Make JsEngine::Evaluate() return a wrapper for v8::Value to accessdifferent variable types easily

src/JsValue.cpp

Index: src/JsValue.cpp
===================================================================
new file mode 100644
--- /dev/null
+++ b/src/JsValue.cpp
@@ -0,0 +1,185 @@
+#include <AdblockPlus.h>
+
+namespace
+{
+  std::string fromV8String(v8::Handle<v8::Value> value)
+  {
+    v8::String::Utf8Value stringValue(value);
+    if (stringValue.length())
+      return std::string(*stringValue, stringValue.length());
+    else
+      return std::string();
+  }
+
+  v8::Local<v8::String> toV8String(const std::string& str)
+  {
+    return v8::String::New(str.c_str(), str.length());
+  }
+}
+
+AdblockPlus::JsValue::JsValue(AdblockPlus::JsEngine& jsEngine,
+      v8::Handle<v8::Value> value)
+    : jsEngine(jsEngine),
+      value(v8::Persistent<v8::Value>::New(jsEngine.isolate, value))
+{
+}
+
+AdblockPlus::JsValue::~JsValue()
+{
+  value.Dispose(jsEngine.isolate);
+}
+
+bool AdblockPlus::JsValue::IsUndefined() const
+{
+  return value->IsUndefined();
+}
+
+bool AdblockPlus::JsValue::IsNull() const
+{
+  return value->IsNull();
+}
+
+bool AdblockPlus::JsValue::IsString() const
+{
+  return value->IsString() || value->IsStringObject();
+}
+
+bool AdblockPlus::JsValue::IsNumber() const
+{
+  return value->IsNumber() || value->IsNumberObject();
+}
+
+bool AdblockPlus::JsValue::IsBool() const
+{
+  return value->IsBoolean() || value->IsBooleanObject();
+}
+
+bool AdblockPlus::JsValue::IsObject() const
+{
+  return value->IsObject();
+}
+
+bool AdblockPlus::JsValue::IsArray() const
+{
+  return value->IsArray();
+}
+
+bool AdblockPlus::JsValue::IsFunction() const
+{
+  return value->IsFunction();
+}
+
+std::string AdblockPlus::JsValue::AsString() const
+{
+  const JsEngine::Context context(jsEngine);
+  return fromV8String(value);
+}
+
+int64_t AdblockPlus::JsValue::AsInt() const
+{
+  const JsEngine::Context context(jsEngine);
+  return value->IntegerValue();
+}
+
+bool AdblockPlus::JsValue::AsBool() const
+{
+  const JsEngine::Context context(jsEngine);
+  return value->BooleanValue();
+}
+
+AdblockPlus::JsValueList AdblockPlus::JsValue::AsList() const
+{
+  if (!IsArray())
+    throw std::runtime_error("Cannot convert a non-array to list");
+
+  const JsEngine::Context context(jsEngine);
+  JsValueList result;
+  v8::Persistent<v8::Array> array = v8::Persistent<v8::Array>::Cast(value);
+  uint32_t length = array->Length();
+  for (uint32_t i = 0; i < length; i++)
+  {
+    v8::Local<v8::Value> item = array->Get(i);
+    result.push_back(JsValuePtr(new JsValue(jsEngine, item)));
+  }
+  return result;
+}
+
+AdblockPlus::JsValuePtr AdblockPlus::JsValue::GetProperty(const std::string& name) const
+{
+  if (!IsObject())
+    throw new std::runtime_error("Attempting to get property of a non-object");
+
+  const JsEngine::Context context(jsEngine);
+  v8::Local<v8::String> property = toV8String(name);
+  v8::Persistent<v8::Object> obj = v8::Persistent<v8::Object>::Cast(value);
+  return JsValuePtr(new JsValue(jsEngine, obj->Get(property)));
+}
+
+void AdblockPlus::JsValue::SetProperty(const std::string& name, v8::Handle<v8::Value> val)
+{
+  if (!IsObject())
+    throw new std::runtime_error("Attempting to set property on a non-object");
+
+  v8::Local<v8::String> property = toV8String(name);
+  v8::Persistent<v8::Object> obj = v8::Persistent<v8::Object>::Cast(value);
+  obj->Set(property, val);
+}
+
+void AdblockPlus::JsValue::SetProperty(const std::string& name, const std::string& val)
+{
+  const JsEngine::Context context(jsEngine);
+  SetProperty(name, toV8String(val));
+}
+
+void AdblockPlus::JsValue::SetProperty(const std::string& name, int64_t val)
+{
+  const JsEngine::Context context(jsEngine);
+  SetProperty(name, v8::Integer::New(val));
+}
+
+void AdblockPlus::JsValue::SetProperty(const std::string& name, bool val)
+{
+  const JsEngine::Context context(jsEngine);
+  SetProperty(name, v8::Boolean::New(val));
+}
+
+std::string AdblockPlus::JsValue::GetClassName() const
+{
+  if (!IsObject())
+    throw new std::runtime_error("Cannot get constructor of a non-object");
+
+  const JsEngine::Context context(jsEngine);
+  v8::Persistent<v8::Object> obj = v8::Persistent<v8::Object>::Cast(value);
+  return fromV8String(obj->GetConstructorName());
+}
+
+AdblockPlus::JsValuePtr AdblockPlus::JsValue::Call(
+    const JsValueList& params,
+    AdblockPlus::JsValuePtr thisPtr) const
+{
+  if (!IsFunction())
+    throw new std::runtime_error("Attempting to call a non-function");
+
+  const JsEngine::Context context(jsEngine);
+
+  if (!thisPtr)
+    thisPtr = JsValuePtr(new JsValue(jsEngine, jsEngine.context->Global()));
+  if (!thisPtr->IsObject())
+    throw new std::runtime_error("`this` pointer has to be an object");
+  v8::Persistent<v8::Object> thisObj = v8::Persistent<v8::Object>::Cast(thisPtr->value);
+
+  size_t argc = params.size();
+  v8::Handle<v8::Value>* argv = new v8::Handle<v8::Value>[argc];
+  for (size_t i = 0; i < argc; ++i)
+    argv[i] = params[i]->value;
+
+  const v8::TryCatch tryCatch;
+  v8::Persistent<v8::Function> func = v8::Persistent<v8::Function>::Cast(value);
+  v8::Local<v8::Value> result = func->Call(thisObj, argc, argv);
+  delete argv;
+
+  if (tryCatch.HasCaught())
+    throw AdblockPlus::JsError(tryCatch.Exception(), tryCatch.Message());
+
+  return JsValuePtr(new JsValue(jsEngine, result));
+}