From 6beb7a69a1ec3630de41b9010b7282c7a2a75693 Mon Sep 17 00:00:00 2001
From: chriseth <c@ethdev.com>
Date: Tue, 11 Aug 2015 00:04:01 +0200
Subject: [PATCH] Provide global function loadScript to load external file.

---
 libjsengine/JSEngine.h     |  2 +-
 libjsengine/JSV8Engine.cpp | 46 +++++++++++++++++++++++++++++++++-----
 libjsengine/JSV8Engine.h   |  2 +-
 3 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/libjsengine/JSEngine.h b/libjsengine/JSEngine.h
index adebfdd13..961026b60 100644
--- a/libjsengine/JSEngine.h
+++ b/libjsengine/JSEngine.h
@@ -59,7 +59,7 @@ class JSEngine
 {
 public:
 	// should be used to evalute javascript expression
-	virtual T eval(char const* _cstr) const = 0;
+	virtual T eval(char const* _cstr, char const* _origin = "(shell)") const = 0;
 };
 
 }
diff --git a/libjsengine/JSV8Engine.cpp b/libjsengine/JSV8Engine.cpp
index 1a75a4620..471ea71e0 100644
--- a/libjsengine/JSV8Engine.cpp
+++ b/libjsengine/JSV8Engine.cpp
@@ -21,6 +21,8 @@
  */
 
 #include <memory>
+#include <iostream>
+#include <fstream>
 #include "JSV8Engine.h"
 #include "JSV8Printer.h"
 #include "libjsengine/JSEngineResources.hpp"
@@ -103,6 +105,35 @@ Handle<Value> ConsoleLog(Arguments const& _args)
 	return Undefined();
 }
 
+Handle<Value> LoadScript(Arguments const& _args)
+{
+	Local<External> wrap = Local<External>::Cast(_args.Data());
+	auto engine = reinterpret_cast<JSV8Engine const*>(wrap->Value());
+
+	if (_args.Length() < 1)
+		return v8::ThrowException(v8::String::New("Missing file name."));
+	if (_args[0].IsEmpty() || _args[0]->IsUndefined())
+		return v8::ThrowException(v8::String::New("Invalid file name."));
+	v8::String::Utf8Value fileName(_args[0]);
+	if (fileName.length() == 0)
+		return v8::ThrowException(v8::String::New("Invalid file name."));
+
+	std::ifstream is(*fileName, std::ifstream::binary);
+	if (!is)
+		return v8::ThrowException(v8::String::New("Error opening file."));
+
+	string contents;
+	is.seekg(0, is.end);
+	streamoff length = is.tellg();
+	if (length > 0)
+	{
+		is.seekg(0, is.beg);
+		contents.resize(length);
+		is.read(const_cast<char*>(contents.data()), length);
+	}
+
+	return engine->eval(contents.data(), *fileName).value();
+}
 
 class JSV8Scope
 {
@@ -158,11 +189,14 @@ JSV8Engine::JSV8Engine(): m_scope(new JSV8Scope())
 
 	auto consoleTemplate = ObjectTemplate::New();
 
-	Local<FunctionTemplate> function = FunctionTemplate::New(ConsoleLog, External::New(this));
-	consoleTemplate->Set(String::New("debug"), function);
-	consoleTemplate->Set(String::New("log"), function);
-	consoleTemplate->Set(String::New("error"), function);
+	Local<FunctionTemplate> consoleLog = FunctionTemplate::New(ConsoleLog, External::New(this));
+	consoleTemplate->Set(String::New("debug"), consoleLog);
+	consoleTemplate->Set(String::New("log"), consoleLog);
+	consoleTemplate->Set(String::New("error"), consoleLog);
 	context()->Global()->Set(String::New("console"), consoleTemplate->NewInstance());
+
+	Local<FunctionTemplate> loadScript = FunctionTemplate::New(LoadScript, External::New(this));
+	context()->Global()->Set(String::New("loadScript"), loadScript->GetFunction());
 }
 
 JSV8Engine::~JSV8Engine()
@@ -170,11 +204,11 @@ JSV8Engine::~JSV8Engine()
 	delete m_scope;
 }
 
-JSV8Value JSV8Engine::eval(char const* _cstr) const
+JSV8Value JSV8Engine::eval(char const* _cstr, char const* _origin) const
 {
 	TryCatch tryCatch;
 	Local<String> source = String::New(_cstr);
-	Local<String> name(String::New("(shell)"));
+	Local<String> name(String::New(_origin));
 	ScriptOrigin origin(name);
 	Handle<Script> script = Script::Compile(source, &origin);
 
diff --git a/libjsengine/JSV8Engine.h b/libjsengine/JSV8Engine.h
index 9d08d9b43..eb204c31e 100644
--- a/libjsengine/JSV8Engine.h
+++ b/libjsengine/JSV8Engine.h
@@ -54,7 +54,7 @@ class JSV8Engine: public JSEngine<JSV8Value>
 public:
 	JSV8Engine();
 	virtual ~JSV8Engine();
-	JSV8Value eval(char const* _cstr) const;
+	JSV8Value eval(char const* _cstr, char const* _origin = "(shell)") const;
 	v8::Handle<v8::Context> const& context() const;
 
 private: