Refactor question

Hi,

I’m trying to refactor some code…

  if session[:image_subject_id].blank?
    if @profile.image_subject_id.blank?
      session[:image_subject_id] = nil
    else
      session[:image_subject_id] = @profile.image_subject_id
    end
  end

  if session[:image_subject_id].blank?
    if @profile.image_book_id.blank?
      session[:image_book_id]  = nil
    else
      session[:image_book_id] = @profile.image_book_id
    end
  end
   ...
   ...
   ...

Trying the following:

[“image_subject_id”, “image_book_id”, “image_chapter_id”,
“image_section_id”“image_subsection_id”, “image_minisection_id”].each do
|k|

      if session[":#{k.to_s}"].blank?
        if @profile.k.blank?
          session[":#{k.to_s}"] = nil
        else
          session[":#{k.to_s}"] = @profile.k
        end
      end

end

Problem is @profile.k gives error NoMethodError: undefined method `k’
for #Profile:0x00000106da5e60

k does evaluate to “image_subject_id”, so not sure what is wrong…

Thanks

On 10 May 2014 03:46, Dave C. [email protected] wrote:


Trying the following:

[“image_subject_id”, “image_book_id”, “image_chapter_id”,
“image_section_id”“image_subsection_id”, “image_minisection_id”].each do
|k|

      if session[":#{k.to_s}"].blank?

I don’t see why you need .to_s as k should already be a string

        if @profile.k.blank?

Use send to invoke a method (actually send a message) using a string
if @profile.send(k).blank?

          session[":#{k.to_s}"] = nil
        else
          session[":#{k.to_s}"] = @profile.k
        end
      end

end

However no doubt someone will come up with a much better way of
accomplishing the whole thing.

Colin

Colin L. wrote in post #1145636:

On 10 May 2014 03:46, Dave C. [email protected] wrote:

Use send to invoke a method (actually send a message) using a string
if @profile.send(k).blank?

Thanks Colin.

lauantai, 10. toukokuuta 2014 11.21.24 UTC+3 Colin L. kirjoitti:

      if session[":#{k.to_s}"].blank?

I don’t see why you need .to_s as k should already be a string

It doesn’t even matter, since the hash syntax within a string calls
.to_s
implicitly:

irb(main):026:0> “1234 #{:foo} 232”
=> “1234 foo 232”

Anyway, you won’t even need to change the symbols to strings:

[:image_subject_id, :image_book_id, :image_chapter_id,
:image_section_id, :image_subsection_id, :image_minisection_id].each do
|k|

      if session[k].blank?
        if @profile.send(k).blank?
          session[k] = nil
        else
          session[k] = @profile.send(k)
        end
      end

end

That said, do you even need to check for the corner cases like that?
Since
you’re talking about ids, I would assume they can only be nil or a valid
id. So would this be sufficient (inside the loop):

session[k] ||= @profile.send(k)

If you do have to e.g. take empty strings (with which .blank? is true)
into
account, then something like this perhaps?

      if session[k].blank?
        session[k] = (val = @profile.send(k)).blank? ? nil : val
      end

//jarkko

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