call JavaScript functions from Ruby

History.txt

@@ -1,3 +1,6 @@
+=== Edge
+* 1 major enhancement
+  * call JavaScript functions from Ruby
 === 0.6.0 2010-03-31
 * 4 major enhancements
   * ruby 1.9 compatible

ext/v8/converters.cpp

@@ -3,6 +3,7 @@
 #include "v8_ref.h"
 #include "v8_obj.h"
 #include "v8_cxt.h"
+#include "v8_func.h"
 #include "v8_template.h"
 
 using namespace v8;
@@ -16,6 +17,7 @@ VALUE V8_To;
 VALUE V82RB(Handle<Value>& value) {
   convert_v8_to_rb_t convert;
   VALUE result;
+  VALUE type = V8_C_Object;
   if(convert(value, result)) {
     return result;
   }
@@ -30,18 +32,21 @@ VALUE V82RB(Handle<Value>& value) {
     return rb_array;
   }
   
+  if (value->IsFunction()) {
+    type = V8_C_Function;
+  }
+
   if (value->IsObject()) {
     Local<Object> object(Object::Cast(*value));
     Local<Value> peer = object->GetHiddenValue(String::New("TheRubyRacer::RubyObject"));
     if (peer.IsEmpty()) {
       VALUE context_ref = V8_Ref_Create(V8_C_Context, Context::GetCurrent());
       object->SetHiddenValue(String::New("TheRubyRacer::Context"), External::Wrap((void *)context_ref));
-      return V8_Ref_Create(V8_C_Object, value, context_ref);
+      return V8_Ref_Create(type, value, context_ref);
     } else {      
       return (VALUE)External::Unwrap(peer);
     }
   }
-  
   return Qnil;
 }
 

ext/v8/v8.cpp

@@ -86,5 +86,6 @@ extern "C" {
         
         
         V8_C_Function = rb_define_class_under(rb_mNative, "Function", V8_C_Object);
+        rb_define_method(V8_C_Function, "Call", (VALUE(*)(...))v8_C_Function_Call, -1);
     }
 }

ext/v8/v8_func.cpp

@@ -1,4 +1,5 @@
 
+#include "converters.h"
 #include "v8_func.h"
 
 using namespace v8;
@@ -8,3 +9,20 @@ VALUE V8_C_Function;
 VALUE V8_Wrap_Function(Handle<Function> f) {
   return V8_Ref_Create(V8_C_Function, f);
 }
+
+
+VALUE v8_C_Function_Call(int argc, VALUE *argv, VALUE self) {
+  HandleScope handles;
+  VALUE recv; VALUE f_argv;
+  rb_scan_args(argc, argv, "1*", &recv, &f_argv);
+
+  Local<Function> function = V8_Ref_Get<Function>(self);
+  Local<Object> thisObject(Object::Cast(*RB2V8(recv)));
+  int f_argc = argc - 1;
+  Local<Value> arguments[f_argc];
+  for (int i = 0; i < f_argc; i++) {
+    arguments[i] = RB2V8(rb_ary_entry(f_argv,i));
+  }
+  Local<Value> result = function->Call(thisObject, f_argc, arguments);
+  return V82RB(result);
+}

ext/v8/v8_func.h

@@ -8,4 +8,6 @@
 extern VALUE V8_C_Function;
 
 VALUE V8_Wrap_Function(v8::Handle<v8::Function> f);
+
+VALUE v8_C_Function_Call(int argc, VALUE *argv, VALUE self);
 #endif

lib/v8.rb

@@ -7,5 +7,6 @@ module V8
   require 'v8/to'
   require 'v8/context'
   require 'v8/object'
+  require 'v8/function'
   require 'v8/tap'
 end

lib/v8/function.rb

@@ -0,0 +1,9 @@
+module V8
+  class Function < V8::Object
+    
+    def call(thisObject, *args)
+      To.ruby(@native.Call(To.v8(thisObject), *args.map {|a| To.v8(a)}))
+    end
+    
+  end
+end

lib/v8/to.rb

@@ -4,8 +4,9 @@ module V8
     class << self
       def ruby(value)
         case value
-        when V8::C::Object then V8::Object.new(value)
-        when V8::C::String then "Wonkers!"          
+        when V8::C::Function  then V8::Function.new(value)
+        when V8::C::Object    then V8::Object.new(value)
+        when V8::C::String    then "Wonkers!"
         else
           value
         end

spec/ext/func_spec.rb

@@ -0,0 +1,42 @@
+require "#{File.dirname(__FILE__)}/../spec_helper.rb"
+
+include V8
+
+describe C::Function do
+  it "is callable" do
+    C::Context.new.open do |cxt|
+      f = cxt.eval('(function() {return "Hello World"})', '<eval>');      
+      f.Call(cxt.Global).should == "Hello World"      
+    end
+  end
+  
+  it "receives proper argument length from ruby" do
+    C::Context.new.open do |cxt|
+      f = cxt.eval('(function() {return arguments.length})', 'eval')
+      f.Call(nil,1, 2, 3).should == 3
+    end
+  end
+  
+  it "maps all arguments from ruby" do
+    C::Context.new.open do |cxt|
+      f = cxt.eval('(function(one, two, three) {return one + two + three})', 'eval')
+      f.Call(nil, 1,2,3).should == 6
+    end
+  end
+  
+  it "properly maps ruby objects back and forth from arguments to return value" do
+    C::Context.new.open do |cxt|
+      Object.new.tap do |this|
+         f = cxt.eval('(function() {return this})', 'eval')
+         f.Call(this).should be(this)
+      end
+    end
+  end 
+  
+  it "can be called outside of a context" do
+    C::Context.new.open do |cxt|
+      @f = cxt.eval('(function() {return "Call Me"})', 'eval')
+    end
+    @f.Call(nil).should == "Call Me"
+  end
+end