);
+
+  // We may have found trailing whitespace. Don't use base::TrimWhitespace,
+  // because we want to keep any whitespace we find - just not highlight it.
+  size_t trim = contents->find_last_not_of(" \t\n\r", feature_end - 1);
+  if (trim < feature_end && trim > feature_start)
+    feature_end = trim + 1;
+
+  // Break contents into three sections - unhighlighted before, highlighted, and
+  // unhighlighted after. The highlighted portion should be the feature (or
+  // specific portion of the feature).
+  // If we never found bounds for the feature, then there will be no highlighted
+  // portion.
+  AddHighlightedToDictionaryForOverlay(
+      results,
+      contents->substr(0, feature_start),  // before highlight
+      contents->substr(feature_start,
+                       feature_end - feature_start),  // highlight
+      contents->substr(feature_end) /* after highlight */ );
+
+  web_ui()->CallJavascriptFunction(
+      "ExtensionErrorOverlay.requestFileSourceResponse", *results);
+}
+
+}  // namespace extensions