Issues #1163, #1173 - refactor CPluginUserSettings

src/plugin/PluginUserSettings.cpp

 #include "PluginStdAfx.h"
 #include "PluginUserSettings.h"
 #include <algorithm>
 #include "PluginSettings.h"
 #include "PluginClient.h"
 #include "../shared/Dictionary.h"
-
-static const CString s_GetMessage = L"GetMessage";
-static const CString s_GetLanguageCount = L"GetLanguageCount";
-static const CString s_GetLanguageByIndex = L"GetLanguageByIndex";
-static const CString s_GetLanguageTitleByIndex = L"GetLanguageTitleByIndex";
-static const CString s_SetLanguage = L"SetLanguage";
-static const CString s_GetLanguage = L"GetLanguage";
-static const CString s_GetWhitelistDomains = L"GetWhitelistDomains";
-static const CString s_AddWhitelistDomain = L"AddWhitelistDomain";
-static const CString s_RemoveWhitelistDomain = L"RemoveWhitelistDomain";
-static const CString s_GetAppLocale = L"GetAppLocale";
-static const CString s_GetDocumentationLink = L"GetDocumentationLink";
-static const CString s_IsAcceptableAdsEnabled = L"IsAcceptableAdsEnabled";
-static const CString s_SetAcceptableAdsEnabled = L"SetAcceptableAdsEnabled";
-static const CString s_Methods[] = {s_GetMessage, s_GetLanguageCount, s_GetLanguageByIndex, s_GetLanguageTitleByIndex, s_SetLanguage, s_GetLanguage, s_GetWhitelistDomains, s_AddWhitelistDomain, s_RemoveWhitelistDomain, s_GetAppLocale, s_GetDocumentationLink, s_IsAcceptableAdsEnabled, s_SetAcceptableAdsEnabled};
-
-CPluginUserSettings::CPluginUserSettings()
-{
-}
-
+#include <unordered_map>
+
+namespace
+{
+  enum UserSettingsMethods
+  {
+    dispatchID_GetMessage = 0,
+    dispatchID_GetLanguageCount,
+    dispatchID_GetLanguageByIndex,
+    dispatchID_GetLanguageTitleByIndex,
+    dispatchID_SetLanguage,
+    dispatchID_GetLanguage,
+    dispatchID_GetWhitelistDomains,
+    dispatchID_AddWhitelistDomain,
+    dispatchID_RemoveWhitelistDomain,
+    dispatchID_GetAppLocale,
+    dispatchID_GetDocumentationLink,
+    dispatchID_IsAcceptableAdsEnabled,
+    dispatchID_SetAcceptableAdsEnabled
+  };
+
+  std::unordered_map<std::wstring, DISPID> InitMethodIndex()
+  {
+    std::unordered_map<std::wstring, DISPID> m;
+    // try-block for safety during static initialization
+    try
+    {
+      m.emplace(L"GetMessage", dispatchID_GetMessage);

[Oleksandr, 2014/08/17 22:52:01]

It's outside the scope of this review, but since we are already re-factoring
this, I wouldn't mind to get rid of that really long Invoke method below. I am
thinking of something like this

typedef (HRESULT JavaScriptMethodInvoke)(DISPPARAMS* pDispparams, VARIANT*
pVarResult, EXCEPINFO* pExcepinfo, UINT* pArgErr)

std::unordered_map<DISPID, JavaScriptMethodInvoke> m_methods;

Then for each DISPID we could have a separate method, and all Invoke would do
would just call something like:
return m_methods[dispidMember]->second(pDispparams, pVarResult, pExcepinfo,
pArgErr)

Shall we put this into our issues list?

[Eric, 2014/09/29 18:45:41]

Discussion points.
1. I wouldn't mind breaking up the Invoke code so that the central functionality
of each method is implemented in its own function.
2. I would prefer to centralize all the type conversion and validation functions
here so that the individual functions have interfaces with natural C++ types and
not the Microsoft API conventions.
2a. For example, only some of the functions need to return a result. Defining
'pVarResult' as an argument for such functions loses the opportunity for the
function signature to signify what it does.
It would be a low priority issue in every case I can think of. I don't see a
need to plan to rewrite it yet.

[Oleksandr, 2014/10/02 20:36:53]

Creating a low priority issue in our issue tracker would enable developers from
outside the team to just go and do it, if the feel like it. 

On 2014/09/29 18:45:41, Eric wrote:

[Eric, 2014/10/14 22:23:50]

I wrote an issue for the slightly larger task of cleaning up the Invoke
implementations generally. See https://issues.adblockplus.org/ticket/1163 The
subtask of breaking out each dispatch ID to its own function is in there. Let me
know if this is sufficient.

+      m.emplace(L"GetLanguageCount", dispatchID_GetLanguageCount);
+      m.emplace(L"GetLanguageByIndex", dispatchID_GetLanguageByIndex);
+      m.emplace(L"GetLanguageTitleByIndex", dispatchID_GetLanguageTitleByIndex);
+      m.emplace(L"SetLanguage", dispatchID_SetLanguage);
+      m.emplace(L"GetLanguage", dispatchID_GetLanguage);
+      m.emplace(L"GetWhitelistDomains", dispatchID_GetWhitelistDomains);
+      m.emplace(L"AddWhitelistDomain", dispatchID_AddWhitelistDomain);
+      m.emplace(L"RemoveWhitelistDomain", dispatchID_RemoveWhitelistDomain);
+      m.emplace(L"GetAppLocale", dispatchID_GetAppLocale);
+      m.emplace(L"GetDocumentationLink", dispatchID_GetDocumentationLink);
+      m.emplace(L"IsAcceptableAdsEnabled", dispatchID_IsAcceptableAdsEnabled);
+      m.emplace(L"SetAcceptableAdsEnabled", dispatchID_SetAcceptableAdsEnabled);
+    }
+    catch(...)
+    {
+    }
+    return m;
+  }
+
+  std::unordered_map<std::wstring, DISPID> methodIndex = InitMethodIndex();
+}
 
 STDMETHODIMP CPluginUserSettings::QueryInterface(REFIID riid, void **ppvObj)
 {
-  if (IID_IUnknown == riid  ||  IID_IDispatch == riid)
-  {
-    *ppvObj = (LPVOID)this;
-    return NOERROR;
-  }
-
+  // Entry point, but no exception handler; nothing here can throw

[Oleksandr, 2014/08/17 22:52:01]

This comment and all the others concerning the exception safety are useful in
this review, but would be weird to have in the actual code, IMHO.

[Eric, 2014/09/29 18:45:41]

I would like to have some kind of documentation in the code that identifies each
of the entry points in some way that can be searched with a regular expression.
This is to allow code audit for issue #1173.

It's a separate issue (for me) whether those comments persist in the code after
#1173 is done. Personally, I'd leave them there because they have non-ordinary
interactions with the external world. I'd prefer an in-language specification
but that's not available, so I'll settle for a comment. (Note: C++11 generalized
attributes could work, but they are not supported even in VS 2013.)

I'm open with how to write such comments.

Also, I'm also open to putting in a try-catch statement even though nothing can
throw. That would remove the need for the second half of the comment.

[Oleksandr, 2014/10/02 20:36:53]

In that case, it would seem less intrusive to have these comments right before
the method declaration, IMHO.
 
On 2014/09/29 18:45:41, Eric wrote:

+  if (!ppvObj)
+  {
+    return E_POINTER;
+  }
+  if (riid == IID_IUnknown || riid == IID_IDispatch) // GUID comparison does not throw
+  {
+    *ppvObj = static_cast<void *>(this);
+    return S_OK;
+  }
   return E_NOINTERFACE;
 }
 
-
-/*
-Since CPluginUserSettings is not allocated on the heap, 'AddRef' and 'Release' don't need reference counting,
-because CPluginUserSettings won't be deleted when reference counter == 0
-*/
-
+/**
+ * \par Limitation
+ *   CPluginUserSettings is not allocated on the heap.
+ *   It appears only as a member variable in CPluginTabBase.
+ *   'AddRef' and 'Release' don't need reference counting because they don't present COM factories.
+ */
 ULONG __stdcall CPluginUserSettings::AddRef()
 {
   return 1;
 }
 
-
 ULONG __stdcall CPluginUserSettings::Release()
 {
   return 1;
 }
 
-
 STDMETHODIMP CPluginUserSettings::GetTypeInfoCount(UINT* pctinfo)
 {
   return E_NOTIMPL;
 }
 
-
 STDMETHODIMP CPluginUserSettings::GetTypeInfo(UINT itinfo, LCID lcid, ITypeInfo** pptinfo)
 {
   return E_NOTIMPL;
 }
 
-
-STDMETHODIMP CPluginUserSettings::GetIDsOfNames(REFIID riid, LPOLESTR* rgszNames, UINT cNames, LCID lcid, DISPID* rgdispid)
-{
-  if (!rgszNames)
-    return E_POINTER;
-
-  if (!rgdispid)
-    return E_POINTER;
-
-  if (1 != cNames)
+/**
+ * \par Limitation
+ *   The specification for this method in IDispatch maps an array of names to an array of identifiers.
+ *   This version only supports single-element arrays, which is enough for IE's JavaScript interpreter.
+ */
+STDMETHODIMP CPluginUserSettings::GetIDsOfNames(REFIID, LPOLESTR* name, UINT count, LCID, DISPID* id)
+{
+  // Entry point exception handler
+  try
+  {
+    if (!name || !id)
+    {
+      return E_POINTER;
+    }
+    if (count != 1)
+    {
+      return E_FAIL;
+    }
+    auto item = methodIndex.find(*name); // unordered_map::find is not declared noexcept
+    if (item==methodIndex.end())
+    {
+      return DISP_E_UNKNOWNNAME;
+    }
+    *id = item->second;
+  }
+  catch(...)
+  {
     return E_FAIL;
-
-  size_t indxMethod = 0;
-  for (; indxMethod < countof(s_Methods); indxMethod++)
-  {
-    if (*rgszNames == s_Methods[indxMethod])
-      break;
-  }
-
-  if (indxMethod == countof(s_Methods))
-    return DISP_E_MEMBERNOTFOUND;
-
-  *rgdispid = static_cast<DISPID>(indxMethod);
-
+  }
   return S_OK;
 }
 
-
-static CString sGetLanguage()
-{
-  CPluginSettings* settings = CPluginSettings::GetInstance();
-  return settings->GetSubscription();
-}
-
-
 CStringW sGetMessage(const CString& section, const CString& key)
 {
   Dictionary* dictionary = Dictionary::GetInstance();
   return CStringW(dictionary->Lookup(std::string(CW2A(section)), std::string(CW2A(key))).c_str());
 }
 
-std::wstring sGetMessage(const std::string& section, const std::string& key)
-{
-  Dictionary* dictionary = Dictionary::GetInstance();
-  return dictionary->Lookup(section, key);
-}
-
-
 STDMETHODIMP CPluginUserSettings::Invoke(DISPID dispidMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS* pDispparams, VARIANT* pVarResult,
                                          EXCEPINFO* pExcepinfo, UINT* pArgErr)
 {
-  if (!pDispparams)
-    return E_POINTER;
-
-  if (!pExcepinfo)
-    return E_POINTER;
-
-  if (pDispparams->cNamedArgs)
-    return DISP_E_NONAMEDARGS;
-
-  CPluginSettings* settings = CPluginSettings::GetInstance();
-
-  if (dispidMember  < 0  ||  dispidMember >= countof(s_Methods))
-    return DISP_E_BADINDEX;
-
-  const CString& method = s_Methods[dispidMember];
-
-  if (s_GetMessage == method)
-  {
-    if (2 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_BSTR != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    if (pVarResult)
-    {
-      CComBSTR key = pDispparams->rgvarg[0].bstrVal;
-      CComBSTR section = pDispparams->rgvarg[1].bstrVal;
-      CStringW message = sGetMessage((BSTR)section, (BSTR)key);
-
-      pVarResult->vt = VT_BSTR;
-      pVarResult->bstrVal = SysAllocString(message);
-    }
-  }
-  else if (s_GetLanguageCount == method)
-  {
-    if (pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (pVarResult)
-    {
-      std::map<CString, CString> languageList = settings->GetFilterLanguageTitleList();
-
-      pVarResult->vt = VT_I4;
-      pVarResult->lVal = static_cast<LONG>(languageList.size());
-    }
-  }
-  else if (s_GetLanguageByIndex == method)
-  {
-    if (1 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_I4 != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    if (pVarResult)
-    {
-      int indx = pDispparams->rgvarg[0].lVal;
-
-      std::map<CString, CString> languageTitleList = settings->GetFilterLanguageTitleList();
-
-      if (indx < 0  ||  indx >= (int)languageTitleList.size())
-        return DISP_E_EXCEPTION;
-
-      CString language;
-
-      int curIndx = 0;
-      for(std::map<CString, CString>::const_iterator it = languageTitleList.begin(); it != languageTitleList.end(); ++it)
-      {
-        if (curIndx == indx)
-        {
-          language = it->first;
-          break;
-        }
-
-        curIndx++;
-      }
-
-      pVarResult->vt = VT_BSTR;
-      pVarResult->bstrVal = SysAllocString(language);
-    }
-  }
-  else if (s_GetLanguageTitleByIndex == method)
-  {
-    if (1 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_I4 != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    if (pVarResult)
-    {
-      int indx = pDispparams->rgvarg[0].lVal;
-
-      std::map<CString, CString> languageTitleList = settings->GetFilterLanguageTitleList();
-
-      if (indx < 0  ||  indx >= (int)languageTitleList.size())
-        return DISP_E_EXCEPTION;
-
-      CString languageTitle;
-
-      int curIndx = 0;
-      for(std::map<CString, CString>::const_iterator it = languageTitleList.begin(); it != languageTitleList.end(); ++it)
-      {
-        if (curIndx == indx)
-        {
-          languageTitle = it->second;
-          break;
-        }
-
-        curIndx++;
-      }
-
-      pVarResult->vt = VT_BSTR;
-      pVarResult->bstrVal = SysAllocString(languageTitle);
-    }
-  }
-  else if (s_SetLanguage == method)
-  {
-    if (1 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_BSTR != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    CComBSTR url = pDispparams->rgvarg[0].bstrVal;
-
-    settings->SetSubscription((BSTR)url);
-  }
-  else if (s_GetLanguage == method)
-  {
-    if (pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (pVarResult)
-    {
-      CString url = settings->GetSubscription();
-
-      pVarResult->vt = VT_BSTR;
-      pVarResult->bstrVal = SysAllocString(url);
-    }
-  }
-  else if (s_GetWhitelistDomains == method)
-  {
-    if (pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (pVarResult)
-    {
-      std::vector<std::wstring> whiteList = settings->GetWhiteListedDomainList();
-      CString sWhiteList;
-      for (size_t i = 0; i < whiteList.size(); i++)
-      {
-        if (!sWhiteList.IsEmpty())
-        {
-          sWhiteList += ',';
-        }
-        sWhiteList += CString(whiteList[i].c_str());
-      }
-
-      pVarResult->vt = VT_BSTR;
-      pVarResult->bstrVal = SysAllocString(sWhiteList);
-    }
-  }
-  else if (s_AddWhitelistDomain == method)
-  {
-    if (1 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_BSTR != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    CComBSTR domain = pDispparams->rgvarg[0].bstrVal;
-    if (domain.Length())
-    {
-      settings->AddWhiteListedDomain((BSTR)domain);
-    }
-  }
-  else if (s_RemoveWhitelistDomain == method)
-  {
-    if (1 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_BSTR != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    CComBSTR domain = pDispparams->rgvarg[0].bstrVal;
-    if (domain.Length())
-    {
-      settings->RemoveWhiteListedDomain((BSTR)domain);
-    }
-  }
-  else if (s_GetAppLocale == method)
-  {
-    if (0 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    pVarResult->vt = VT_BSTR;
-    pVarResult->bstrVal = SysAllocString(settings->GetAppLocale());
-  }
-  else if (s_GetDocumentationLink == method)
-  {
-    if (0 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    pVarResult->vt = VT_BSTR;
-    pVarResult->bstrVal = SysAllocString(settings->GetDocumentationLink());
-  }
-  else if (s_IsAcceptableAdsEnabled == method)
-  {
-    if (0 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    pVarResult->vt = VT_BOOL;
-    pVarResult->boolVal = CPluginClient::GetInstance()->IsAcceptableAdsEnabled();
-  }
-  else if (s_SetAcceptableAdsEnabled == method)
-  {
-    if (1 != pDispparams->cArgs)
-      return DISP_E_BADPARAMCOUNT;
-
-    if (VT_BOOL != pDispparams->rgvarg[0].vt)
-      return DISP_E_TYPEMISMATCH;
-
-    bool enable = pDispparams->rgvarg[0].boolVal;
-
-    if (enable)
-    {
-      CPluginClient* client = CPluginClient::GetInstance();
-      client->AddSubscription(client->GetPref(L"subscriptions_exceptionsurl", L""));
-    }
-    else
-    {
-      CPluginClient* client = CPluginClient::GetInstance();
-      client->RemoveSubscription(client->GetPref(L"subscriptions_exceptionsurl", L""));
-    }
-  }
-  else
-    return DISP_E_MEMBERNOTFOUND;
-
+  // Entry point exception handler
+  try
+  {
+    if (!pDispparams || !pExcepinfo)
+    {
+      return E_POINTER;
+    }
+    if (pDispparams->cNamedArgs != 0)
+    {
+      return DISP_E_NONAMEDARGS;
+    }
+
+    CPluginSettings* settings = CPluginSettings::GetInstance();
+
+    switch (dispidMember)
+    {
+    case dispatchID_GetMessage:
+      {
+        if (2 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_BSTR != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+        if (VT_BSTR != pDispparams->rgvarg[1].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        if (pVarResult)
+        {
+          CComBSTR key = pDispparams->rgvarg[0].bstrVal;
+          CComBSTR section = pDispparams->rgvarg[1].bstrVal;
+          CStringW message = sGetMessage((BSTR)section, (BSTR)key);
+
+          pVarResult->vt = VT_BSTR;
+          pVarResult->bstrVal = SysAllocString(message);
+        }
+      }
+      break;
+    case dispatchID_GetLanguageCount:
+      {
+        if (pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (pVarResult)
+        {
+          std::map<CString, CString> languageList = settings->GetFilterLanguageTitleList();
+
+          pVarResult->vt = VT_I4;
+          pVarResult->lVal = static_cast<LONG>(languageList.size());
+        }
+      }
+      break;
+    case dispatchID_GetLanguageByIndex:
+      {
+        if (1 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_I4 != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        if (pVarResult)
+        {
+          int indx = pDispparams->rgvarg[0].lVal;
+
+          std::map<CString, CString> languageTitleList = settings->GetFilterLanguageTitleList();
+
+          if (indx < 0  ||  indx >= (int)languageTitleList.size())
+            return DISP_E_EXCEPTION;
+
+          CString language;
+
+          int curIndx = 0;
+          for(std::map<CString, CString>::const_iterator it = languageTitleList.begin(); it != languageTitleList.end(); ++it)
+          {
+            if (curIndx == indx)
+            {
+              language = it->first;
+              break;
+            }
+
+            curIndx++;
+          }
+
+          pVarResult->vt = VT_BSTR;
+          pVarResult->bstrVal = SysAllocString(language);
+        }
+      }
+      break;
+    case dispatchID_GetLanguageTitleByIndex:
+      {
+        if (1 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_I4 != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        if (pVarResult)
+        {
+          int indx = pDispparams->rgvarg[0].lVal;
+
+          std::map<CString, CString> languageTitleList = settings->GetFilterLanguageTitleList();
+
+          if (indx < 0  ||  indx >= (int)languageTitleList.size())
+            return DISP_E_EXCEPTION;
+
+          CString languageTitle;
+
+          int curIndx = 0;
+          for(std::map<CString, CString>::const_iterator it = languageTitleList.begin(); it != languageTitleList.end(); ++it)
+          {
+            if (curIndx == indx)
+            {
+              languageTitle = it->second;
+              break;
+            }
+
+            curIndx++;
+          }
+
+          pVarResult->vt = VT_BSTR;
+          pVarResult->bstrVal = SysAllocString(languageTitle);
+        }
+      }
+      break;
+    case dispatchID_SetLanguage:
+      {
+        if (1 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_BSTR != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        CComBSTR url = pDispparams->rgvarg[0].bstrVal;
+
+        settings->SetSubscription((BSTR)url);
+      }
+      break;
+    case dispatchID_GetLanguage:
+      {
+        if (pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (pVarResult)
+        {
+          CString url = settings->GetSubscription();
+
+          pVarResult->vt = VT_BSTR;
+          pVarResult->bstrVal = SysAllocString(url);
+        }
+      }
+      break;
+    case dispatchID_GetWhitelistDomains:
+      {
+        if (pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (pVarResult)
+        {
+          std::vector<std::wstring> whiteList = settings->GetWhiteListedDomainList();
+          CString sWhiteList;
+          for (size_t i = 0; i < whiteList.size(); i++)
+          {
+            if (!sWhiteList.IsEmpty())
+            {
+              sWhiteList += ',';
+            }
+            sWhiteList += CString(whiteList[i].c_str());
+          }
+
+          pVarResult->vt = VT_BSTR;
+          pVarResult->bstrVal = SysAllocString(sWhiteList);
+        }
+      }
+      break;
+    case dispatchID_AddWhitelistDomain:
+      {
+        if (1 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_BSTR != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        CComBSTR domain = pDispparams->rgvarg[0].bstrVal;
+        if (domain.Length())
+        {
+          settings->AddWhiteListedDomain((BSTR)domain);
+        }
+      }
+      break;
+    case dispatchID_RemoveWhitelistDomain:
+      {
+        if (1 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_BSTR != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        CComBSTR domain = pDispparams->rgvarg[0].bstrVal;
+        if (domain.Length())
+        {
+          settings->RemoveWhiteListedDomain((BSTR)domain);
+        }
+      }
+      break;
+    case dispatchID_GetAppLocale:
+      {
+        if (0 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        pVarResult->vt = VT_BSTR;
+        pVarResult->bstrVal = SysAllocString(settings->GetAppLocale());
+      }
+      break;
+    case dispatchID_GetDocumentationLink:
+      {
+        if (0 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        pVarResult->vt = VT_BSTR;
+        pVarResult->bstrVal = SysAllocString(settings->GetDocumentationLink());
+      }
+      break;
+    case dispatchID_IsAcceptableAdsEnabled:
+      {
+        if (0 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        pVarResult->vt = VT_BOOL;
+        pVarResult->boolVal = CPluginClient::GetInstance()->IsAcceptableAdsEnabled();
+      }
+      break;
+    case dispatchID_SetAcceptableAdsEnabled:
+      {
+        if (1 != pDispparams->cArgs)
+          return DISP_E_BADPARAMCOUNT;
+
+        if (VT_BOOL != pDispparams->rgvarg[0].vt)
+          return DISP_E_TYPEMISMATCH;
+
+        bool enable = pDispparams->rgvarg[0].boolVal;
+
+        if (enable)
+        {
+          CPluginClient* client = CPluginClient::GetInstance();
+          client->AddSubscription(client->GetPref(L"subscriptions_exceptionsurl", L""));
+        }
+        else
+        {
+          CPluginClient* client = CPluginClient::GetInstance();
+          client->RemoveSubscription(client->GetPref(L"subscriptions_exceptionsurl", L""));
+        }
+      }
+      break;
+    default:
+      return DISP_E_MEMBERNOTFOUND;
+      break;
+    }
+  }
+  catch(...)
+  {
+    return E_FAIL;
+  }
   return S_OK;
 }