Has a method been called?

ruby-talk
1

Hi,
Is it possible to find out if a method has been called except by adding
a flag to it?

class Whatever
  @flag = 0

  def method_called
    @flag += 1
  end

  def has_method_been_called
    false
    return true if @flag > 0
  end

end

Cheers

Aidy

2

Have a look at set_trace_func. It's documented in the pickaxe book
online at http://www.rubycentral.com/book/ospace.html (just scroll
down to Tracing Your Program's Execution). You'll probably be
interested in the 'call' events.

Farrel

···

On 07/09/06, aidy <aidy.rutter@gmail.com> wrote:

Hi,
Is it possible to find out if a method has been called except by adding
a flag to it?

class Whatever
  @flag = 0

  def method_called
    @flag += 1
  end

  def has_method_been_called
    false
    return true if @flag > 0
  end

end

Cheers

Aidy

3

If it's enough for you to know that off-line, you can use rcov or
ruby-prof for that. Run rcov and see whether it's code was visited. If
you need to know in the runtime, that's another story :wink:

···

On 9/7/06, aidy <aidy.rutter@gmail.com> wrote:

Hi,
Is it possible to find out if a method has been called except by adding
a flag to it?

class Whatever
  @flag = 0

  def method_called
    @flag += 1
  end

  def has_method_been_called
    false
    return true if @flag > 0
  end

end

Cheers

Aidy

4

You can also whip up a little meta programming mess (warning thrown
together, collision causing, not thread safe code follows):

class Module

  def flag_use(sym)
    self.instance_eval do
      define_method "#{sym}_called?" do
        false
      end

      flag_name = "use_flagged_#{sym}".to_sym
      alias_method flag_name, sym
      define_method sym do
        self.class.instance_eval do
          alias_method sym, flag_name
          define_method "#{sym}_called?" do
            true
          end
        end
        flag_name
      end
    end
  end
end

Then...

class Foo
  def bar
    puts :bar
  end
  flag_use :bar
end

f = Foo.new
p f.bar_called?
f.bar
p f.bar_called?

pth

···

On 9/7/06, Jan Svitok <jan.svitok@gmail.com> wrote:

On 9/7/06, aidy <aidy.rutter@gmail.com> wrote:
> Hi,
> Is it possible to find out if a method has been called except by adding
> a flag to it?
>
> class Whatever
> @flag = 0
>
> def method_called
> @flag += 1
> end
>
> def has_method_been_called
> false
> return true if @flag > 0
> end
>
> end
>
> Cheers
>
> Aidy

If it's enough for you to know that off-line, you can use rcov or
ruby-prof for that. Run rcov and see whether it's code was visited. If
you need to know in the runtime, that's another story :wink:

5

You can do it with rcov's API:

RUBY_VERSION # => "1.8.5"
require 'rcov'
class Foo;
  def foo; 1 end
  def bar; 1 end
end

analyzer = Rcov::CallSiteAnalyzer.new
analyzer.run_hooked do
  f = Foo.new
  f.foo
end

def analyzer.executed?(selector); !!defsite(selector) end

analyzer.executed? "Foo#foo" # => true
analyzer.executed? "Foo#bar" # => false

However, in this case I'd rather intercept the method call, record it and
redispatch (standard alias_method/module_eval idiom, or define_method if the
redefined methods take no blocks or you're using Ruby 1.9).

···

On Fri, Sep 08, 2006 at 12:23:10AM +0900, Jan Svitok wrote:

On 9/7/06, aidy <aidy.rutter@gmail.com> wrote:
>class Whatever
> @flag = 0
>
> def method_called
> @flag += 1
> end
>
> def has_method_been_called
> false
> return true if @flag > 0
> end
>
>end

If it's enough for you to know that off-line, you can use rcov or
ruby-prof for that. Run rcov and see whether it's code was visited. If
you need to know in the runtime, that's another story :wink:

--
Mauricio Fernandez - http://eigenclass.org - singular Ruby