Generic method without case/when?


#1

I like to write a generic method that calls different functions
depending on
what string I parse to the method (see example) without having to use a
case-when? Is there a way to do that?

Process_easy(“aFile”, “Summer”)

def process_easy(file, what)

if file.include?("#{what}#{NL}") then
  constructor = CategoriesFactory.start_what # this is wrong. I like 

to
substitute and have: constructor = CategoriesFactory.start_summer
start = file.index(“Summer#{NL}”)
return constructor

etc

end

-Bernd


#2

Paatsch, Bernd wrote:

substitute and have: constructor = CategoriesFactory.start_summer
start = file.index(“Summer#{NL}”)
return constructor

etc

end

-Bernd

Check the Object#send method:

obj.send(‘method’, arg1, arg2…)


#3

Paatsch, Bernd wrote:

like to substitute and have: constructor =
CategoriesFactory.start_summer start = file.index(“Summer#{NL}”)
return constructor

etc

end

Difficult to tell from this example. You could use send as Tim
suggested.
But you might as well use a different approach:

  • extract a class name from the string
  • extract another string from the string and map that via a Hash to a
    lambda / class whatever

MAP = {
“what” => lambda {|x| puts “doing what #{x}”},
“Summer” => lambda {|x| puts “it’s summer”},
}
def process_easy(file)
cmd = MAP[file[/\w+$/m]] and cmd[file]
end

Kind regards

robert