CODEWITHSUNDEEP
rubyruby-on-rails-3
simonmorley
simonmorley

Reputation: 2804

DateTime.parse within Rails Scope

I'm trying to convert a string to a time using DateTime.parse in a scope however, I'm getting an undefined local variable error.

Is it possible to convert a field within a scope or do I need to try something else?

My scope:

  scope :time_range, lambda {
    a = DateTime.parse(start_time_am)
    where("#{a} <= ?", Time.now.strftime('%H'))
  }

-- UPDATE --

Having played around with this, I've discovered I should probably overwrite the default accessor. I now have the following:

  def start_time_am
    read_attribute(:start_time_am).strftime("%H%M").to_i
  end

In the console, my start_time_am field now looks like:

 Promotion.last.start_time_am
  => 430

However, if I wanted to define a new field temporarily so I can still use the initial one.

I can access this in the console but not when searching. Eg.

   def start_time_new
     read_attribute(:start_time_am).strftime("%H%M").to_i
   end

  def self.time_range
    time = Time.now.strftime('%H%M').to_i
    where("start_time_new <= ?", time)
  end

Gives a unknown column error. I thought attr_reader would solve but it's not working.

Thanks

Upvotes: 0

Views: 1282

Answers (2)

simonmorley
simonmorley

Reputation: 2804

In the end, I did the conversion in the where statement and got rid of the virtual attributes:

def self.time_available
  where("cast(start_time as time) <= cast(now() as time) and cast(end_time as time) >= cast(now() as time)")
end

Hope that helps someone

Upvotes: 0

Simon Perepelitsa
Simon Perepelitsa

Reputation: 20639

If you rewrite this as an equivalent method definition then it might be easier to figure out.

def self.time_range
  a = DateTime.parse(start_time_am)
  where("#{a} <= ?", Time.now.strftime('%H'))
end

Where is start_time_am coming from? The method doesn't have any arguments.

Upvotes: 3

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