Question

I’m currently trying to DRY up this initial verbose code:

def planting_dates_not_nil?     !plant_out_week_min.blank? || !plant_out_week_max.blank? || !sow_out_week_min.blank? || !sow_out_week_max.blank?   end    def needs_planting?(week)     if !plant_out_week_min.blank? && !plant_out_week_max.blank?       (plant_out_week_min..plant_out_week_max).include? (week)      end   end    def needs_sowing?(week)     if !sow_out_week_min.blank? && !sow_out_week_max.blank?       (sow_out_week_min..sow_out_week_max).include? (week)     end    end    def needs_harvesting?(week)     if !harvest_week_min.blank? && !harvest_week_max.blank?       (harvest_week_min..harvest_week_max).include? (week)      end   end 

here’s my intial attempt:

  def tasks_for_week(week,*task_names)     task_names.each do |task_name|       to_do_this_week = []         unless read_attribute(task_name).nil?           if (read_attribute('#{task_name}_week_min')..read_attribute('#{task_name}_week_max')).include? (week)             to_do_this_week << task_name           end         end       end   end 

However, when I run this code in the console as follows:

p.tasks_for_week(Date.today.cweek, :plant_out, :sow_out]) 

I get an unexpected result…even though the plant does not need to be planted out, I still get an array of both task names returned ( [:plant_out, :sow_out]

Can anyone let me know how I’d clean this up and have the tasksforweek method return the expected results?

TIA

Answer 1

Your method is returning the result of task_names.each. each always returns what it started with. So you need to actually return your result.

Also, you are recreating you to_do_this_week array on every iteration of the loop, which would wipe it clean.

def tasks_for_week(week, *task_names)   to_do_this_week = []   task_names.each do |task_name|     if some_condition       to_do_this_week << task_name      end   end   to_do_this_week end 

Or this:

def tasks_for_week(week, *task_names)   returning [] do |to_do_this_week|     task_names.each do |task_name|       if some_condition         to_do_this_week << task_name        end     end   end end 

But I think this is probably your best best:

def tasks_for_week(week, *task_names)   task_names.find_all do |task_name|     some_condition   end end 

That last one uses find_all which iterates over an array and will return a new array populated with any objects that the block return a true value for.

Lastly, your conditional logic is a bit crazy too. You can use the [] accessors for active record fields in a dynamic way. And it’s usually clearer to use the positive case instead of the double negative of unless something.nil?. And if this is a common use for creating a range, it might be best to farm that out to a method:

def week_range_for_task(task)   self['#{task_name}_week_min']..self['#{task_name}_week_max'] end  ...  self[task_name] && week_range_for_task(task_name).include?(week) 

Making the whole method:

def tasks_for_week(week, *task_names)   task_names.find_all do |task_name|     self[task_name] && week_range_for_task(task_name).include?(week)   end end