Get the caller of a class

Ruby
1

I have something like:

Class MyClass
def doit

caller= How can I do it

puts 'I was called from: ' + caller.class
puts 'the value of the @variab is: ' + caller.variab.to_s()

end
end

Class MyCaller
attr_reader: :variab
attr_writer: :variab

def callit
@variab=“example”
result=MyClass.doit
end
end

Is there any way to do it??

Thank you

2

Sorry the code was wrong, it should be:

class MyClass
def MyClass.doit

caller= How can I do it

puts 'I was called from: ' + caller.class.to_s()
puts 'the value of the @variab is: ' + caller.variab.to_s()

end
end

class MyCaller
attr_reader :variab
attr_writer :variab

def initialize
puts ‘starts’
end
def callit
@variab=“example”
result=MyClass.doit
end
end

MyCaller.new().callit

3

2008/8/1 Mario R. removed_email_address@domain.invalid:

There is no such thing as the “caller of a class”: a class can be used
by many clients and only methods are actually “called”. “caller” is
actually already defined. See whether this helps:

15:19:02 bas$ irb
Ruby version 1.8.7
irb(main):001:0> def a(n) b(n) end
=> nil
irb(main):002:0> def b(n) caller(n) end
=> nil
irb(main):003:0> 3.times {|i| puts i, a(i), “----”}
0
(irb):2:in b' (irb):1:in a’
(irb):4:in irb_binding' (irb):4:in times’
(irb):4:in irb_binding' /usr/lib/ruby/1.8/irb/workspace.rb:52:in irb_binding’
/usr/lib/ruby/1.8/irb/workspace.rb:52

1
(irb):1:in a' (irb):4:in irb_binding’
(irb):4:in times' (irb):4:in irb_binding’
/usr/lib/ruby/1.8/irb/workspace.rb:52:in `irb_binding’
/usr/lib/ruby/1.8/irb/workspace.rb:52

2
(irb):4:in irb_binding' (irb):4:in times’
(irb):4:in irb_binding' /usr/lib/ruby/1.8/irb/workspace.rb:52:in irb_binding’
/usr/lib/ruby/1.8/irb/workspace.rb:52

=> 3

Kind regards

robert

4

This is profoundly unhelpful, I know: but perhaps you should consider
redesigning your method so that it doesn’t care where it was called
from? That would be more in line with Object Oriented design.

You might find that it belongs on another class, for example the
parent class of all the classes that you are currently considering
calling it from.

Or you could leave it where it is and pass some sort of mode string,
instead:

def doit(mode)
case mode
when :full then …
when :quick then …
end
end

On 8/1/08, Robert K. removed_email_address@domain.invalid wrote:

irb(main):002:0> def b(n) caller(n) end

(irb):4:in `times’

–
use.inject do |as, often| as.you_can - without end

–
Me, I imagine places that I have never seen / The colored lights in
fountains, blue and green / And I imagine places that I will never go
/ Behind these clouds that hang here dark and low
But it’s there when I’m holding you / There when I’m sleeping too /
There when there’s nothing left of me / Hanging out behind the
burned-out factories / Out of reach but leading me / Into the
beautiful sea

5

2008/8/1 removed_email_address@domain.invalid:

This is profoundly unhelpful, I know: but perhaps you should consider
redesigning your method so that it doesn’t care where it was called
from? That would be more in line with Object Oriented design.

Good point! After rereading the original posting I would suggest the
same. Just pass on the calling instance or the bit of data that the
method needs. That’s what method arguments are for.

Kind regards

robert

6

I know that way… but I would like to know if it is possible to do it
without passing the argument to the method. :slight_smile:

7

On Fri, Aug 1, 2008 at 10:25 PM, Mario R. removed_email_address@domain.invalid wrote:

I know that way… but I would like to know if it is possible to do it
without passing the argument to the method. :slight_smile:

try #caller

botp@jedi-hopeful:~$ qri caller
---------------------------------------------------------- Kernel#caller
caller(start=1) => array

 Returns the current execution stack---an array containing strings
 in the form ``file:line'' or ``file:line: in `method'''. The
 optional start parameter determines the number of initial stack
 entries to omit from the result.

    def a(skip)
      caller(skip)
    end
    def b(skip)
      a(skip)
    end
    def c(skip)
      b(skip)
    end
    c(0)   #=> ["prog:2:in `a'", "prog:5:in `b'", "prog:8:in `c'",

“prog:10”]
c(1) #=> [“prog:5:in b'", "prog:8:in c’”, “prog:11”]
c(2) #=> [“prog:8:in `c’”, “prog:12”]
c(3) #=> [“prog:13”]

hth.
kind regards -botp

8

Thanks to everybody.

I thought it could be an easier way to do it so I’ll just pass a ‘self’
parameter.

Thanks.

9

Mario, there once was a library called binding_of_caller, which I
think could do what you wanted, but I think it doesn’t work anymore
with recent Ruby versions.

Regards,
Pit