How to build a record of a many_to_many relation with a form?










0














Say, I have two model in a many to many relationship (without additional attributes), so a simple has_and_belongs_to_many relationship.



For the purpose, let's say I have a user model and a course model.And the corresponding join table courses_users has only the foreign keys user_id and course_id as attributes.



Now I'm listing (say in the show page of the user) all the course and according to if the current user has enrolled or not (i.e. if a record exist in the join table) I display a cross ✘ or a check ✔.

No problem thus far.



The problem is that I'm unable to make it editable in a form.



I mean how can I associate a form checkbox with the fact that if it is checked I build a relation, and if not I delete it?



Thank you very much.




Here is my simple models:



class User < ApplicationRecord
has_and_belongs_to_many :courses
end

class Course < ApplicationRecord
has_and_belongs_to_many :users
end


And here is my form attempt but I don't know at all what to do next.

I thought about checking for the foreign key of the course..



<%= form_with model: @user do |form| %>
<%= @courses.each do |course| %>
<%= form.fields_for :courses do |ff| %>
<%= ff.check_box 'course_id', checked: (@user.courses.include? course.id) %>
<%= ff.label 'course_id' %>
<% end %>
<% end %>
<%= form.submit %>
<% end %>









share|improve this question

















  • 1




    see Cocoon Gem, best for nested forms. You can dynamically add and remove nested form elements.
    – Sikandar Tariq
    Nov 13 '18 at 7:06











  • Thanks I'll take a look.. But I would want to know how to handle that with regular rails...
    – SanjiBukai
    Nov 13 '18 at 7:32










  • by looking at your problem I think you'll need JQuery/Javascript to achieve the required functionality... and the gem I referred will do exactly the same (will provide JQuery implementation for this)
    – Sikandar Tariq
    Nov 13 '18 at 7:48










  • I thought that this is not something related to the client side. I mean if I could built that form correctly with rails forms or if I can have the "data" built by some JS.. I'll just get some kind of structured params.. But I'll still need a way to understand that params and build according relationships in the controller.
    – SanjiBukai
    Nov 13 '18 at 8:14















0














Say, I have two model in a many to many relationship (without additional attributes), so a simple has_and_belongs_to_many relationship.



For the purpose, let's say I have a user model and a course model.And the corresponding join table courses_users has only the foreign keys user_id and course_id as attributes.



Now I'm listing (say in the show page of the user) all the course and according to if the current user has enrolled or not (i.e. if a record exist in the join table) I display a cross ✘ or a check ✔.

No problem thus far.



The problem is that I'm unable to make it editable in a form.



I mean how can I associate a form checkbox with the fact that if it is checked I build a relation, and if not I delete it?



Thank you very much.




Here is my simple models:



class User < ApplicationRecord
has_and_belongs_to_many :courses
end

class Course < ApplicationRecord
has_and_belongs_to_many :users
end


And here is my form attempt but I don't know at all what to do next.

I thought about checking for the foreign key of the course..



<%= form_with model: @user do |form| %>
<%= @courses.each do |course| %>
<%= form.fields_for :courses do |ff| %>
<%= ff.check_box 'course_id', checked: (@user.courses.include? course.id) %>
<%= ff.label 'course_id' %>
<% end %>
<% end %>
<%= form.submit %>
<% end %>









share|improve this question

















  • 1




    see Cocoon Gem, best for nested forms. You can dynamically add and remove nested form elements.
    – Sikandar Tariq
    Nov 13 '18 at 7:06











  • Thanks I'll take a look.. But I would want to know how to handle that with regular rails...
    – SanjiBukai
    Nov 13 '18 at 7:32










  • by looking at your problem I think you'll need JQuery/Javascript to achieve the required functionality... and the gem I referred will do exactly the same (will provide JQuery implementation for this)
    – Sikandar Tariq
    Nov 13 '18 at 7:48










  • I thought that this is not something related to the client side. I mean if I could built that form correctly with rails forms or if I can have the "data" built by some JS.. I'll just get some kind of structured params.. But I'll still need a way to understand that params and build according relationships in the controller.
    – SanjiBukai
    Nov 13 '18 at 8:14













0












0








0







Say, I have two model in a many to many relationship (without additional attributes), so a simple has_and_belongs_to_many relationship.



For the purpose, let's say I have a user model and a course model.And the corresponding join table courses_users has only the foreign keys user_id and course_id as attributes.



Now I'm listing (say in the show page of the user) all the course and according to if the current user has enrolled or not (i.e. if a record exist in the join table) I display a cross ✘ or a check ✔.

No problem thus far.



The problem is that I'm unable to make it editable in a form.



I mean how can I associate a form checkbox with the fact that if it is checked I build a relation, and if not I delete it?



Thank you very much.




Here is my simple models:



class User < ApplicationRecord
has_and_belongs_to_many :courses
end

class Course < ApplicationRecord
has_and_belongs_to_many :users
end


And here is my form attempt but I don't know at all what to do next.

I thought about checking for the foreign key of the course..



<%= form_with model: @user do |form| %>
<%= @courses.each do |course| %>
<%= form.fields_for :courses do |ff| %>
<%= ff.check_box 'course_id', checked: (@user.courses.include? course.id) %>
<%= ff.label 'course_id' %>
<% end %>
<% end %>
<%= form.submit %>
<% end %>









share|improve this question













Say, I have two model in a many to many relationship (without additional attributes), so a simple has_and_belongs_to_many relationship.



For the purpose, let's say I have a user model and a course model.And the corresponding join table courses_users has only the foreign keys user_id and course_id as attributes.



Now I'm listing (say in the show page of the user) all the course and according to if the current user has enrolled or not (i.e. if a record exist in the join table) I display a cross ✘ or a check ✔.

No problem thus far.



The problem is that I'm unable to make it editable in a form.



I mean how can I associate a form checkbox with the fact that if it is checked I build a relation, and if not I delete it?



Thank you very much.




Here is my simple models:



class User < ApplicationRecord
has_and_belongs_to_many :courses
end

class Course < ApplicationRecord
has_and_belongs_to_many :users
end


And here is my form attempt but I don't know at all what to do next.

I thought about checking for the foreign key of the course..



<%= form_with model: @user do |form| %>
<%= @courses.each do |course| %>
<%= form.fields_for :courses do |ff| %>
<%= ff.check_box 'course_id', checked: (@user.courses.include? course.id) %>
<%= ff.label 'course_id' %>
<% end %>
<% end %>
<%= form.submit %>
<% end %>






ruby-on-rails database forms activerecord nested






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asked Nov 13 '18 at 2:59









SanjiBukaiSanjiBukai

19513




19513







  • 1




    see Cocoon Gem, best for nested forms. You can dynamically add and remove nested form elements.
    – Sikandar Tariq
    Nov 13 '18 at 7:06











  • Thanks I'll take a look.. But I would want to know how to handle that with regular rails...
    – SanjiBukai
    Nov 13 '18 at 7:32










  • by looking at your problem I think you'll need JQuery/Javascript to achieve the required functionality... and the gem I referred will do exactly the same (will provide JQuery implementation for this)
    – Sikandar Tariq
    Nov 13 '18 at 7:48










  • I thought that this is not something related to the client side. I mean if I could built that form correctly with rails forms or if I can have the "data" built by some JS.. I'll just get some kind of structured params.. But I'll still need a way to understand that params and build according relationships in the controller.
    – SanjiBukai
    Nov 13 '18 at 8:14












  • 1




    see Cocoon Gem, best for nested forms. You can dynamically add and remove nested form elements.
    – Sikandar Tariq
    Nov 13 '18 at 7:06











  • Thanks I'll take a look.. But I would want to know how to handle that with regular rails...
    – SanjiBukai
    Nov 13 '18 at 7:32










  • by looking at your problem I think you'll need JQuery/Javascript to achieve the required functionality... and the gem I referred will do exactly the same (will provide JQuery implementation for this)
    – Sikandar Tariq
    Nov 13 '18 at 7:48










  • I thought that this is not something related to the client side. I mean if I could built that form correctly with rails forms or if I can have the "data" built by some JS.. I'll just get some kind of structured params.. But I'll still need a way to understand that params and build according relationships in the controller.
    – SanjiBukai
    Nov 13 '18 at 8:14







1




1




see Cocoon Gem, best for nested forms. You can dynamically add and remove nested form elements.
– Sikandar Tariq
Nov 13 '18 at 7:06





see Cocoon Gem, best for nested forms. You can dynamically add and remove nested form elements.
– Sikandar Tariq
Nov 13 '18 at 7:06













Thanks I'll take a look.. But I would want to know how to handle that with regular rails...
– SanjiBukai
Nov 13 '18 at 7:32




Thanks I'll take a look.. But I would want to know how to handle that with regular rails...
– SanjiBukai
Nov 13 '18 at 7:32












by looking at your problem I think you'll need JQuery/Javascript to achieve the required functionality... and the gem I referred will do exactly the same (will provide JQuery implementation for this)
– Sikandar Tariq
Nov 13 '18 at 7:48




by looking at your problem I think you'll need JQuery/Javascript to achieve the required functionality... and the gem I referred will do exactly the same (will provide JQuery implementation for this)
– Sikandar Tariq
Nov 13 '18 at 7:48












I thought that this is not something related to the client side. I mean if I could built that form correctly with rails forms or if I can have the "data" built by some JS.. I'll just get some kind of structured params.. But I'll still need a way to understand that params and build according relationships in the controller.
– SanjiBukai
Nov 13 '18 at 8:14




I thought that this is not something related to the client side. I mean if I could built that form correctly with rails forms or if I can have the "data" built by some JS.. I'll just get some kind of structured params.. But I'll still need a way to understand that params and build according relationships in the controller.
– SanjiBukai
Nov 13 '18 at 8:14












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