Add support for distilling arbitrary URLs in DOM Distiller Viewer.

components/dom_distiller/content/dom_distiller_viewer_source.cc

 // Copyright 2014 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 "components/dom_distiller/content/dom_distiller_viewer_source.h"
 
 #include <sstream>
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "components/dom_distiller/core/dom_distiller_service.h"
 #include "components/dom_distiller/core/proto/distilled_article.pb.h"
 #include "components/dom_distiller/core/proto/distilled_page.pb.h"
 #include "components/dom_distiller/core/task_tracker.h"
+#include "components/dom_distiller/core/url_constants.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "grit/component_resources.h"
 #include "grit/component_strings.h"
 #include "net/base/escape.h"
+#include "net/base/url_util.h"
 #include "net/url_request/url_request.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "url/gurl.h"
 
+namespace dom_distiller {
+
 namespace {
 
-const char kCssPath[] = "readability.css";
+const char kInternalScheme[] = "chrome-distiller-internal";
 
 std::string ReplaceHtmlTemplateValues(std::string title, std::string content) {
   base::StringPiece html_template =
       ResourceBundle::GetSharedInstance().GetRawDataResource(
           IDR_DOM_DISTILLER_VIEWER_HTML);
   std::vector<std::string> substitutions;
   substitutions.push_back(title);     // $1
   substitutions.push_back(kCssPath);  // $2
   substitutions.push_back(title);     // $3
   substitutions.push_back(content);   // $4
   return ReplaceStringPlaceholders(html_template, substitutions, NULL);
 }
 
 }  // namespace
 
-namespace dom_distiller {
-
 // Handles receiving data asynchronously for a specific entry, and passing
 // it along to the data callback for the data source.
-class RequestViewerHandle : public ViewRequestDelegate {
+class DomDistillerViewerSource::RequestViewerHandle
+    : public ViewRequestDelegate {
  public:
   explicit RequestViewerHandle(
       const content::URLDataSource::GotDataCallback& callback);
   virtual ~RequestViewerHandle();
 
   // ViewRequestDelegate implementation.
   virtual void OnArticleReady(const DistilledArticleProto* article_proto)
       OVERRIDE;
 
   void TakeViewerHandle(scoped_ptr<ViewerHandle> viewer_handle);
 
  private:
   // The handle to the view request towards the DomDistillerService. It
   // needs to be kept around to ensure the distillation request finishes.
   scoped_ptr<ViewerHandle> viewer_handle_;
 
   // This holds the callback to where the data retrieved is sent back.
   content::URLDataSource::GotDataCallback callback_;
 };
 
-RequestViewerHandle::RequestViewerHandle(
+DomDistillerViewerSource::RequestViewerHandle::RequestViewerHandle(
     const content::URLDataSource::GotDataCallback& callback)
     : callback_(callback) {}
 
-RequestViewerHandle::~RequestViewerHandle() {}
+DomDistillerViewerSource::RequestViewerHandle::~RequestViewerHandle() {}
 
-void RequestViewerHandle::OnArticleReady(
+void DomDistillerViewerSource::RequestViewerHandle::OnArticleReady(
     const DistilledArticleProto* article_proto) {
   DCHECK(article_proto);
   std::string title;
   std::string unsafe_article_html;
   if (article_proto->has_title() && article_proto->pages_size() > 0 &&
       article_proto->pages(0).has_html()) {
     title = net::EscapeForHTML(article_proto->title());
     // TODO(shashishekhar): Add support for correcting displaying multiple pages
     // after discussing the right way to display them.
     std::ostringstream unsafe_output_stream;
     for (int page_num = 0; page_num < article_proto->pages_size(); ++page_num) {
       unsafe_output_stream << article_proto->pages(page_num).html();
     }
     unsafe_article_html = unsafe_output_stream.str();
   } else {
     title = l10n_util::GetStringUTF8(IDS_DOM_DISTILLER_VIEWER_NO_DATA_TITLE);
     unsafe_article_html =
         l10n_util::GetStringUTF8(IDS_DOM_DISTILLER_VIEWER_NO_DATA_CONTENT);
   }
   std::string unsafe_page_html =
       ReplaceHtmlTemplateValues(title, unsafe_article_html);
   callback_.Run(base::RefCountedString::TakeString(&unsafe_page_html));
   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
 
-void RequestViewerHandle::TakeViewerHandle(
+void DomDistillerViewerSource::RequestViewerHandle::TakeViewerHandle(
     scoped_ptr<ViewerHandle> viewer_handle) {
   viewer_handle_ = viewer_handle.Pass();
 }
 
 DomDistillerViewerSource::DomDistillerViewerSource(
-    DomDistillerService* dom_distiller_service,
+    DomDistillerServiceInterface* dom_distiller_service,
     const std::string& scheme)
     : scheme_(scheme), dom_distiller_service_(dom_distiller_service) {}
 
 DomDistillerViewerSource::~DomDistillerViewerSource() {}
 
 std::string DomDistillerViewerSource::GetSource() const {
   return scheme_ + "://";
 }
 
 void DomDistillerViewerSource::StartDataRequest(
@@ skipping 12 matching lines @@
   if (kCssPath == path) {
     std::string css = ResourceBundle::GetSharedInstance()
                           .GetRawDataResource(IDR_DISTILLER_CSS)
                           .as_string();
     callback.Run(base::RefCountedString::TakeString(&css));
     return;
   }
 
   RequestViewerHandle* request_viewer_handle =
       new RequestViewerHandle(callback);
-  std::string entry_id = StringToUpperASCII(path);
   scoped_ptr<ViewerHandle> viewer_handle =
-      dom_distiller_service_->ViewEntry(request_viewer_handle, entry_id);
+      CreateViewRequest(path, request_viewer_handle);
+
   if (viewer_handle) {
     // The service returned a |ViewerHandle| and guarantees it will call
     // the |RequestViewerHandle|, so passing ownership to it, to ensure the
     // request is not cancelled. The |RequestViewerHandle| will delete itself
     // after receiving the callback.
     request_viewer_handle->TakeViewerHandle(viewer_handle.Pass());
   } else {
     // The service did not return a |ViewerHandle|, which means the
     // |RequestViewerHandle| will never be called, so clean up now.
     delete request_viewer_handle;
 
     std::string title = l10n_util::GetStringUTF8(
         IDS_DOM_DISTILLER_VIEWER_FAILED_TO_FIND_ARTICLE_TITLE);
     std::string content = l10n_util::GetStringUTF8(
         IDS_DOM_DISTILLER_VIEWER_FAILED_TO_FIND_ARTICLE_CONTENT);
     std::string html = ReplaceHtmlTemplateValues(title, content);
     callback.Run(base::RefCountedString::TakeString(&html));
   }
 };
 
-std::string DomDistillerViewerSource::GetMimeType(const std::string& path)
-    const {
+std::string DomDistillerViewerSource::GetMimeType(
+    const std::string& path) const {
   if (path == kCssPath)
     return "text/css";
   return "text/html";
 }
 
 bool DomDistillerViewerSource::ShouldServiceRequest(
     const net::URLRequest* request) const {
   return request->url().SchemeIs(scheme_.c_str());
 }
 
+// TODO(nyquist): Start tracking requests using this method.
 void DomDistillerViewerSource::WillServiceRequest(
     const net::URLRequest* request,
-    std::string* path) const {
-  if (*path != kCssPath) {
-    // Since the full request is not available to StartDataRequest, replace the
-    // path to contain the data needed.
-    *path = request->url().host();
-  }
-};
+    std::string* path) const {};
 
 std::string DomDistillerViewerSource::GetContentSecurityPolicyObjectSrc()
     const {
-  return "object-src 'none'; style-src 'self'";
+  return "object-src 'none'; style-src 'self';";
+}
+
+scoped_ptr<ViewerHandle> DomDistillerViewerSource::CreateViewRequest(
+    const std::string& path,
+    ViewRequestDelegate* view_request_delegate) {
+  std::string entry_id = GetValueForKeyInURLPathQuery(path, kEntryIdKey);
+  bool has_entry_id = !entry_id.empty();
+  entry_id = StringToUpperASCII(entry_id);
+
+  std::string requested_url_str = GetValueForKeyInURLPathQuery(path, kUrlKey);
+  GURL requested_url(requested_url_str);
+  bool has_url = !requested_url_str.empty() && requested_url.is_valid();

[shashi, 2014/02/25 21:48:08]

nit is requested_url.is_valid() sufficient here?
https://code.google.com/p/chromium/codesearch#chromium/src/url/gurl.h&l=68

[nyquist, 2014/02/27 00:07:37]

Done.

+
+  if (has_entry_id && has_url) {
+    // It is invalid to specify a query param for both |kEntryIdKey| and
+    // |kUrlKey|.
+    return scoped_ptr<ViewerHandle>();
+  }
+
+  if (has_entry_id) {
+    return dom_distiller_service_->ViewEntry(view_request_delegate, entry_id)
+        .Pass();
+  } else if (has_url) {
+    return dom_distiller_service_->ViewUrl(view_request_delegate, requested_url)
+        .Pass();
+  }
+
+  // It is invalid to not specify a query param for |kEntryIdKey| or |kUrlKey|.
+  return scoped_ptr<ViewerHandle>();
+}
+
+std::string DomDistillerViewerSource::GetValueForKeyInURLPathQuery(
+    const std::string& path,
+    const std::string& key) {
+  GURL dummy_url(std::string(kInternalScheme) + "://dummy/" + path);

[shashi, 2014/02/25 21:48:08]

It will be nice to have a comment here, that using a dummy url to parse the key,
value in path.

[nyquist, 2014/02/27 00:07:37]

Done. Also moved more of this into the constant, which cleaned up a little bit.

+  std::string value;
+  net::GetValueForKeyInQuery(dummy_url, key, &value);
+  return value;
 }
 
 }  // namespace dom_distiller