#17 HABTM Checkboxes (revised)

I literally did this yesterday. I will finally subscribe just to see if we did it the same way.

Subscribing is totally worth it. I swear that last night I was literally looking on how to do this in Rails. Then bam. Next day here it is.

Using the hidden tag set to nil didn't work in my rails project. It might have to do with the fact that I'm using the Mongoid ODM. I found that unless all the values in the array are valid ids, nothing will change. (I suspect that ActiveRecord just ignores any non-valid values.)

To combat this issue, I set my hidden tag to a string like 'included'. Then in the controller, I used the line

params[:product][:category_ids].delete 'included'

I'm not sure if this is the best solution, but it works.

wow , i didnt know about dom_id, you know how many places have used interpolation instead?... :(

=D good thing i learned this , thanks Ryan.

How about following up with a series of screen-casts using Simple Form gem? I have used it in the past and the current project and find it extremely useful. Moreover, the PlataformaTec crew manning the Google Group is super helpful. I think a set of "Professional Screencasts" on Simple forms where you go deeper into the subject matter just as you did with z-shell will be very useful.
This screencast was great. Keep up the good work.
Bharat

Instead using <%= hidden_field_tag "product[category_ids][]", nil %> i used in my controller update action something like this:

params[:product] ||= {}
params[:product][:category_ids] ||= []

This works fine too! :)

When I use radios and checkboxes I generally wrap the input and text in a label tag. I like it because it increases the clickable area for a more comfortable UX. (http://dabblet.com/gist/1515022)

It's amazing how much I learned from this episode, for instance, I had no idea why we were submitting the hidden field for checkboxes; I also totally forgot about the dom_id method, and have been hacking id's together. I think I have some refactoring to do.

Thanks Ryan for an awesome year of Railcasts. Happy Holidays and all the best for the New Year!

Thanks for the amazing material. At $10 a month this is the most valuable development resource I've come across.

If anyone is having trouble getting the checkboxes to save make sure you make your assocation_ids accessible.

In my controller I have to add "@product.category_ids = params[:product][:category_ids]" to the create and update actions, otherwise nothing gets stored in the database. I don't see this in the source code of this episode. Am I forgetting something?

I'd like to see an example where categories and products are scoped through a current user. I'm trying to modify this example to scope things through a current_user and just can't seem to get it to work.
For example, in the form, I have:

<% current_user.categories.all.each do |category| %>

and in the controller, I have:

@product = current_user.products.new(params[:product])
if @product.save
etc...

The correct list of products is displayed on the form, but the save fails...

Is it actually safe to allow mass-assignment in this context?

Subscribed just for this episode so I do this the best way. Thanks!

I'm placing a comment onto this episode as it seems the most relevant.
Has anyone done a good example on the use of rails has_and_belongs_to_many, as i cannot think of a scenario in which i do not use has_many through: and i just cannot get my head around the habtm function...

As usual, this is a very handy example. However, I'm a bit confused. Why don't we need to use the "accept_nested_attributes_for" class method ?

Very helpful screencast. Thanks!

Thanks for this great screencast.

Got an issue with my app.

Checkboxes well diplayed, but when I update, got a message "Can't mass-assign protected attributes: group_ids"

So, I try to manage membership.

Got users and groups.

membership model :

class Membership < ActiveRecord::Base
  attr_accessible :created_at, :group_id, :position, :user_id
  
  belongs_to :group
  belongs_to :user
  
end

User model :

  attr_accessible :client_id, :email, :firstname, :group_id, :lastname, :password, :password_confirmation, :role_id
  has_many :memberships
  has_many :groups, :through => :memberships

Group model

  attr_accessible :name, :client_id, :description, :user_id
  
  has_many :memberships
  has_many :users, :through => :memberships

Here the code in my form

<%= hidden_field_tag "user[group_ids][]", nil %>
  <% Group.all.each do |group| %>
          <%= check_box_tag "user[group_ids][]", group.id, @user.group_ids.include?(group.id), id: dom_id(group) %>
          <%= label_tag dom_id(group), group.name %><br>
  <% end %>

Did I miss something ?

Thanks

Ok adding group_ids as attr_accessible in my User Model solve the problem !

Sorry :p

Exactly what I needed, subscribed to gain access to the revised versions, first for Revised 88 and now this one. Thank you so much!

Is there a way to display a text field when a checkbox is checked? Say you want to add more info about that product in the join model. You check "Board Game" and you want to comment that "Settlers of Catan is a great Board Game for ages 5 - Adult" (or something like that). You also check "Toys & Games" and want to add "A Great Christmas Gift". This would update a field in the join model table called "Comments". The data in the join model would now be

ID 1
product_id 1
category_id 1
comment "Settlers of Catan..."

ID 2
product_id 1
category_id 6
comment "A Great Christmas ..."

My question is, how do you store extra info in the join model and extract that out later?

Thanks.

With Rails 4 and strong parameters, if we want this to work, we have to add resource_ids: [] in the permit call. For example :

params[:user].permit(..., role_ids: [])

Am I right? It doesn't work if we just add :role_ids in the permit call, because it's an array and not a scalar.

I'm curious if this is the "right" approach for me to use for a particular portion of my application.

I have many tasks and many users. Tasks belong to a particular user, but can be completed by multiple users (defined by a manager role over another model).

Anyway, I want users to be able to opt-in/out of being reminded about certain tasks that they either own or manage.

My thought is to do a has_many :through relationship with a reminder join table.

My interface differs from the one in this railscast in that in the presentation of a task list, there would be just a single check box for each task that determines whether the current logged in user will get reminders for the task.

So I see lots of parallels to this railscast, but I can't seem to get to solution that doesn't feel cludgy. Am I on the right path?

Thanks!

'YAY THAT WORKS' - loving it! :)

Very helpful screencast! There are several Rails 4 helper methods for this and similar form building: https://github.com/rails/rails/blob/master/actionview/lib/action_view/helpers/form_options_helper.rb

Though doing it using Ryan's way allows for infinite flexibility.

Hi all,

I am trying to reproduce this approach using simple_form, but I am not sure how to recreate the check boxes using simple_form with all the features Ryan covered in this screencast.
Has anyone done this earlier?

Appreciate the help.

Xiao

I'm using Ruby 2.0 and Rails 3.2.8 and I can't seem to get the simple has_many through part working.
In my Event model

  attr_accessible :address1, :city, :country, :description, :enddate, :eventname, :startdate, :state, :status, :url, :zip, :eventcategory_ids
  has_many :categorizations
  has_many :categorizations
  has_many :event_categories, through: :categorizations 

In my Eventcategory model

  attr_accessible :description, :eventcategory, :event_id
  has_many :categorizations
  has_many :events, through: :categorizations 

In my Categorization model

  attr_accessible :created_at, :created_by, :event_id, :eventcategory_id
  belongs_to :event
  belongs_to :eventcategory

The tables are all there for all three models.

When I run: e = Event.first in the console it gets me my first event.
Then I run: e.eventcategory_ids I get: NoMethodError: undefined method 'eventcategory_ids' for #<Event:0x00000002b7d660>

I figure that has to work before any of the rest of the stuff from this screencast will work for me... right? Am I missing something here?

Not sure when Rails added this, but there's a much simpler way now:

<%= f.collection_check_boxes :category_ids, Category.all, :id, :name %>

amazing!

Friggin sweet.

I have error:
> ActiveRecord::RecordNotFound in UsersController#update
> Couldn't find all CategoryUsers with IDs (1, 3) (found 0 results, but was looking for 2)
Help me pleace

I have an odd case where my code created with the help of this rails casts for HABTM checkboxes was working fine... an then all of a sudden I'm getting a NoMethodError: undefined method `name' for nil:NilClass error when creating or updating a record that has project_ids filled in.

If I try to use the method in the rails console I get the error specifically at the point of adding project_id's like this:

p = Project.last

works and returns project field data

p.person_ids = [1,2]

1. runs 3 SQL statements, selecting the person, selecting through a join my assignment of the person to the project, and then inserting the assignment
2. then it says rollback transaction
3. and displays the method NoMethodError: undefined method `name' for nil:NilClas

And the weird part is, that once that all happens, if I call p.save after the errors list, it actually saves properly adding the two people assignments to the project

I've rolled back the git history to see if I did something else, but even if I go way back to previous versions that worked for sure it still gives the same error. This makes me think it's database related??

I have been trying to model a similar domain, but the price has to be on the join table, since the price is not known until purchased (think auction). I have read every post on the internet pertaining to has_many through with additional attributes on the join table and I am still not getting it.

I forked the repo https://github.com/jamlevi/017-habtm-checkboxes-revised and added a new folder "store-move-price-to-join". I added views/categories & controllers/categories_controller.rb. Using rails 3.2.17.

I realize this page/thread are pretty old, but I am hoping somebody out there sees this and can help me out (plus the same question is unanswered from 2 years ago). Pretty sure I need a fields_for in views/categories/_form.html & accepts_nested_attributes_for in category. A working repo would be tremendously helpful, instead of code snippets buried in many similar-but-not-same use case posts scattered throughout the intenet.