First draft of web resource service; fetches data from a JSON feed

and stores it in user prefs, where it can be used by the new tab page.

BUG = http://crbug.com/13363

Review URL: http://codereview.chromium.org/125052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18766 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 168 insertions, 0 deletions

diff --git a/chrome/browser/dom_ui/new_tab_ui.cc b/chrome/browser/dom_ui/new_tab_ui.cc
index 52b0297..e1dd96e 100644
--- a/chrome/browser/dom_ui/new_tab_ui.cc
+++ b/chrome/browser/dom_ui/new_tab_ui.cc
@@ -22,6 +22,7 @@
 #include "chrome/browser/dom_ui/dom_ui_theme_source.h"
 #include "chrome/browser/dom_ui/downloads_dom_handler.h"
 #include "chrome/browser/dom_ui/history_ui.h"
+#include "chrome/browser/dom_ui/web_resource_handler.h"
 #include "chrome/browser/history/page_usage_data.h"
 #include "chrome/browser/metrics/user_metrics.h"
 #include "chrome/browser/profile.h"
@@ -291,6 +292,8 @@ void NewTabHTMLSource::StartDataRequest(const std::string& path,
       l10n_util::GetString(IDS_NEW_TAB_RECENTLY_CLOSED_WINDOW_MULTIPLE));
   localized_strings.SetString(L"attributionintro",
       l10n_util::GetString(IDS_NEW_TAB_ATTRIBUTION_INTRO));
+  localized_strings.SetString(L"resourcecache",
+      l10n_util::GetString(IDS_NEW_TAB_WEB_RESOURCE_CACHE));
 
   SetFontAndTextDirection(&localized_strings);
 
@@ -1380,6 +1383,9 @@ NewTabUI::NewTabUI(TabContents* contents)
       downloads_handler->Init();
     }
 
+    if (EnableWebResources())
+      AddMessageHandler(new WebResourceHandler(this));
+
     AddMessageHandler(new TemplateURLHandler(this));
     AddMessageHandler(new MostVisitedHandler(this));
     AddMessageHandler(new RecentlyBookmarkedHandler(this));
@@ -1435,6 +1441,8 @@ void NewTabUI::Observe(NotificationType type,
 // static
 void NewTabUI::RegisterUserPrefs(PrefService* prefs) {
   MostVisitedHandler::RegisterUserPrefs(prefs);
+  if (NewTabUI::EnableWebResources())
+    WebResourceHandler::RegisterUserPrefs(prefs);
 }
 
 // static
@@ -1442,3 +1450,9 @@ bool NewTabUI::EnableNewNewTabPage() {
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
   return command_line->HasSwitch(switches::kNewNewTabPage);
 }
+
+bool NewTabUI::EnableWebResources() {
+  const CommandLine* command_line = CommandLine::ForCurrentProcess();
+  return command_line->HasSwitch(switches::kWebResources);
+}
+
diff --git a/chrome/browser/dom_ui/new_tab_ui.h b/chrome/browser/dom_ui/new_tab_ui.h
index 6c3a2f1..851dbfa 100644
--- a/chrome/browser/dom_ui/new_tab_ui.h
+++ b/chrome/browser/dom_ui/new_tab_ui.h
@@ -28,6 +28,9 @@ class NewTabUI : public DOMUI,
   // Whether we should use the prototype new tab page.
   static bool EnableNewNewTabPage();
 
+  // Whether we should enable the web resources backend service
+  static bool EnableWebResources();
+
  private:
   void Observe(NotificationType type,
                const NotificationSource& source,
diff --git a/chrome/browser/dom_ui/web_resource_handler.cc b/chrome/browser/dom_ui/web_resource_handler.cc
new file mode 100644
index 0000000..7895da4
--- /dev/null
+++ b/chrome/browser/dom_ui/web_resource_handler.cc
@@ -0,0 +1,95 @@
+// Copyright (c) 2006-2008 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 "base/values.h"
+#include "chrome/browser/dom_ui/web_resource_handler.h"
+#include "chrome/browser/profile.h"
+#include "chrome/browser/web_resource/web_resource_service.h"
+#include "chrome/common/web_resource/web_resource_unpacker.h"
+#include "chrome/common/pref_names.h"
+
+namespace {
+
+  const int kNumWebResourcesToShow = 2;
+
+  // 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* kWebResourceTitleAtStartup =
+      L"New: Suggestion Box!";
+
+  // This snipp should only appear the very first time Chrome is run with
+  // web resources enabled; otherwise the cache should be populated.
+  static const wchar_t* kWebResourceSnippetAtStartup =
+      L"Tips and recommendations to help you discover interesting websites.";
+}
+
+WebResourceHandler::WebResourceHandler(DOMUI* dom_ui)
+    : DOMMessageHandler(dom_ui),
+      dom_ui_(dom_ui) {
+  dom_ui->RegisterMessageCallback("getNextCachedWebResource",
+      NewCallback(this, &WebResourceHandler::HandleGetCachedWebResource));
+
+  web_resource_cache_ = dom_ui_->GetProfile()->GetPrefs()->
+      GetDictionary(prefs::kNTPWebResourceCache);
+}
+
+void WebResourceHandler::HandleGetCachedWebResource(const Value* content) {
+  // Eventually we will feed more than one web resource datum at a time
+  // to the NTP; for now, this is a list containing one item: the tip
+  // to be displayed.
+  ListValue list_value;
+
+  // Holds the web resource data found in the preferences cache.
+  DictionaryValue* wr_dict;
+
+  // Dictionary which will be sent back in a Javascript call.
+  DictionaryValue* tip_dict = new DictionaryValue();
+
+  // 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;
+
+  // This should only be true on the very first Chrome run; otherwise,
+  // the cache should be populated.
+  if (web_resource_cache_ == NULL || web_resource_cache_->GetSize() < 1) {
+    title = kWebResourceTitleAtStartup;
+    snipp = kWebResourceSnippetAtStartup;
+  } else {
+    // Right now, hard-coded to simply get the first item (marked "0") in the
+    // resource data stored in the cache.  Fail silently if data is missing.
+    // TODO(mrc): If data is missing, iterate through cache.
+    web_resource_cache_->GetDictionary(L"0", &wr_dict);
+    if (wr_dict &&
+        wr_dict->GetSize() > 0 &&
+        wr_dict->GetString(WebResourceService::kWebResourceTitle, &title) &&
+        wr_dict->GetString(WebResourceService::kWebResourceThumb, &thumb) &&
+        wr_dict->GetString(WebResourceService::kWebResourceSource, &source) &&
+        wr_dict->GetString(WebResourceService::kWebResourceSnippet, &snipp) &&
+        wr_dict->GetString(WebResourceService::kWebResourceURL, &url)) {
+      tip_dict->SetString(WebResourceService::kWebResourceTitle, title);
+      tip_dict->SetString(WebResourceService::kWebResourceThumb, thumb);
+      tip_dict->SetString(WebResourceService::kWebResourceSource, source);
+      tip_dict->SetString(WebResourceService::kWebResourceSnippet, snipp);
+      tip_dict->SetString(WebResourceService::kWebResourceURL, url);
+    }
+  }
+
+  list_value.Append(tip_dict);
+
+  // Send list of snippets back out to the DOM.
+  dom_ui_->CallJavascriptFunction(L"nextWebResource", list_value);
+}
+
+// static
+void WebResourceHandler::RegisterUserPrefs(PrefService* prefs) {
+  prefs->RegisterDictionaryPref(prefs::kNTPWebResourceCache);
+  prefs->RegisterStringPref(prefs::kNTPWebResourceServer,
+      WebResourceService::kDefaultResourceServer);
+}
+
diff --git a/chrome/browser/dom_ui/web_resource_handler.h b/chrome/browser/dom_ui/web_resource_handler.h
new file mode 100644
index 0000000..01157f9
--- /dev/null
+++ b/chrome/browser/dom_ui/web_resource_handler.h
@@ -0,0 +1,56 @@
+// Copyright (c) 2006-2008 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.
+
+// This class pulls data from a web resource (such as a JSON feed) which
+// 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 poptart data in
+// basic text form:
+
+// "web_resource_cache": {
+//    "0": {
+//        "index": should become time field (or not)
+//        "snippet": the text of the item
+//        "source": text describing source (i.e., "New York Post")
+//        "thumbnail": URL of thumbnail on popgadget server
+//        "title": text giving title of item
+//        "url": link to item's page
+//    },
+//    [up to number of items in kMaxWebResourceCacheSize]
+
+#ifndef CHROME_BROWSER_DOM_UI_WEB_RESOURCE_HANDLER_H_
+#define CHROME_BROWSER_DOM_UI_WEB_RESOURCE_HANDLER_H_
+
+#include "chrome/browser/dom_ui/dom_ui.h"
+
+class DictionaryValue;
+class DOMUI;
+class PrefService;
+class Value;
+
+class WebResourceHandler : public DOMMessageHandler {
+ public:
+  explicit WebResourceHandler(DOMUI* dom_ui);
+
+  WebResourceHandler();
+
+  // Callback which pulls web resource data from the preferences.
+  void HandleGetCachedWebResource(const Value* content);
+
+  // Register web resource cache with pref service.
+  static void RegisterUserPrefs(PrefService* prefs);
+
+ private:
+  // So we can push data out to the page that has called this handler.
+  DOMUI* dom_ui_;
+
+  // Filled with data from cache in preferences.
+  const DictionaryValue* web_resource_cache_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebResourceHandler);
+};
+
+#endif  // CHROME_BROWSER_DOM_UI_WEB_RESOURCE_HANDLER_H_
+