[Ironruby-core] Problem with using OpenStruct and ERB

Nathan Standiford nstandif at live.com
Fri Jun 22 17:44:29 UTC 2012


Yeah, that seems like it was the problem. I fixed it by defining the getter
method directly in the object I was running the ERB file in. 

require "erb"
def eval_field(field)
  field.each do |key, value|
    class << self; self; end.class_eval do
      define_method(key) { @field[key] }
    end
  end
  @field = field
  binding
end

ERB.new("<%= foo %>").result(eval_field({:foo => "bar"})

I find it odd that OpenStruct won't work, despite this code almost being
almost identical to that of OpenStruct.

From: ironruby-core-bounces at rubyforge.org
[mailto:ironruby-core-bounces at rubyforge.org] On Behalf Of Orion Edwards
Sent: Tuesday, June 19, 2012 4:20 PM
To: ironruby-core at rubyforge.org
Subject: Re: [Ironruby-core] Problem with using OpenStruct and ERB

Ahh I see. 

I don't have a copy of 1.8.6 handy to test on, but this definitely fails for
MRI 1.9. 
It seems like getting the binding of an ostruct in 1.9 doesn't work for
evaluating local variables. Perhaps they changed ostruct? 

Here's what happens for me: 

irb(main):020:0> ostruct = OpenStruct.new({:foo => 'bar'}) 
=> #<OpenStruct foo="bar"> 
irb(main):021:0> ostruct_binding = ostruct.send(:binding) 
=> #<Binding:0x2545dd0> 
irb(main):022:0> eval("foo", ostruct_binding) 
NameError: undefined local variable or method `foo' for main:Object 

IronRuby 1.1 aims for compatibility with ruby 1.9 (and ships standard
libraries such as ostruct from 1.9 also), so it is designed to fail with the
same errors as MRI 1.9 

I'm not sure what you can do to work around it, all the best. 


______________________________________________________

Orion Edwards | Technical Leader 
PHONE +64 7 838 9800 | FAX +64 7 838 9801 | 
EMAIL orion.edwards at gallagher.co | WEB www.gallagher.co  



From:        Nathan Standiford <nstandif at live.com> 
To:        <ironruby-core at rubyforge.org> 
Date:        20/06/2012 10:53 a.m. 
Subject:        Re: [Ironruby-core] Problem with using OpenStruct and ERB 
Sent by:        ironruby-core-bounces at rubyforge.org 
________________________________________



I am trying to send the binding of the OpenStruct object not the binding of
main.  I have been using this with MRI 1.8.6 for some time and works fine. 
  
From: ironruby-core-bounces at rubyforge.org
[mailto:ironruby-core-bounces at rubyforge.org] On Behalf Of Orion Edwards
Sent: Tuesday, June 19, 2012 2:23 PM
To: ironruby-core at rubyforge.org
Subject: Re: [Ironruby-core] Problem with using OpenStruct and ERB 
  
I notice that in your example, you don't declare the local variable foo
anywhere: 
If I run it verbatim, both MRI and IronRuby fail with undefined method foo
(and fair enough, foo isn't defined). 
When I declare foo as a local variable, both MRI and IronRuby work fine for
me. 

______________________________________________________

Orion Edwards | Technical Leader 
PHONE +64 7 838 9800 | FAX +64 7 838 9801 | 
EMAIL orion.edwards at gallagher.co | WEB www.gallagher.co   



From:        Nathan Standiford <nstandif at live.com> 
To:        <ironruby-core at rubyforge.org> 
Date:        20/06/2012 04:55 a.m. 
Subject:        [Ironruby-core] Problem with using OpenStruct and ERB 
Sent by:        ironruby-core-bounces at rubyforge.org 

________________________________________




I am using OpenStructs and ERB for template generation. In this simple
example, ruby 1.8.6 runs this fine: 
require "erb" 
require "ostruct" 
puts ERB.new("<%=foo%>", 0, "%<>").result(OpenStruct.new({ :foo => "bar"
}).send(:binding)) 
 
However, it generates the following error when I run this in IronRuby
1.1.3.0 on .NET 4.0.30319.269: 
(erb):2: undefined method `foo' for main:Object (NoMethodError) 
 
Does anyone know how to get this to behave correctly in IronRuby? 
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