# Setting up global variables when hosting IronRuby in CLR

**URL:** <https://www.ruby-forum.com/t/setting-up-global-variables-when-hosting-ironruby-in-clr/207225>\
**Category:** IronRuby\
**Created:** [May 20, 2011, 9:36pm UTC](https://www.ruby-forum.com/t/setting-up-global-variables-when-hosting-ironruby-in-clr/207225 "2011-05-20T21:36:08Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [May 20, 2011, 9:36pm UTC](https://www.ruby-forum.com/t/setting-up-global-variables-when-hosting-ironruby-in-clr/207225/1 "2011-05-20T21:36:08Z")

</div>

How to setup global variables in CLR that could be accessed by scripts  
running in Iron Ruby engine hosted in CLR.

Some posts referred to the API Runtime.GetCurrentExecutionContext and  
then setting up global variables there but in IronRuby version 1.1.3  
this API is missing.

Ruby Script code (Test.rb):  
class Test  
def DoSomething()  
puts “Value of global variable is #{$gVar}”  
end  
end

C# code:  
// setup runtime etc  
engine = runtime.GetEngine(“IronRuby”);

// setup global variables  
// something like gVar = “Hello IronRuby”  
scriptSource = engine.CreateScriptSourceFromFile(scriptFile)  
scriptSource.Execute()

object myType = engine.Runtime.Globals.GetVariable(“Test”);  
// Create a class instance  
object myTypeObj = engine.Operations.CreateInstance(myType);  
// Execute method  
object result = engine.Operations.InvokeMember(myTypeObj,  
“doSomething”);

Any help is greatly appreciated.

Thank you,  
Ramesh

---

<div class="post-metadata">

**Author:** ![ramesh\_n](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/9f8e36/32.png) [@ramesh\_n](https://www.ruby-forum.com/u/ramesh_n)\
**Post date:** [May 22, 2011, 12:06am UTC](https://www.ruby-forum.com/t/setting-up-global-variables-when-hosting-ironruby-in-clr/207225/2 "2011-05-22T00:06:20Z")

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Ramesh,

You can still access RubyContext through  
Microsoft.Scripting.Hosting.Providers.HostingHelpers.GetLanguageContext.  
The following extension method adds the old API back … if you need  
it:

```
public static class IronRubyExtensions {
    public static RubyContext GetExecutionContext(this

```

ScriptEngine engine) {  
return HostingHelpers.GetLanguageContext(engine) as  
RubyContext;  
}  
}

Then setting a global variable from C# is:

```
engine.GetExecutionContext().DefineGlobalVariable("gVar", 42);

```

That being said, this API isn’t final and may change in future  
versions of the DLR. If you rather use an API that is more final, and  
you still _really_ need to set a global variable, you could do it by  
actually executing Ruby code:

```
dynamic scope = engine.CreateScope();
scope.gVar = 42
engine.Execute("$gVar = gVar", scope);

```

Now to the address my “if you need it” comments:  
Ruby.GetExecutionContext(ScriptEngine) was removed from IronRuby 1.0  
as we didn’t want to promote an hosting-level API that is  
language-specific. Also, because it’s main usage is for setting global  
variables (since there is no DLR-level API for Ruby globals), we felt  
comfortable about introducing this breaking change as using Ruby  
global variables is not a recommended practice (see  
[http://www.rubyist.net/~slagell/ruby/globalvars.html](http://www.rubyist.net/~slagell/ruby/globalvars.html)).

~Jimmy