Getting initialization status from "foo = Class.new"

Ruby
1

Here’s a ruby noob question for ya:

I have a class I’ve made that the initalize method searches for a file
needed for the class to function.

Right now, I’ve made a class variable, “found”, that is set to true or
false if the initialize method could or could not find the file.

For example:

foo = Class.new

if foo.found == true

continue program

else

give error message

exit

Is there a way for “Class.new” to signal failure? I originally had the
class’s initialize method return true or false but this doesn’t seem to
be reflected in a “foo = Class.new” when trying it in irb.

Using the class variable “found” works but shouldn’t Class.new signal
failure?

2

On 11/13/06, Rodney B. [email protected] wrote:

Is there a way for “Class.new” to signal failure? I originally had the
class’s initialize method return true or false but this doesn’t seem to
be reflected in a “foo = Class.new” when trying it in irb.

Using the class variable “found” works but shouldn’t Class.new signal
failure?

How about raising an exception?
http://www.rubycentral.com/book/tut_exceptions.html

-Harold

3

Rodney B. wrote:

foo = Class.new

Using the class variable “found” works but shouldn’t Class.new signal
failure?

Generally when the initialize method fails it should raise an exception.

4

Hi, Rodney,

   I wrote a small program for you, maybe it can meet your

requirements.
I think you intended that your program flow could be controled directly
by
“foo = Class.new” instead of other dedicated variables like “@found”
for
this purpose.
//////////////////////program commences///////////////////////
class ClassAndFileTest
def initialize
puts “shiwei zhang”;
#searching the file…
#if found the file
;
#if did not find the file
raise “file not found!”;
end
end

begin
foo=ClassAndFileTest.new;
rescue
#give error message
puts $!;
exit;
end
# continue program
puts “file found!”;
…
/////////////////////////program concludes////////////////////////////

Rgds,
Shiwei