Add link URL and success/failure callback parameters to chrome.webstore.install()

chrome/renderer/extensions/chrome_webstore_bindings.cc

 // Copyright (c) 2011 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/renderer/extensions/chrome_webstore_bindings.h"
 
 #include "base/string_util.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/renderer/extensions/extension_render_view_helper.h"
 #include "content/renderer/render_view.h"
 #include "googleurl/src/gurl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebElement.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebNode.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebNodeList.h"
 #include "v8/include/v8.h"
 
 using WebKit::WebDocument;
 using WebKit::WebElement;
 using WebKit::WebFrame;
 using WebKit::WebNode;
 using WebKit::WebNodeList;
 
+namespace {
+
+const char kWebstoreV8ExtensionName[] = "v8/ChromeWebstore";
+
 const char kWebstoreLinkRelation[] = "chrome-webstore-item";
 
+const char kPreferredStoreLinkUrlNotAString[] =
+    "The Chrome Web Store item link URL parameter must be a string.";
+const char kSuccessCallbackNotAFunctionError[] =
+    "The success callback parameter must be a function.";
+const char kFailureCallbackNotAFunctionError[] =
+    "The failure callback parameter must be a function.";
 const char kNotInTopFrameError[] =
     "Chrome Web Store installations can only be started by the top frame.";
 const char kNotUserGestureError[] =
     "Chrome Web Store installations can only be initated by a user gesture.";
 const char kNoWebstoreItemLinkFoundError[] =
     "No Chrome Web Store item link found.";
 const char kInvalidWebstoreItemUrlError[] =
     "Invalid Chrome Web Store item URL.";
 
-namespace extensions_v8 {
+// chrome.webstore.install() calls generate an install ID so that the install's
+// callbacks may be fired when the browser notifies us of install completion
+// (successful or not) via HandleInstallResponse.
+int next_install_id;
 
-static const char* const kWebstoreExtensionName = "v8/ChromeWebstore";
+// Callbacks are kept track of in maps keyed by install ID. Values are weak
+// references to functions. Entries are automatically removed when functions
+// get garbage collected.
+typedef std::map<int, v8::Persistent<v8::Function> > CallbackMap;
 
-class ChromeWebstoreExtensionWrapper : public v8::Extension {
+CallbackMap success_callbacks;

[Aaron Boodman, 2011/09/06 23:24:32]

Consider making a PendingWebstoreInstall class that contains the success and
failure functions. You could do the MakeWeak() thing in the constructor, so it's
a little more self-documenting. The argument to MakeWeak() could just the class
itself.

[Mihai Parparita -not on Chrome, 2011/09/07 00:05:03]

As discussed, this isn't that straightforward since we're dealing with two
distinct v8 objects that could be GC-ed at different times, so they can't use
the same PendingWebstoreInstall class.

+CallbackMap failure_callbacks;

[Aaron Boodman, 2011/09/06 23:24:32]

Static non-pod variables are not allowed in Chromium. Use base::LazyInstance
instead. ExtensionBindingsContext has an example of this.

[Mihai Parparita -not on Chrome, 2011/09/07 00:05:03]

Done.

+
+// Extra data to be passed to MakeWeak/CallbackMapWeakReferenceCallback to know
+// which entry to remove from which map.
+struct CallbackMapData {
+  CallbackMap* callback_map;
+  int install_id;
+};
+
+// Disposes of a callback function and its corresponding entry in the callback
+// map.
+static void CallbackMapWeakReferenceCallback(
+    v8::Persistent<v8::Value> context, void* data) {
+  CallbackMapData* callback_map_data = static_cast<CallbackMapData*>(data);
+  callback_map_data->callback_map->erase(callback_map_data->install_id);
+
+  delete callback_map_data;
+  context.Dispose();
+}
+
+// Adds |callback_param| (assumed to be a function) to |callback_map| under the
+// |install_id| key. Will be removed from the map when the value is about to be
+// GCed.
+static void AddToCallbackMap(int install_id,
+                             v8::Local<v8::Value> callback_param,
+                             CallbackMap* callback_map) {
+  CHECK(callback_param->IsFunction());
+  CallbackMapData* callback_map_data = new CallbackMapData();
+  callback_map_data->install_id = install_id;
+  callback_map_data->callback_map = callback_map;
+
+  v8::Local<v8::Function> function = v8::Function::Cast(*callback_param);
+  v8::Persistent<v8::Function> wrapper =
+      v8::Persistent<v8::Function>::New(function);
+  (*callback_map)[install_id] = wrapper;
+  wrapper.MakeWeak(callback_map_data, CallbackMapWeakReferenceCallback);
+}
+
+} // anonymous namespace
+
+class ExtensionImpl : public v8::Extension {
  public:
-  ChromeWebstoreExtensionWrapper() :
+  ExtensionImpl() :
     v8::Extension(
-        kWebstoreExtensionName,
-        "var chrome;"
-        "if (!chrome)"
-        "  chrome = {};"
+        kWebstoreV8ExtensionName,
+        "var chrome = chrome || {};"
         "if (!chrome.webstore) {"
         "  chrome.webstore = new function() {"
-        "    native function Install();"
+        "    native function Install(preferredStoreUrl, onSuccess, onFailure);"
         "    this.install = Install;"
         "  };"
         "}") {
   }
 
   virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
       v8::Handle<v8::String> name) {
     if (name->Equals(v8::String::New("Install"))) {
       return v8::FunctionTemplate::New(Install);
     } else {
       return v8::Handle<v8::FunctionTemplate>();
     }
   }
 
   static v8::Handle<v8::Value> Install(const v8::Arguments& args) {
     WebFrame* frame = WebFrame::frameForCurrentContext();
     if (!frame || !frame->view())
       return v8::Undefined();
 
     RenderView* render_view = RenderView::FromWebView(frame->view());
     if (!render_view)
       return v8::Undefined();
 
+    std::string preferred_store_link_url;
+    if (args.Length() >= 1 && !args[0]->IsUndefined()) {
+      if (args[0]->IsString()) {
+        preferred_store_link_url = std::string(*v8::String::Utf8Value(args[0]));
+      } else {
+        v8::ThrowException(v8::String::New(kPreferredStoreLinkUrlNotAString));
+        return v8::Undefined();
+      }
+    }
+
     std::string webstore_item_id;
     std::string error;
-    if (GetWebstoreItemIdFromFrame(frame, &webstore_item_id, &error)) {
-      ExtensionRenderViewHelper* helper =
-          ExtensionRenderViewHelper::Get(render_view);
-      helper->InlineWebstoreInstall(webstore_item_id);
-    } else {
+    if (!GetWebstoreItemIdFromFrame(
+        frame, preferred_store_link_url, &webstore_item_id, &error)) {
       v8::ThrowException(v8::String::New(error.c_str()));
+      return v8::Undefined();
     }
 
+    int install_id = next_install_id++;
+    if (args.Length() >= 2 && !args[1]->IsUndefined()) {
+      if (args[1]->IsFunction()) {
+        AddToCallbackMap(install_id, args[1], &success_callbacks);
+      } else {
+        v8::ThrowException(v8::String::New(kSuccessCallbackNotAFunctionError));
+        return v8::Undefined();
+      }
+    }
+    if (args.Length() >= 3 && !args[2]->IsUndefined()) {
+      if (args[2]->IsFunction()) {
+        AddToCallbackMap(install_id, args[2], &failure_callbacks);
+      } else {
+        v8::ThrowException(v8::String::New(kFailureCallbackNotAFunctionError));
+        return v8::Undefined();
+      }
+    }
+
+    ExtensionRenderViewHelper* helper =
+        ExtensionRenderViewHelper::Get(render_view);
+    helper->InlineWebstoreInstall(
+        install_id, webstore_item_id, frame->document().url());
     return v8::Undefined();
   }
 
  private:
   // Extracts a Web Store item ID from a <link rel="chrome-webstore-item"
   // href="https://chrome.google.com/webstore/detail/id"> node found in the
   // frame. On success, true will be returned and the |webstore_item_id|
   // parameter will be populated with the ID. On failure, false will be returned
   // and |error| will be populated with the error.
   static bool GetWebstoreItemIdFromFrame(
-      WebFrame* frame, std::string* webstore_item_id, std::string* error) {
+      WebFrame* frame, const std::string& preferred_store_link_url,
+      std::string* webstore_item_id, std::string* error) {
     if (frame != frame->top()) {
       *error = kNotInTopFrameError;
       return false;
     }
 
     if (!frame->isProcessingUserGesture()) {
       *error = kNotUserGestureError;
       return false;
     }
 
@@ skipping 20 matching lines @@
 
       if (!elem.hasTagName("link") || !elem.hasAttribute("rel") ||
           !elem.hasAttribute("href"))
         continue;
 
       std::string rel = elem.getAttribute("rel").utf8();
       if (!LowerCaseEqualsASCII(rel, kWebstoreLinkRelation))
         continue;
 
       std::string webstore_url_string(elem.getAttribute("href").utf8());
+
+      if (!preferred_store_link_url.empty() &&
+          preferred_store_link_url != webstore_url_string) {
+        continue;
+      }
+
       GURL webstore_url = GURL(webstore_url_string);
       if (!webstore_url.is_valid()) {
         *error = kInvalidWebstoreItemUrlError;
         return false;
       }
 
       if (webstore_url.scheme() != webstore_base_url.scheme() ||
           webstore_url.host() != webstore_base_url.host() ||
           !StartsWithASCII(
               webstore_url.path(), webstore_base_url.path(), true)) {
@@ skipping 18 matching lines @@
 
       *webstore_item_id = candidate_webstore_item_id;
       return true;
     }
 
     *error = kNoWebstoreItemLinkFoundError;
     return false;
   }
 };
 
+// static
 v8::Extension* ChromeWebstoreExtension::Get() {
-  return new ChromeWebstoreExtensionWrapper();
+  return new ExtensionImpl();
 }
 
-}  // namespace extensions_v8
+// static
+void ChromeWebstoreExtension::HandleInstallResponse(int install_id,
+                                                    bool success,
+                                                    const std::string& error) {
+  const CallbackMap& callback_map =
+      success ? success_callbacks : failure_callbacks;
+  CallbackMap::const_iterator iter = callback_map.find(install_id);
+
+  if (iter == callback_map.end() || iter->second.IsEmpty()) return;
+  const v8::Persistent<v8::Function>& function = (*iter).second;
+
+  v8::HandleScope handle_scope;
+  v8::Context::Scope context_scope(function->CreationContext());
+  v8::Handle<v8::Value> argv[1];
+  argv[0] = v8::String::New(error.c_str());
+  function->Call(v8::Object::New(), arraysize(argv), argv);

[Aaron Boodman, 2011/09/06 23:24:32]

You can remove the function from the map after this call.

[Mihai Parparita -not on Chrome, 2011/09/07 00:05:03]

Done.

+}