Issue 4931 - add possibility to not send data depending on connection properties

src/FilterEngine.cpp

Index: src/FilterEngine.cpp
diff --git a/src/FilterEngine.cpp b/src/FilterEngine.cpp
index fd4ff4d3634dbd141d13d847b36aea9910bcb5a9..87a4d4dfd60ff43a142411116bff42e47a4af868 100644
--- a/src/FilterEngine.cpp
+++ b/src/FilterEngine.cpp
@@ -178,9 +178,27 @@ void FilterEngine::CreateAsync(const JsEnginePtr& jsEngine,
 {
   FilterEnginePtr filterEngine(new FilterEngine(jsEngine));
   auto sync = std::make_shared<Sync>();
-  jsEngine->SetEventCallback("_init", [jsEngine, filterEngine, onCreated, sync](JsValueList& params)
+  auto isConnectionAllowed = params.isConnectionAllowed;

[Oleksandr, 2017/03/16 14:19:53]

The naming here is highly confusing, IMO. How about isConnectionAllowedCallback?

[sergei, 2017/03/16 16:25:22]

No objections, fixed.

+  if (isConnectionAllowed)
+    jsEngine->SetIsConnectionAllowedCallback([sync, jsEngine]()->bool
+    {
+      sync->Wait();
+      return jsEngine->IsConnectionAllowed();
+    });
+  jsEngine->SetEventCallback("_init", [jsEngine, filterEngine, onCreated, sync, isConnectionAllowed](JsValueList& params)
   {
     filterEngine->firstRun = params.size() && params[0]->AsBool();
+    if (isConnectionAllowed)
+    {
+      std::weak_ptr<FilterEngine> weakFilterEngine = filterEngine;
+      jsEngine->SetIsConnectionAllowedCallback([weakFilterEngine, isConnectionAllowed]()->bool
+      {
+        auto filterEngine = weakFilterEngine.lock();
+        if (!filterEngine)
+          return false;
+        return isConnectionAllowed(filterEngine->GetAllowedConnectionType().get());
+      });
+    }
     sync->Set();
     onCreated(filterEngine);
     jsEngine->RemoveEventCallback("_init");
@@ -427,7 +445,8 @@ void FilterEngine::SetPref(const std::string& pref, JsValuePtr value)
   JsValuePtr func = jsEngine->Evaluate("API.setPref");
   JsValueList params;
   params.push_back(jsEngine->NewValue(pref));
-  params.push_back(value);
+  if (value)

[Oleksandr, 2017/03/16 14:19:53]

Nit: this doesn't look related, is it?

[sergei, 2017/03/16 16:25:22]

It's related, now we can call SetPref(nullptr) and if value is nullptr then it
crashes afterwards. nullptr here means there is no value, what is undefined in
terms of JavaScript, so we either should pass undefined or not pass the
argument. I have chosen the latter.

+    params.push_back(value);
   func->Call(params);
 }
 
@@ -494,6 +513,19 @@ void FilterEngine::RemoveFilterChangeCallback()
   jsEngine->RemoveEventCallback("filterChange");
 }
 
+void FilterEngine::SetAllowedConnectionType(const std::string* value)
+{
+  SetPref("allowed_connection_type", value ? jsEngine->NewValue(*value) : nullptr);
+}
+
+std::unique_ptr<std::string> FilterEngine::GetAllowedConnectionType()
+{
+   auto prefValue = GetPref("allowed_connection_type");
+   if (prefValue->IsUndefined())
+     return nullptr;
+   return std::unique_ptr<std::string>(new std::string(prefValue->AsString()));
+}
+
 void FilterEngine::FilterChanged(FilterEngine::FilterChangeCallback callback, JsValueList& params)
 {
   std::string action(params.size() >= 1 && !params[0]->IsNull() ? params[0]->AsString() : "");