Getting the 'Sender' or 'Caller' object of a method

ruby-talk
1

Hi,

I am not having much luck in finding out how to get the calling object
of a method.

Is there an implicit way that a method can get a pointer to the object
that called it, or do I have to write that explicitly, manually
including a 'sender' parameter for the method call myself?

I have looked at 'caller' but can only coax a string out of it.

Thanks in advance for your kind help!

- Nex

···

--
Posted via http://www.ruby-forum.com/.

2

Depends on what you want to do. If it's for debugging purposes you
can use set_trace_func to keep track of callers or just trace the
whole program execution.

If you need it for your program logic then you should pass the caller
- either as method parameter or set it as an attribute before the
call. Depends on what you do which is more appropriate.

Kind regards

robert

···

2007/8/3, Peter Laurens <peterlaurenspublic@gmail.com>:

Hi,

I am not having much luck in finding out how to get the calling object
of a method.

Is there an implicit way that a method can get a pointer to the object
that called it, or do I have to write that explicitly, manually
including a 'sender' parameter for the method call myself?

I have looked at 'caller' but can only coax a string out of it.

3

Hmm maybe binding_of_caller might help, as far as I know Facet
implements it, and Why did so too, maybe just google it, I would not
know which one to recommend.

HTH
Robert

···

On 8/3/07, Peter Laurens <peterlaurenspublic@gmail.com> wrote:

Hi,

I am not having much luck in finding out how to get the calling object
of a method.

Is there an implicit way that a method can get a pointer to the object
that called it, or do I have to write that explicitly, manually
including a 'sender' parameter for the method call myself?

I have looked at 'caller' but can only coax a string out of it.

Thanks in advance for your kind help!

- Nex
--
Posted via http://www.ruby-forum.com/\.

--
[...] as simple as possible, but no simpler.
-- Attributed to Albert Einstein

4

Peter Laurens wrote:

I am not having much luck in finding out how to get the calling object
of a method.

I'm not sure to understand what you mean, because inside a method
"meth", which is used/called by an object "obj" by "obj.meth", the
object can be referenced by "self".

Wolfgang Nádasi-Donner

···

--
Posted via http://www.ruby-forum.com/\.

5

in many contexts this will work:

require 'binding_of_caller'

def method
   caller = Binding_of_caller{|binding| eval 'self', binding}
end

notably NOT class methods though...

a @ http://drawohara.com/

···

On Aug 3, 2007, at 7:19 AM, Peter Laurens wrote:

Hi,

I am not having much luck in finding out how to get the calling object
of a method.

Is there an implicit way that a method can get a pointer to the object
that called it, or do I have to write that explicitly, manually
including a 'sender' parameter for the method call myself?

I have looked at 'caller' but can only coax a string out of it.

Thanks in advance for your kind help!

- Nex
-- Posted via http://www.ruby-forum.com/\.

--
we can deny everything, except that we have the possibility of being better. simply reflect on that.
h.h. the 14th dalai lama

6

Thanks to the both of you - it appears as though my best way to do this
is just manually then, via a passed 'sender' parameter.

Thanks!

- Nex

···

--
Posted via http://www.ruby-forum.com/.

7

You can always take a block and get the binding from it:

  def method(&b)
    callers_binding = b.send(:binding)
  end

I works always. Yes, it means passing a block, but sometimes that's
useful anyway.

T.

···

On Aug 3, 9:59 am, "ara.t.howard" <ara.t.how...@gmail.com> wrote:

On Aug 3, 2007, at 7:19 AM, Peter Laurens wrote:

> Hi,

> I am not having much luck in finding out how to get the calling object
> of a method.

> Is there an implicit way that a method can get a pointer to the object
> that called it, or do I have to write that explicitly, manually
> including a 'sender' parameter for the method call myself?

> I have looked at 'caller' but can only coax a string out of it.

> Thanks in advance for your kind help!

> - Nex
> --
> Posted viahttp://www.ruby-forum.com/.

in many contexts this will work:

require 'binding_of_caller'

def method
   caller = Binding_of_caller{|binding| eval 'self', binding}
end

notably NOT class methods though...

8

IIRC, binding of caller hasn't worked since 1.8.4. It relied on a bug
that was fixed.

Ben

···

On Fri, Aug 03, 2007, Robert Dober wrote:

Hmm maybe binding_of_caller might help, as far as I know Facet
implements it, and Why did so too, maybe just google it, I would not
know which one to recommend.

9

My mistake, I was thinking of Binding#of_caller, which was a different
thing, heh.

Ben

···

On Sat, Aug 04, 2007, Ben Bleything wrote:

On Fri, Aug 03, 2007, Robert Dober wrote:
> Hmm maybe binding_of_caller might help, as far as I know Facet
> implements it, and Why did so too, maybe just google it, I would not
> know which one to recommend.

IIRC, binding of caller hasn't worked since 1.8.4. It relied on a bug
that was fixed.

10

??

cfp:~ > cat a.rb
def a &b
   eval 'self', b.send(:binding)
end

require 'binding_of_caller'
def b
   Binding.of_caller{|binding| eval 'self', binding}
end

p self
p a
p b

cfp:~ > ruby a.rb
main
nil
main

cfp:~ > ruby -v
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.9.1]

am i misunderstanding?

a @ http://drawohara.com/

···

On Aug 3, 2007, at 11:50 AM, Trans wrote:

  You can always take a block and get the binding from it:

  def method(&b)
    callers_binding = b.send(:binding)
  end

I works always. Yes, it means passing a block, but sometimes that's
useful anyway.

--
we can deny everything, except that we have the possibility of being better. simply reflect on that.
h.h. the 14th dalai lama

11

yup, Tom asks us to kindly pass him a block

p a {}

one could consider it cheating, but it is incredibly useful, I did not
know about it.

Thx and Cheers
Robert

···

On 8/3/07, ara.t.howard <ara.t.howard@gmail.com> wrote:

On Aug 3, 2007, at 11:50 AM, Trans wrote:

> You can always take a block and get the binding from it:
>
> def method(&b)
> callers_binding = b.send(:binding)
> end
>
> I works always. Yes, it means passing a block, but sometimes that's
> useful anyway.
>

??

cfp:~ > cat a.rb
def a &b
   eval 'self', b.send(:binding)
end

require 'binding_of_caller'
def b
   Binding.of_caller{|binding| eval 'self', binding}
end

p self
p a
p b

cfp:~ > ruby a.rb
main
nil
main

cfp:~ > ruby -v
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.9.1]

am i misunderstanding?

--
[...] as simple as possible, but no simpler.
-- Attributed to Albert Einstein

12

ah. i mis-read that. it *is* very useful. thanks.

a @ http://drawohara.com/

···

On Aug 3, 2007, at 1:46 PM, Robert Dober wrote:

one could consider it cheating, but it is incredibly useful, I did not
know about it.

--
we can deny everything, except that we have the possibility of being better. simply reflect on that.
h.h. the 14th dalai lama