Given one model with a more complex sort in it. @products = Product.all If I now have the ID of a product that is in @products - what is the best way to find the previous/next element (keeping the model sort in mind, e.g. the previous / next with respect to the custom sort, not with respect to the database)? Is there a better way than stepping through using .each? -- 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 Wed, Jan 5, 2011 at 5:28 AM, bourne <bourne7-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> Given one model with a more complex sort in it. > @products = Product.all > > If I now have the ID of a product that is in @products - what is the best > way to find the previous/next element (keeping the model sort in mind, e.g. > the previous / next with respect to the custom sort, not with respect to the > database)? Is there a better way than stepping through using .each?@products is just an Array; you should look through the doc to see the methods available. You might find Array#index and Array#at of interest. :-) HTH, -- Hassan Schroeder ------------------------ hassan.schroeder-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org twitter: @hassan -- 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.
Hassan Schroeder wrote in post #972525:> @products is just an Array; you should look through the doc to see > the methods available. You might find Array#index and Array#at of > interest. :-)In other words. A Ruby Array (@products.class => Array) is an ordered list, as opposed to Hash or Set, which store unordered collections of objects. So if you order the records from a fetch such as: @products = Product.order(:name) The Array will maintain the objects in the order specified in the query. And getting next or previous is just as Hassan explained: product = @products.at(3) next_product = product.index(@products.index(product) +1) Note. Don''t forget to check the array bounds or you might get unexpected results. -- 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.
Thanks for the pointer to .at.
For the archives:
@product_before = ''tablehead''
@productindex = @products.index(@product)
if @productindex
if @productindex > 0
@product_before = ''product_'' +
@products.at(@productindex -
1).id.to_s
end
end
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