Could someone explain why this code does not work in ruby1.9 and
possibly provide a workaround. The end goal is to be able to pass a
binding to an ERb result method that provides a limited set of
variables to the ERb template evaluation.
cat a.rb
obj = Object.new
class << obj
attr_accessor :foo
end
obj.foo = ‘the foo method’
eval “puts foo”, obj.send(:binding)
ruby a.rb
the foo method
ruby1.9 a.rb
a.rb:7:in eval': undefined local variable or methodfoo’ for
main:Object (NameError)
from a.rb:7:in eval' from a.rb:7:in’
ruby1.9 --version
ruby 1.9.1p0 (2009-01-30 revision 21907) [i386-darwin9.6.0]
Blessings,
TwP
Tim P. wrote:
end
obj.foo = ‘the foo method’
eval “puts foo”, obj.send(:binding)
What an unusual feature to keep coming up.
The contract of binding is that it returns a reification of the caller’s
binding. Under 1.8, however, the behavior acted a bit differently, using
the “self” that binding was actually called against. 1.9 has largely
remedied this by always returning the binding of the caller, even if you
send(:binding) to another object.
I believe instance_evaling “binding” against the target object would
give you the behavior you’re looking for:
[headius @ cnutter:~/projects/ruby-benchmark-suite]
â—† ruby -e “o = Object.new; p o; eval ‘p self’, o.send(:binding)”
#Object:0x29414
#Object:0x29414
[headius @ cnutter:~/projects/ruby-benchmark-suite]
â—† ruby1.9 -e “o = Object.new; p o; eval ‘p self’, o.send(:binding)”
#Object:0x3e736c
main
[headius @ cnutter:~/projects/ruby-benchmark-suite]
â—† ruby1.9 -e “o = Object.new; p o; eval ‘p self’,
o.instance_eval{binding}”
#Object:0x3e72a4
#Object:0x3e72a4
On Jan 30, 2009, at 12:56 PM, Charles Oliver N. wrote:
obj.foo = ‘the foo method’
Okay, that explanation makes sense. My new implementation (following
along with the Kernel docs)
cat a.rb
obj = Object.new
class << obj
attr_accessor :foo
def get_binding() binding; end
end
obj.foo = ‘the foo method’
eval “puts foo”, obj.get_binding
ruby1.9 a.rb
the foo method
Thanks for the insight.
Blessings,
TwP