Add single line of tips to NNTP.

BUG= http://crbug.com/19162
TEST= Start browser with NNTP, note line of tips at bottom.

Review URL: http://codereview.chromium.org/173087

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@24384 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 202 insertions, 122 deletions

diff --git a/chrome/browser/browser_theme_provider.cc b/chrome/browser/browser_theme_provider.cc
index 0b43fa3..3a7dc92 100644
--- a/chrome/browser/browser_theme_provider.cc
+++ b/chrome/browser/browser_theme_provider.cc
@@ -116,7 +116,7 @@ const SkColor BrowserThemeProvider::kDefaultColorNTPSection =
 const SkColor BrowserThemeProvider::kDefaultColorNTPSectionText =
     SkColorSetRGB(0, 0, 0);
 const SkColor BrowserThemeProvider::kDefaultColorNTPSectionLink =
-    SkColorSetRGB(16, 50, 105);
+    SkColorSetRGB(0, 0, 204);
 const SkColor BrowserThemeProvider::kDefaultColorControlBackground = NULL;
 const SkColor BrowserThemeProvider::kDefaultColorButtonBackground = NULL;
 
diff --git a/chrome/browser/dom_ui/tips_handler.cc b/chrome/browser/dom_ui/tips_handler.cc
index c495a0d..4690c27 100644
--- a/chrome/browser/dom_ui/tips_handler.cc
+++ b/chrome/browser/dom_ui/tips_handler.cc
@@ -12,19 +12,10 @@
 #include "chrome/common/url_constants.h"
 #include "googleurl/src/gurl.h"
 
-namespace {
-
-  // TODO(mrc): l10n
-  // This title should only appear the very first time Chrome is run with
-  // web resources enabled; otherwise the cache should be populated.
-  static const wchar_t* kTipsTitleAtStartup =
-      L"Tips and recommendations to help you discover interesting websites.";
-}
-
 DOMMessageHandler* TipsHandler::Attach(DOMUI* dom_ui) {
   dom_ui_ = dom_ui;
   tips_cache_ = dom_ui_->GetProfile()->GetPrefs()->
-      GetDictionary(prefs::kNTPTipsCache);
+      GetMutableDictionary(prefs::kNTPTipsCache);
   return DOMMessageHandler::Attach(dom_ui);
 }
 
@@ -38,36 +29,26 @@ void TipsHandler::HandleGetTips(const Value* content) {
   ListValue list_value;
 
   // Holds the web resource data found in the preferences cache.
-  DictionaryValue* wr_dict;
+  ListValue* wr_list;
 
-  // These values hold the data for each web resource item.  As the web
-  // resource server solidifies, these may change.
-  std::wstring title;
-  std::wstring thumb;
-  std::wstring source;
-  std::wstring snipp;
-  std::wstring url;
+  // These values hold the data for each web resource item.
+  int current_tip_index;
+  std::string current_tip;
 
-  // This should only be true on the very first Chrome run; otherwise,
-  // the cache should be populated.
-  if (tips_cache_ == NULL || tips_cache_->GetSize() < 1) {
-    title = kTipsTitleAtStartup;
-    DictionaryValue* tip_dict = new DictionaryValue();
-    tip_dict->SetString(WebResourceService::kWebResourceTitle, title);
-    tip_dict->SetString(WebResourceService::kWebResourceURL, L"");
-    list_value.Append(tip_dict);
-  } else {
-    int tip_counter = 0;
-    while (tips_cache_->GetDictionary(IntToWString(tip_counter++), &wr_dict)) {
-      if (wr_dict &&
-          wr_dict->GetSize() > 0 &&
-          wr_dict->GetString(WebResourceService::kWebResourceTitle, &title) &&
-          wr_dict->GetString(WebResourceService::kWebResourceURL, &url) &&
-          IsValidURL(url)) {
+  if (tips_cache_ != NULL && tips_cache_->GetSize() >= 0) {
+    if (tips_cache_->GetInteger(
+        WebResourceService::kCurrentTipPrefName, &current_tip_index) &&
+        tips_cache_->GetList(
+        WebResourceService::kTipCachePrefName, &wr_list)) {
+      if (wr_list && wr_list->GetSize() > 0)
+      if (wr_list->GetSize() <= static_cast<size_t>(current_tip_index))
+        current_tip_index = 0;
+      if (wr_list->GetString(current_tip_index, &current_tip)) {
         DictionaryValue* tip_dict = new DictionaryValue();
-        tip_dict->SetString(WebResourceService::kWebResourceTitle, title);
-        tip_dict->SetString(WebResourceService::kWebResourceURL, url);
+        tip_dict->SetString(L"tip_html_text", current_tip);
         list_value.Append(tip_dict);
+        tips_cache_->SetInteger(WebResourceService::kCurrentTipPrefName,
+                                current_tip_index + 1);
       }
     }
   }
diff --git a/chrome/browser/dom_ui/tips_handler.h b/chrome/browser/dom_ui/tips_handler.h
index e5afe38..a5915ec 100644
--- a/chrome/browser/dom_ui/tips_handler.h
+++ b/chrome/browser/dom_ui/tips_handler.h
@@ -6,16 +6,6 @@
 // has been stored in the user's preferences file.  Used mainly
 // by the suggestions and tips area of the new tab page.
 
-// Current sketch of tip cache format, hardcoded for popgadget data in
-// basic text form:
-
-// "tip_cache": {
-//    "0": {
-//        "title": text giving title of item
-//        "url": link to item's page
-//    },
-//    [up to number of items in kMaxWebResourceCacheSize]
-
 #ifndef CHROME_BROWSER_DOM_UI_TIPS_HANDLER_H_
 #define CHROME_BROWSER_DOM_UI_TIPS_HANDLER_H_
 
@@ -49,7 +39,7 @@ class TipsHandler : public DOMMessageHandler {
   DOMUI* dom_ui_;
 
   // Filled with data from cache in preferences.
-  const DictionaryValue* tips_cache_;
+  DictionaryValue* tips_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(TipsHandler);
 };
diff --git a/chrome/browser/resources/new_new_tab.css b/chrome/browser/resources/new_new_tab.css
index c2ce487..a2af6fb0 100644
--- a/chrome/browser/resources/new_new_tab.css
+++ b/chrome/browser/resources/new_new_tab.css
@@ -682,6 +682,13 @@ html[dir='rtl'] #t4 {
   top: 183px;
 }
 
+/* tip line */
+#tip-line {
+  margin-top: 40px;
+  margin-bottom: 10px;
+  text-align: center;
+}
+
 /* small */
 
 @media (max-width: 920px) {
diff --git a/chrome/browser/resources/new_new_tab.html b/chrome/browser/resources/new_new_tab.html
index 9415d16..5266a88 100644
--- a/chrome/browser/resources/new_new_tab.html
+++ b/chrome/browser/resources/new_new_tab.html
@@ -35,11 +35,13 @@ function registerCallback(name) {
 chrome.send('getShownSections');
 chrome.send('getMostVisited');
 chrome.send('getRecentlyClosedTabs');
+chrome.send('getTips');
 
 registerCallback('onShownSections');
 registerCallback('mostVisitedPages');
 registerCallback('recentlyClosedTabs');
 registerCallback('syncMessageChanged');
+registerCallback('tips');
 
 logEvent('log start');
 
@@ -223,6 +225,9 @@ document.write('<link id="themecss" rel="stylesheet" ' +
     <span><a href="">&nbsp;</a></span>
   </div>
 
+  <div id="tip-line">
+  </div>
+
   <div id="attribution" class="attribution">
     <span i18n-content="attributionintro"></span><br />
     <img id="attribution-img" />
diff --git a/chrome/browser/resources/new_new_tab.js b/chrome/browser/resources/new_new_tab.js
index 78f7912..e9618a9 100644
--- a/chrome/browser/resources/new_new_tab.js
+++ b/chrome/browser/resources/new_new_tab.js
@@ -94,6 +94,31 @@ function mostVisitedPages(data, firstRun) {
   }
 }
 
+var tipCache = {};
+
+function tips(data) {
+  logEvent('received tips');
+  tipCache = data;
+  renderTip();
+}
+
+function createTip(data) {
+  var parsedTips;
+  try {
+    parsedTips = parseHtmlSubset(data[0].tip_html_text);
+  } catch (parseErr) {
+    console.log('Error parsing tips: ' + parseErr.message);
+  }
+  return parsedTips;
+}
+
+function renderTip() {
+  var tipElement = $('tip-line');
+  // There should always be only one tip.
+  tipElement.textContent = '';
+  tipElement.appendChild(createTip(tipCache));
+}
+
 function recentlyClosedTabs(data) {
   logEvent('received recently closed tabs');
   // We need to store the recent items so we can update the layout on a resize.
@@ -1539,3 +1564,76 @@ var dnd = {
 };
 
 dnd.init();
+
+/**
+ * Whitelist of tag names allowed in parseHtmlSubset.
+ * @type {[string]}
+ * /
+var allowedTags = ['A', 'B', 'STRONG'];
+
+/**
+ * Parse a very small subset of HTML.
+ * @param {string} s The string to parse.
+ * @throws {Error} In case of non supported markup.
+ * @return {DocumentFragment} A document fragment containing the DOM tree.
+ */
+var allowedAttributes = {
+  'href': function(node, value) {
+    // Only allow a[href] starting with http:// and https://
+    return node.tagName == 'A' && (value.indexOf('http://') == 0 ||
+        value.indexOf('https://') == 0);
+  }
+}
+
+/**
+ * Parse a very small subset of HTML.  This ensures that insecure HTML /
+ * javascript cannot be injected into the new tab page.
+ * @param {string} s The string to parse.
+ * @throws {Error} In case of non supported markup.
+ * @return {DocumentFragment} A document fragment containing the DOM tree.
+ */
+function parseHtmlSubset(s) {
+  function walk(n, f) {
+    f(n);
+    for (var i = 0; i < n.childNodes.length; i++) {
+      walk(n.childNodes[i], f);
+    }
+  }
+
+  function assertElement(node) {
+    if (allowedTags.indexOf(node.tagName) == -1)
+      throw Error(node.tagName + ' is not supported');
+  }
+
+  function assertAttribute(attrNode, node) {
+    var n = attrNode.nodeName;
+    var v = attrNode.nodeValue;
+    if (!allowedAttributes.hasOwnProperty(n) || !allowedAttributes[n](node, v))
+      throw Error(node.tagName + '[' + n + '="' + v + '"] is not supported');
+  }
+
+  var r = document.createRange();
+  r.selectNode(document.body);
+  // This does not execute any scripts.
+  var df = r.createContextualFragment(s);
+  walk(df, function(node) {
+    switch (node.nodeType) {
+      case Node.ELEMENT_NODE:
+        assertElement(node);
+        var attrs = node.attributes;
+        for (var i = 0; i < attrs.length; i++) {
+          assertAttribute(attrs[i], node);
+        }
+        break;
+
+      case Node.COMMENT_NODE:
+      case Node.DOCUMENT_FRAGMENT_NODE:
+      case Node.TEXT_NODE:
+        break;
+
+      default:
+        throw Error('Node type ' + node.nodeType + ' is not supported');
+    }
+  });
+  return df;
+}
diff --git a/chrome/browser/resources/new_tab_theme.css b/chrome/browser/resources/new_tab_theme.css
index b59ef62c..e4547cd 100644
--- a/chrome/browser/resources/new_tab_theme.css
+++ b/chrome/browser/resources/new_tab_theme.css
@@ -56,7 +56,8 @@ body {
 }
 #recently-closed span,
 #recently-closed a,
-#recently-closed a:link {
+#recently-closed a:link,
+#tip-line a {
   color: $$4; /* COLOR_NTP_SECTION_LINK */
   text-decoration:underline;
 }
@@ -66,3 +67,7 @@ body {
   color: $9;
   text-align:right;
 }
+
+#tip-line {
+  color: $$8;
+}
diff --git a/chrome/browser/utility_process_host.h b/chrome/browser/utility_process_host.h
index c52c424..fa0a63c 100644
--- a/chrome/browser/utility_process_host.h
+++ b/chrome/browser/utility_process_host.h
@@ -48,7 +48,7 @@ class UtilityProcessHost : public ChildProcessHost {
     // contains the parsed list of web resource items downloaded from the
     // web resource server.
     virtual void OnUnpackWebResourceSucceeded(
-        const ListValue& json_data) {}
+        const DictionaryValue& json_data) {}
 
     // Called when an error occurred while parsing the resource data.
     // |error_message| contains a description of the problem.
diff --git a/chrome/browser/web_resource/web_resource_service.cc b/chrome/browser/web_resource/web_resource_service.cc
index 5692fdb..f88b95d 100644
--- a/chrome/browser/web_resource/web_resource_service.cc
+++ b/chrome/browser/web_resource/web_resource_service.cc
@@ -15,8 +15,8 @@
 #include "net/base/load_flags.h"
 #include "net/url_request/url_request_status.h"
 
-const wchar_t* WebResourceService::kWebResourceTitle = L"title";
-const wchar_t* WebResourceService::kWebResourceURL = L"url";
+const wchar_t* WebResourceService::kCurrentTipPrefName = L"current_tip";
+const wchar_t* WebResourceService::kTipCachePrefName = L"tips";
 
 class WebResourceService::WebResourceFetcher
     : public URLFetcher::Delegate {
@@ -130,7 +130,8 @@ class WebResourceService::UnpackerClient
         "Chrome crashed while trying to retrieve web resources.");
   }
 
-  virtual void OnUnpackWebResourceSucceeded(const ListValue& parsed_json) {
+  virtual void OnUnpackWebResourceSucceeded(
+      const DictionaryValue& parsed_json) {
     web_resource_service_->OnWebResourceUnpacked(parsed_json);
     Cleanup();
   }
@@ -167,9 +168,15 @@ class WebResourceService::UnpackerClient
   bool got_response_;
 };
 
-// TODO(mrc): make into a changeable preference.
+// TODO(mirandac): replace these servers tomorrow!
 const wchar_t* WebResourceService::kDefaultResourceServer =
-    L"http://www.google.com/labs/popgadget/world?view=json";
+#if defined(OS_MACOSX)
+  L"https://clients2.google.com/tools/service/npredir?r=chrometips_mac&hl=";
+#elif defined(OS_LINUX)
+  L"https://clients2.google.com/tools/service/npredir?r=chrometips_linux&hl=";
+#else
+  L"https://clients2.google.com/tools/service/npredir?r=chrometips_win&hl=";
+#endif
 
 const char* WebResourceService::kResourceDirectoryName =
     "Resources";
@@ -189,65 +196,57 @@ void WebResourceService::Init() {
   resource_dispatcher_host_ = g_browser_process->resource_dispatcher_host();
   web_resource_fetcher_ = new WebResourceFetcher(this);
   prefs_->RegisterStringPref(prefs::kNTPTipsCacheUpdate, L"0");
-  // TODO(mrc): make sure server name is valid.
-  web_resource_server_ = prefs_->HasPrefPath(prefs::kNTPTipsServer) ?
-      prefs_->GetString(prefs::kNTPTipsServer) :
-      kDefaultResourceServer;
+
+  // TODO(mirandac): allow for language change without wiping out prefs file.
+  if (prefs_->HasPrefPath(prefs::kNTPTipsServer)) {
+    web_resource_server_ = prefs_->GetString(prefs::kNTPTipsServer);
+  } else {
+    web_resource_server_ = kDefaultResourceServer;
+    web_resource_server_.append(
+      ASCIIToWide(g_browser_process->GetApplicationLocale()));
+  }
 }
 
 void WebResourceService::EndFetch() {
   in_fetch_ = false;
 }
 
-void WebResourceService::OnWebResourceUnpacked(const ListValue& parsed_json) {
+void WebResourceService::OnWebResourceUnpacked(
+  const DictionaryValue& parsed_json) {
   // Get dictionary of cached preferences.
   web_resource_cache_ =
       prefs_->GetMutableDictionary(prefs::kNTPTipsCache);
-  ListValue::const_iterator wr_iter = parsed_json.begin();
-  int wr_counter = 0;
-
-  // These values store the data for each new web resource item.
-  std::wstring result_snippet;
-  std::wstring result_url;
-  std::wstring result_source;
-  std::wstring result_title;
-  std::wstring result_title_type;
-  std::wstring result_thumbnail;
-
-  // Iterate through newly parsed preferences, replacing stale cache with
-  // new data.
-  // TODO(mrc): make this smarter, so it actually only replaces stale data,
-  // instead of overwriting the whole thing every time.
-  while (wr_iter != parsed_json.end() &&
-         wr_counter < kMaxResourceCacheSize) {
-    // Each item is stored in the form of a dictionary.
-    // See tips_handler.h for format (this will change until
-    // tip services are solidified!).
-    if (!(*wr_iter)->IsType(Value::TYPE_DICTIONARY))
-      continue;
-    DictionaryValue* wr_dict =
-        static_cast<DictionaryValue*>(*wr_iter);
-
-    // Get next space for resource in prefs file.
-    Value* current_wr;
-    std::wstring wr_counter_str = IntToWString(wr_counter);
-    // Create space if it doesn't exist yet.
-    if (!web_resource_cache_->Get(wr_counter_str, &current_wr) ||
-      !current_wr->IsType(Value::TYPE_DICTIONARY)) {
-        current_wr = new DictionaryValue();
-        web_resource_cache_->Set(wr_counter_str, current_wr);
-    }
-    DictionaryValue* wr_cache_dict =
-      static_cast<DictionaryValue*>(current_wr);
 
-    // Update the resource cache.
-    if (wr_dict->GetString(kWebResourceURL, &result_url))
-      wr_cache_dict->SetString(kWebResourceURL, result_url);
-    if (wr_dict->GetString(kWebResourceTitle, &result_title))
-      wr_cache_dict->SetString(kWebResourceTitle, result_title);
-
-    wr_counter++;
-    wr_iter++;
+  // The list of individual tips.
+  ListValue* tip_holder = new ListValue();
+  web_resource_cache_->Set(WebResourceService::kTipCachePrefName, tip_holder);
+
+  DictionaryValue* topic_dict;
+  ListValue* answer_list;
+  std::wstring topic_id;
+  std::wstring inproduct;
+  int tip_counter = 0;
+
+  if (parsed_json.GetDictionary(L"topic", &topic_dict)) {
+    if (topic_dict->GetString(L"topic_id", &topic_id))
+      web_resource_cache_->SetString(L"topic_id", topic_id);
+    if (topic_dict->GetList(L"answers", &answer_list)) {
+      for (ListValue::const_iterator tip_iter = answer_list->begin();
+           tip_iter != answer_list->end(); ++tip_iter) {
+        if (!(*tip_iter)->IsType(Value::TYPE_DICTIONARY))
+          continue;
+        DictionaryValue* a_dic =
+            static_cast<DictionaryValue*>(*tip_iter);
+        if (a_dic->GetString(L"inproduct", &inproduct)) {
+          tip_holder->Append(Value::CreateStringValue(inproduct));
+        }
+        tip_counter++;
+      }
+      // If we have tips, set current tip to zero.
+      if (!inproduct.empty())
+        web_resource_cache_->SetInteger(
+          WebResourceService::kCurrentTipPrefName, 0);
+    }
   }
   EndFetch();
 }
diff --git a/chrome/browser/web_resource/web_resource_service.h b/chrome/browser/web_resource/web_resource_service.h
index dac392f..caf9d90 100644
--- a/chrome/browser/web_resource/web_resource_service.h
+++ b/chrome/browser/web_resource/web_resource_service.h
@@ -28,16 +28,11 @@ class WebResourceService
   // the process that will parse the JSON, and then update the cache.
   void UpdateResourceCache(const std::string& json_data);
 
-  // Right now, these values correspond to data pulled from the popgadget
-  // JSON feed.  Once we have decided on the final format for the
-  // web resources servers, these will probably change.
-  static const wchar_t* kWebResourceTitle;
-  static const wchar_t* kWebResourceURL;
+  static const wchar_t* kTipDictionaryPrefName;
+  static const wchar_t* kCurrentTipPrefName;
+  static const wchar_t* kTipCachePrefName;
 
   // Default server from which to gather resources.
-  // For now, hard-coded to test JSON data hosted on chromium.org.
-  // Starting 6/22, poptart server will be ready to host data.
-  // Future: more servers and different kinds of data will be served.
   static const wchar_t* kDefaultResourceServer;
 
  private:
@@ -52,7 +47,7 @@ class WebResourceService
   void EndFetch();
 
   // Puts parsed json data in the right places, and writes to prefs file.
-  void OnWebResourceUnpacked(const ListValue& parsed_json);
+  void OnWebResourceUnpacked(const DictionaryValue& parsed_json);
 
   // We need to be able to load parsed resource data into preferences file,
   // and get proper install directory.
@@ -85,8 +80,8 @@ class WebResourceService
   // Delay on first fetch so we don't interfere with startup.
   static const int kStartResourceFetchDelay = 5000;
 
-  // Delay between calls to update the cache (4 hours).
-  static const int kCacheUpdateDelay = 4 * 60 * 60 * 1000;
+  // Delay between calls to update the cache (48 hours).
+  static const int kCacheUpdateDelay = 48 * 60 * 60 * 1000;
 
   // Name of directory inside the profile where we will store resource-related
   // data (for now, thumbnail images).
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 29490f6..f3796a2 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -561,7 +561,7 @@ const wchar_t kNTPTipsCache[] = L"ntp.tips_cache";
 const wchar_t kNTPTipsCacheUpdate[] = L"ntp.tips_cache_update";
 
 // Last server used to fill tips_cache.
-const wchar_t kNTPTipsServer[] = L"ntp.web_resource_server";
+const wchar_t kNTPTipsServer[] = L"ntp.tips_server";
 
 // Which sections should be visible on the new tab page
 // 1 - Show the most visited sites in a grid
diff --git a/chrome/common/render_messages_internal.h b/chrome/common/render_messages_internal.h
index 891dbb7..83f2c62 100644
--- a/chrome/common/render_messages_internal.h
+++ b/chrome/common/render_messages_internal.h
@@ -1653,7 +1653,7 @@ IPC_BEGIN_MESSAGES(ViewHost)
   // Reply when the utility process is done unpacking and parsing JSON data
   // from a web resource.
   IPC_MESSAGE_CONTROL1(UtilityHostMsg_UnpackWebResource_Succeeded,
-                       ListValue /* json data */)
+                       DictionaryValue /* json data */)
 
   // Reply when the utility process has failed while unpacking and parsing a
   // web resource.  |error_message| is a user-readable explanation of what
diff --git a/chrome/common/web_resource/web_resource_unpacker.cc b/chrome/common/web_resource/web_resource_unpacker.cc
index a821547..7f0ced4 100644
--- a/chrome/common/web_resource/web_resource_unpacker.cc
+++ b/chrome/common/web_resource/web_resource_unpacker.cc
@@ -25,11 +25,11 @@ bool WebResourceUnpacker::Run() {
       error_message_ = kInvalidDataTypeError;
       return false;
     }
-    if (!value->IsType(Value::TYPE_LIST)) {
+    if (!value->IsType(Value::TYPE_DICTIONARY)) {
       error_message_ = kUnexpectedJSONFormatError;
       return false;
     }
-    parsed_json_.reset(static_cast<ListValue*>(value.release()));
+    parsed_json_.reset(static_cast<DictionaryValue*>(value.release()));
     return true;
   }
   error_message_ = kInvalidDataTypeError;
diff --git a/chrome/common/web_resource/web_resource_unpacker.h b/chrome/common/web_resource/web_resource_unpacker.h
index 194e1c5..95600f9 100644
--- a/chrome/common/web_resource/web_resource_unpacker.h
+++ b/chrome/common/web_resource/web_resource_unpacker.h
@@ -17,7 +17,7 @@
 #include "base/file_path.h"
 #include "base/scoped_ptr.h"
 
-class ListValue;
+class DictionaryValue;
 
 class WebResourceUnpacker {
  public:
@@ -35,7 +35,7 @@ class WebResourceUnpacker {
   const std::string& error_message() { return error_message_; }
 
   // Gets data which has been parsed by Run().
-  ListValue* parsed_json() {
+  DictionaryValue* parsed_json() {
     return parsed_json_.get();
   }
 
@@ -44,7 +44,7 @@ class WebResourceUnpacker {
   std::string resource_data_;
 
   // Holds the result of JSON parsing of resource_data_.
-  scoped_ptr<ListValue> parsed_json_;
+  scoped_ptr<DictionaryValue> parsed_json_;
 
   // Holds the last error message produced by Run().
   std::string error_message_;