Hi there! I am still new to ruby/rails and there is a problem that looks rather trivial yet I am wondering what the neatest solution may be. I''d like the rows to be ordered "by hand", i.e. I''d like to allow the user to indicate the ordering of the rows (e.g. this goes after that, this goes first and so forth). As it happens, I am not a very experienced web developer and the only solution that comes to my mind is to use an integer column (e.g. named `position`) and when listing the rows to order by that column. However, there is the problem that this realization would require table locking: for instance if the user moves the 7th item to the beginning, the `position` indexes of all the first six rows would have to be modified (incremented by one to be precise). I''d be very grateful I anyone could propose some nice and very "rails-like" solution to my (I''d say rather) ordinary problem. Thank you very much! -- 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 May 15, 2010 7:52 PM, "Albus Dumbledore" <lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote: Hi there! I am still new to ruby/rails and there is a problem that looks rather trivial yet I am wondering what the neatest solution may be. I''d like the rows to be ordered "by hand", i.e. I''d like to allow the user to indicate the ordering of the rows (e.g. this goes after that, this goes first and so forth). As it happens, I am not a very experienced web developer and the only solution that comes to my mind is to use an integer column (e.g. named `position`) and when listing the rows to order by that column. However, there is the problem that this realization would require table locking: for instance if the user moves the 7th item to the beginning, the `position` indexes of all the first six rows would have to be modified (incremented by one to be precise). I''d be very grateful I anyone could propose some nice and very "rails-like" solution to my (I''d say rather) ordinary problem. Thank you very much! -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org<rubyonrails-talk%2Bunsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org> . For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en. -- 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.
Oops... pesky phone! Google for "acts_as_list" to sort this for you. On May 15, 2010 7:52 PM, "Albus Dumbledore" <lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote: Hi there! I am still new to ruby/rails and there is a problem that looks rather trivial yet I am wondering what the neatest solution may be. I''d like the rows to be ordered "by hand", i.e. I''d like to allow the user to indicate the ordering of the rows (e.g. this goes after that, this goes first and so forth). As it happens, I am not a very experienced web developer and the only solution that comes to my mind is to use an integer column (e.g. named `position`) and when listing the rows to order by that column. However, there is the problem that this realization would require table locking: for instance if the user moves the 7th item to the beginning, the `position` indexes of all the first six rows would have to be modified (incremented by one to be precise). I''d be very grateful I anyone could propose some nice and very "rails-like" solution to my (I''d say rather) ordinary problem. Thank you very much! -- 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-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org<rubyonrails-talk%2Bunsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org> . For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en. -- 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.
Michael Pavling wrote:> Oops... pesky phone! > > Google for "acts_as_list" to sort this for you.Thank you! I am googling it straight away! -- 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.
Michael Pavling wrote:> Oops... pesky phone! > > Google for "acts_as_list" to sort this for you.It seems you are quite correct - it is exactly what I needed. I am very grateful for this accurate and immediate response! Long live the ruby lang! -- 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.
Well. I am having trouble understanding how acts_as_list works. I do not
quite comprehend what the table schema for the example given by DHH must
be:
[code]
class TodoList < ActiveRecord::Base
has_many :todo_items, :order => "position"
end
class TodoItem < ActiveRecord::Base
belongs_to :todo_list
acts_as_list :scope => :todo_list
end
[/code]
More precisely I wonder where should the `position` column go? To me it
looks like it should go with the table having the foreign keys, i.e.
`todo_items` table. Then it would seem that there would be no need for a
`todo_lists` table, right? So it would be all about the todo_items
table.
Thank you!
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On May 16, 7:21 am, Albus Dumbledore <li...-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote:> More precisely I wonder where should the `position` column go? To me it > looks like it should go with the table having the foreign keys, i.e. > `todo_items` table.Correct - it is the items that are ordered with respect to each other.> Then it would seem that there would be no need for a > `todo_lists` table, right? So it would be all about the todo_items > table.You could conceivably do that (and have the todo_list_id just being an identifier for splitting the items into different lists rather than a foreign key), but in most use cases you''d want to track some per list information (for example who created it, the name of the list etc.) Fred -- 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.
Hi, What you need is to watch a Railscast: http://media.railscasts.com/videos/147_sortable_lists.mov It will explain all you need and save you hours of work. On May 16, 6:21 am, Albus Dumbledore <li...-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote:> Well. I am having trouble understanding how acts_as_list works. I do not > quite comprehend what the table schema for the example given by DHH must > be: > > [code] > > class TodoList < ActiveRecord::Base > has_many :todo_items, :order => "position" > end > > class TodoItem < ActiveRecord::Base > belongs_to :todo_list > acts_as_list :scope => :todo_list > end > > [/code] > > More precisely I wonder where should the `position` column go? To me it > looks like it should go with the table having the foreign keys, i.e. > `todo_items` table. Then it would seem that there would be no need for a > `todo_lists` table, right? So it would be all about the todo_items > table. > > Thank you! > -- > Posted viahttp://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@googlegroups.com. > For more options, visit this group athttp://groups.google.com/group/rubyonrails-talk?hl=en.-- 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.
Thank you Fred! Most instructive. Riccardo Tacconi wrote:> Hi, > > What you need is to watch a Railscast: > http://media.railscasts.com/videos/147_sortable_lists.mov > > It will explain all you need and save you hours of work.Thank you Riccardo! Indeed I have watched this railscast. It is quite practical. However, there was nothing much said about using `acts_as_list`. -- 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 16 May 2010 13:07, Albus Dumbledore <lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote:> Thank you Fred! Most instructive. > > Riccardo Tacconi wrote: >> Hi, >> >> What you need is to watch a Railscast: >> http://media.railscasts.com/videos/147_sortable_lists.mov >> >> It will explain all you need and save you hours of work. > > Thank you Riccardo! Indeed I have watched this railscast. It is quite > practical. However, there was nothing much said about using > `acts_as_list`.There is not a great deal more to say, what else do you want to know? Colin -- 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.
Colin Law wrote:> There is not a great deal more to say, what else do you want to know? > > ColinIt''s scope that is bothering me. Firstly we can have our rows grouped by a foreign key (which seems trivial enough). However, what happens if it is a polymorphic reference, i.e. we need to use two columns to select a unique row? It is very kind of all those people bothering to answer such trivial questions as mine. Thank you! -- 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 16 May, 16:46, Albus Dumbledore <li...-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote:> > It''s scope that is bothering me. Firstly we can have our rows grouped > by a foreign key (which seems trivial enough). However, what happens if > it is a polymorphic reference, i.e. we need to use two columns to select > a unique row? >Scope can be a string in which case you can include more stuff or you can override the scope_condition method - have a nose around in the source code for acts as list Fred -- 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.
I will! Thanks Fred. -- 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 16 May 2010 06:21, Albus Dumbledore <lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org> wrote:> Well. I am having trouble understanding how acts_as_list works. I do not > quite comprehend what the table schema for the example given by DHH must > be: > > [code] > > class TodoList < ActiveRecord::Base > has_many :todo_items, :order => "position" > end > > class TodoItem < ActiveRecord::Base > belongs_to :todo_list > acts_as_list :scope => :todo_list > end > > [/code] > > More precisely I wonder where should the `position` column go? To me it > looks like it should go with the table having the foreign keys, i.e. > `todo_items` table. Then it would seem that there would be no need for a > `todo_lists` table, right? So it would be all about the todo_items > table.Yes; the position column goes on the table you want ordered. The purpose of the todo_list table is to allow there to be more than one list of items (if you want one). The "scope" field is a way of identifying what separates the lists in the items table. So if every user needs a list, then you can scope by user; if you''re only having one list of the items, then there''s no need for a scope - just position.> It''s scope that is bothering me. Firstly we can have our rows grouped > by a foreign key (which seems trivial enough). However, what happens if > it is a polymorphic reference, i.e. we need to use two columns to select > a unique row?Right.... your posting is suffering a little "feature creep" at the moment. If you post what the limits are of the real problem you have, then people can suggest solutions. If you have a complicated data structure, then post some of the model code so we can all get our heads around it.> > Thank you! > -- > 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@googlegroups.com. > For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en. > >-- 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.