I want to set the values of several record fields from within an
iterator where the field name is passed as a parameter. For example
(conceptually):
# Line numbers are for reference only and are not a part of the code.
1. record=Model.find(id)
2. params.each do |key,value|
3. eval(''record.''+key)=value
4. end
Apparently, having the eval on the LHS of an assignment doesn''t work.
Can anyone please tell me what would work?
Thanks for any input.
... doug
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Doug Jolley wrote:> I want to set the values of several record fields from within an > iterator where the field name is passed as a parameter. For example > (conceptually): > > # Line numbers are for reference only and are not a part of the code. > 1. record=Model.find(id) > 2. params.each do |key,value| > 3. eval(''record.''+key)=value > 4. end > > Apparently, having the eval on the LHS of an assignment doesn''t work. > Can anyone please tell me what would work?record[key] = value Note that this relies on the hash-like behavior of ActiveRecord. If you wanted to do this with a non-AR object, you could use record.send("#{key}=", value). eval is rarely necessary in Ruby. However, in this case, you could just do record.update_attributes(params).> > Thanks for any input. > > ... doug > > -- >Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
On Mon, Dec 21, 2009 at 1:23 PM, doug <ddjolley-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> I want to set the values of several record fields from within an > iterator where the field name is passed as a parameter. For example > (conceptually): > > # Line numbers are for reference only and are not a part of the code. > 1. record=Model.find(id) > 2. params.each do |key,value| > 3. eval(''record.''+key)=value > 4. end > > Apparently, having the eval on the LHS of an assignment doesn''t work. > Can anyone please tell me what would work?First of all if you are doing this from a controller, you probably don''t want to use ALL of the parameters, but only those for the model, probably coming from a form, For an active record model you can do: # Assuming that the model really is called Model, and you are following Rails conventions for the form: model_params = params[:model] || [] model_params.each do |key, value| record[key] = value end or just record.attributes=(model_params, false) The false overrides the protection of attributes, and probably isn''t a good idea in general. You normally don''t want to blindly mass assign any attributes the user throws at you. Consider the fact that the incoming url might be coming from a form submission from your app, or might be forged. -- Rick DeNatale Blog: http://talklikeaduck.denhaven2.com/ Twitter: http://twitter.com/RickDeNatale WWR: http://www.workingwithrails.com/person/9021-rick-denatale LinkedIn: http://www.linkedin.com/in/rickdenatale -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
Wow, two really thorough answers. Thanks so much. Sorry for the
delay in responding. I wanted to see if I couldn''t get this thing
working before responding; but, alas, I ran into other problems.
However, I would have to say that this issue has definitely been put
to bed. Thanks for the input.
Oh, BTW:
# Assuming that the model really is called Model,
It isn''t. I chose that name for illustrative purposes.
Thanks to all for the input.
... doug
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