Issue 2325 - Add a way to set settings in libadblockplus for FRP and automatic updates

src/FilterEngine.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 116 matching lines @@
   params.push_back(shared_from_this());
   JsValuePtr result = func->Call(params);
   return result->AsBool();
 }
 
 bool Subscription::operator==(const Subscription& subscription) const
 {
   return GetProperty("url")->AsString() == subscription.GetProperty("url")->AsString();
 }
 
-FilterEngine::FilterEngine(JsEnginePtr jsEngine)
+FilterEngine::FilterEngine(JsEnginePtr jsEngine, std::map<std::string, std::string> preconfiguredPrefs)
     : jsEngine(jsEngine), initialized(false), firstRun(false), updateCheckId(0)
 {
   jsEngine->SetEventCallback("init", std::tr1::bind(&FilterEngine::InitDone,
       this, std::tr1::placeholders::_1));
 
   {
     // Lock the JS engine while we are loading scripts, no timeouts should fire
     // until we are done.
     const JsContext context(jsEngine);
+
+    // Set the precongiured prefs
+    jsEngine->Evaluate(std::string("var Preconfig = {};"));

[Felix Dahlke, 2015/06/09 19:40:51]

1. _preconfiguredPrefs would be a better name. We usually prefix internal
globals provided by libadblockplus with _, and being an object and not a module
or type, it should start with a lower case letter.

2. I think using JsEngine->Evaluate() to populate this is too hacky. We're
currently setting all globals in JsEngine, which is why AppInfo is passed into
it - that however is bad as well. So what I believe we should do at this stage
is: Add an accessor for the global JsValue to JsEngine. With that, we can create
the object using JsEngine->NewObject() and use the JsValue API to populate it,
then add it as a property to the global JsValue. (We should actually use the
same approach for AppInfo too, then, but that's something for a follow-up
issue/patch.)

[Oleksandr, 2015/06/10 08:40:30]

I agree it was hacky, but it had it's advantages. There was no need to carry 
the type of the preconfig this way. Which is both good and bad, I suppose. Now
the preconfig is JsValuePtr not just a string.

+    for (auto it = preconfiguredPrefs.begin(); it != preconfiguredPrefs.end(); it++)

[Felix Dahlke, 2015/06/09 19:40:51]

It's still C++03 here.

+    {
+      jsEngine->Evaluate(std::string("Preconfig.") + it->first + std::string(" = ") + it->second);
+    }
+
     for (int i = 0; !jsSources[i].empty(); i += 2)
       jsEngine->Evaluate(jsSources[i + 1], jsSources[i]);
   }
 
   // TODO: This should really be implemented via a conditional variable
   while (!initialized)
     ::Sleep(10);
 }
 
 namespace
@@ skipping 258 matching lines @@
 }
 
 int FilterEngine::CompareVersions(const std::string& v1, const std::string& v2)
 {
   JsValueList params;
   params.push_back(jsEngine->NewValue(v1));
   params.push_back(jsEngine->NewValue(v2));
   JsValuePtr func = jsEngine->Evaluate("API.compareVersions");
   return func->Call(params)->AsInt();
 }