How to loop rails variable?

Question

I have totally nine buttons in rails. I have input the data into the database by manually typing the @button_1.save function.

My question is:

How can i have the @button_i.save function in rails? I have finished the things in the for loop, what is left is the button save functions.

Many thanks!

      button_number = params[:button_number]

      for i in (1..button_number)
         instance_variable_set("@button#{i}", 
                               Button.new(:title => params["button_title_#{i}".to_sym], 
                               :order => i, 
                               :icon_url => params["button_icon_#{i}".to_sym], 
                               :navigation_id => @navigation.id, 
                               :next_navigation => params["selected_navigation_#{i}".to_sym].to_i, 
                               :next_page => params["selected_page_#{i}".to_sym].to_i))
         instance_variable_set("@button#{i}")
      end

      @button1.save
      @button2.save
      @button3.save
      @button4.save
      @button5.save
      @button6.save

may you post your error.

Ganesh Kunwar
– Ganesh Kunwar

2013-01-16 07:29:32 +00:00
Commented Jan 16, 2013 at 7:29 — Ganesh Kunwar
– Ganesh Kunwar, Commented Jan 16, 2013 at 7:29

Valery Kvon · Accepted Answer · 2013-01-16 07:41:09Z

2

for i in ...
  eval("@button#{i}.save")
end

answered Jan 16, 2013 at 7:41

Valery Kvon

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Comments

accounted4 · Accepted Answer · 2013-01-16 08:13:47Z

2

The opposite of instance_variable_set is instance_variable_get, which I think will lead you to the correct answer:

1.upto(params[:button_number].to_i) do |i|
  instance_variable_set("@button#{i}", 
    Button.new(
      :title => params["button_title_#{i}".to_sym], 
      :order => i, 
      :icon_url => params["button_icon_#{i}".to_sym], 
      :navigation_id => @navigation.id, 
      :next_navigation => params["selected_navigation_#{i}".to_sym].to_i, 
      :next_page => params["selected_page_#{i}".to_sym].to_i
    )
  )
  instance_variable_get("@button#{i}").save
end

edited Jan 16, 2013 at 8:13

answered Jan 16, 2013 at 7:41

accounted4

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1 Comment

George Jor Over a year ago

i add .to_i to the params and make it correct. thanks! params[:button_number].to_i

Ganesh Kunwar · Accepted Answer · 2013-01-16 07:44:21Z

0

Try by using constantize ruby function because I think your function call statement is in string.

button_number = params[:button_number]

      for i in (1..button_number)
         instance_variable_set("@button#{i}", 
                               Button.new(:title => params["button_title_#{i}".to_sym], 
                               :order => i, 
                               :icon_url => params["button_icon_#{i}".to_sym], 
                               :navigation_id => @navigation.id, 
                               :next_navigation => params["selected_navigation_#{i}".to_sym].to_i, 
                               :next_page => params["selected_page_#{i}".to_sym].to_i))
        "@button#{i}".constantize.save();
      end

edited Jan 16, 2013 at 7:44

answered Jan 16, 2013 at 7:27

Ganesh Kunwar

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2 Comments

George Jor Over a year ago

how to use the constantize function?

Ganesh Kunwar Over a year ago

you can use constanize function in function call statement

sjain · Accepted Answer · 2013-01-16 07:47:23Z

-1

May be this that you want -

button_number = params[:button_number].to_i

for i in (1..button_number)
             instance_variable_set("@button#{i}", 
                                   Button.new(:title => params["button_title_#{i}".to_sym], 
                                   :order => i, 
                                   :icon_url => params["button_icon_#{i}".to_sym], 
                                   :navigation_id => @navigation.id, 
                                   :next_navigation => params["selected_navigation_#{i}".to_sym].to_i, 
                                   :next_page => params["selected_page_#{i}".to_sym].to_i))
             instance_variable_set("@button#{i}")

      "@button#{i}".save

      end

edited Jan 16, 2013 at 7:47

answered Jan 16, 2013 at 7:30

sjain

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4 Comments

George Jor Over a year ago

thanks man, but it shows "bad value for range", how to deal with it?

sjain Over a year ago

this is because the params[:button_number] that you are getting is an object and not a number. Please check my updated post above.

sjain Over a year ago

good to know that the solution worked. :) but did eval solved it too as you accepted that as a answer and in below post you commented that .to_i to the params made it correct.?

George Jor Over a year ago

ya, the problem is the .to_i affect the most

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