I am using simple_form, a known Rails gem that makes the forms a little bit easier. I am having trouble to edit the forms. I can save the records perfectly, but when I go to the edit action, I don't see the records of the nested object from the database.
Models
# app/models/user.rb
has_one :member
has_one :academic, through: :member
accepts_nested_attributes_for :member, reject_if: :all_blank
# app/models/member.rb
belongs_to :user
has_one academic, dependent: :delete
accepts_nested_attributes_for academic, allow_destroy: true, reject_if: :all_blank
# app/models/academic.rb
belongs_to :member
Controller
# app/controllers/member_controller.rb
def edit
#member = Member.find(params[:id])
#academic = Academic.find_by_member_id(params[:id])
#member.build_academic
#member.academic.build_exchange_student # ExchangeStudent belongs_to :academic also
end
View
# app/views/_form.html.erb partial on app/views/edit.html.erb
<%= simple_form_for #member, url: database_members_path do |f| %>
<%= f.fields_for :academic do |academic_exchange_student| %>
<%= academic_exchange_student.fields_for :exchange_student do |exchange| %>
<!-- ##### Exchange student -->
<div class="row">
<%= academic_exchange_student.text_field :major%>
</div>
<% end %>
<% end %>
Yes, I am permitting the ids in the params.require(...). The record is saved perfectly, I can see it in the rails console.
When I go to this edit page, I can see the information of the member already in the text_field, but I don't see the information of the #member.academic.major there.
Also, if I go to the edit page and return in the browser, the academic record is deleted mysteriously.
Any help will be appreciated. Thank you.
I guess the problem here is that you build a new academic object in the edit view, and there can only be one academic in your User model.
I would suggest you to build the new academic only if it does not exist already:
def edit
#member = Member.find(params[:id])
#member.build_academic unless #member.academic
#member.academic.build_exchange_student unless #member.academic.exchange_student
end
PS: you also don't need the #academic variable, unless it's not used somewhere else in the edit view.
Related
I have a pretty basic Rails 4 app, and am using Cocoon's nested forms to manage the has_many... :through model association.
class Student < ActiveRecord::Base
has_many :evaluations
has_many :assessments, through: :evaluations
# ... etc
end
class Evaluation < ActiveRecord::Base
belongs_to :student
belongs_to :assessment
# ... etc
end
class Assessment < ActiveRecord::Base
has_many :evaluations
has_many :students, through: :evaluations
accepts_nested_attributes_for :evaluation, reject_if: :all_blank
# ... etc
end
When I use Cocoon in the View, I want to use the New Assessment view to pre-fill all the Student records in order to create a new Evaluation for each one. I don't want to have to do some hacky logic on the controller side to add some new records manually, so how would I structure the incoming request? With Cocoon I see that requests have some number in the space where the id would go (I've replaced these with ?? below).
{"utf8"=>"✓", "authenticity_token"=>"whatever", "assessment"=>{"description"=>"quiz 3", "date(3i)"=>"24", "date(2i)"=>"10", "date(1i)"=>"2015", "assessments_attributes"=>{"??"=>{"student_id"=>"2", "grade" => "A"}, "??"=>{"student_id"=>"1", "grade" => "B"}, "??"=>{"student_id"=>"3", "grade"=>"C"}}, }}, "commit"=>"Create Assessment"}
I see in the Coccoon source code that this is somehow generated but I can't figure out how it works with the Rails engine to make this into a new record without an ID.
What algorithm should I use (or rules should I follow) to fill in the id above to make a new record?
"??"
Never a good sign in your params.
With Cocoon I see that requests have some number in the space where the id would go
That ID is nothing more than the next ID in the fields_for array that Rails creates. It's not your record's id (more explained below).
From your setup, here's what I'd do:
#app/models/student.rb
class Student < ActiveRecord::Base
has_many :evaluations
has_many :assessments, through: :evaluations
end
#app/models/evaluation.rb
class Evaluation < ActiveRecord::Base
belongs_to :student
belongs_to :assessment
end
#app/models/assessment.rb
class Assessment < ActiveRecord::Base
has_many :evaluations
has_many :students, through: :evaluations
accepts_nested_attributes_for :evaluations, reject_if: :all_blank
end
This will allow you to do the following:
#app/controllers/assessments_controller.rb
class AssessmentsController < ApplicationController
def new
#assessment = Assessment.new
#students = Student.all
#students.each do
#assessment.evaluations.build
end
end
end
Allowing you:
#app/views/assessments/new.html.erb
<%= form_for #assessment do |f| %>
<%= f.fields_for :evaluations, #students do |e| %>
<%= e.hidden_field :student_id %>
<%= e.text_field :grade %>
<% end %>
<%= f.submit %>
<% end %>
As far as I can tell, this will provide the functionality you need.
Remember that each evaluation can connect with existing students, meaning that if you pull #students = Student.all, it will populate the fields_for accordingly.
If you wanted to add new students through your form, it's a slightly different ballgame.
Cocoon
You should also be clear about the role of Cocoon.
You seem like an experienced dev so I'll cut to the chase - Cocoon is front-end, what you're asking is back-end.
Specifically, Cocoon is meant to give you the ability to add a number of fields_for associated fields to a form. This was discussed in this Railscast...
Technically, Cocoon is just a way to create new fields_for records for a form. It's only required if you want to dynamically "add" fields (the RailsCast will tell you more).
Thus, if you wanted to just have a "static" array of associative data fields (which is I think what you're asking), you'll be able to use fields_for as submitted in both Max and my answers.
Thanks to #rich-peck I was able to figure out exactly what I wanted to do. I'm leaving his answer as accepted because it was basically how I got to my own. :)
assessments/new.html.haml (just raw, no fancy formatting)
= form_for #assessment do |f|
= f.fields_for :evaluations do |ff|
.meaningless-div
= ff.object.student.name
= ff.hidden_field :student_id, value: ff.object.student_id
= ff.label :comment
= ff.text_field :comment
%br/
assessments_controller.rb
def new
#assessment = Assessment.new
#students = Student.all
#students.each do |student|
#assessment.evaluations.build(student: student)
end
end
I have 2 models dog and litter_field:
class Dog < ActiveRecord::Base
belongs_to :user
has_one :litter_field
accepts_nested_attributes_for :litter_field
attr_accessible :litter_field_attributes
end
class LitterField < ActiveRecord::Base
belongs_to :dog
attr_accessible :breed_type
end
In my controller I have:
class DogsController < ApplicationController
def edit
#dog = Dog.find(params[:id])
#dog.build_litter_field
end
And in my view I have:
<%= simple_form_for #dog do |f| %>
<%= f.fields_for :litter_field do |l| %>
<div>
<%= l.label :breed_type %>
<%= l.input_field :breed_type %>
</div>
<%= f.button :submit, "Save" %>
<% end %>
I've looked at the documentation and from what I can tell this should work, however this page is not on the main edit page which I'm assuming is where the problem lies. Should I be adding what's in the edit action to a new action which displays the litter_field edit form?
EDIT:
What I am trying to do is split the edit form into separate pages, I've done this by adding additional actions that render extra pages so a user would go to dogs/settings/litter for example to see the litter_field nested form. I've tried adding #dog.build_litter_field to the litter action which displays the fields but when I try and save the form I am getting the error:
Failed to remove the existing associated litter_field. The record failed to save when after its foreign key was set to nil.
EDIT 2:
Fixed the above with adding:
has_one :litter_field, :dependent => :destroy
accepts_nested_attributes_for :litter_field, update_only: true
To dog.rb, the only problem I have now is it won't display the saved value on edit.
If you call #dog.build_litter_field in the edit action, it will build a new LitterField overtop of whatever had been saved previously. I would suggest trying something like this to see if it solves the problem you are currently seeing:
def edit
#dog = Dog.find(params[:id])
#dog.build_litter_field if #dog.litter_field.nil?
end
It can also help to checkout the debugger gem. You can use that to step through controller actions and see what the objects look like after each statement.
I'm trying to build a form_for to create a join model between two other models. I have a Book model and User model, with another called Reads that is my join. Here is how I've set up the associations:
class User < ActiveRecord::Base
has_many :reads
has_many :books, :through => :reads
end
class Book < ActiveRecord::Base
has_many :reads
has_many :users, :through => :reads
end
class Read < ActiveRecord::Base
belongs_to :book
belongs_to :user
end
I've looked at the docs for form_for and watched the railscast episode on many-to-many associations, but I can't figure out why I'm getting the error when I try to render the Book#show view where I've put the form:
First argument in form cannot contain nil or be empty
Here is my form in app/views/books/show.html.erb:
<%= form_for(#read) do |f| %>
<%= f.hidden_field :book_id, value: #book.id %>
<%= button_to 'Add to Reads', {controller: 'reads', action: 'create'}, {class: 'btn'} %>
<% end %>
I think part of the problem is that I am trying to create a 'Reads' object from the Books model, but I'm not sure what I am doing wrong. I need the 'Add to Reads' button on the Book's page so that a user can select that particular book to add to their 'reads.' I'm also adding the current_user id in the controller, rather than in the view. Here is my create action from the Reads controller if that helps...
def create
#read = Read.new(read_params)
#read.user_id = current_user.id
#read.save
if #read.save
# do this
else
# do that
end
end
And I'm using strong params...
def read_params
params.require(:read).permit(:user_id, :book_id)
end
Thanks for any help.
First argument in form cannot contain nil or be empty
This means that #read in your form is nil. Since you are in the show action of your Books controller, you have to define this variable in the books controller.
def show
#read = Read.new
...
end
I've read through many other topics here (1, 2, 3...) but none really solved my problem.
Here are my 3 models.
User
has_many :memberships
has_many :accounts, :through => :memberships
accepts_nested_attributes_for :memberships
end
Account
has_many :memberships
has_many :users, :through => :memberships
accepts_nested_attributes_for :memberships
end
Membership
attr_accessible :account_id, :url, :user_id
belongs_to :account
belongs_to :user
end
As you can see, my join model Membership has an additional attribute: :url.
In my Accounts table, I store names of online services, such as GitHub, Stack Overflow, Twitter, Facebook, LinkedIn.. I have 9 in total. It's a fixed amount of accounts that I don't tend to update very often.
In my User form, I'd like to create this:
The value entered in any of these field should be submitted in the Memberships table only, using 3 values:
url (the value entered in the text field)
user_id (the id of the current user form)
account_id (the id of the related account, e.g. LinkedIn is '5')
I have tried 3 options. They all work but only partially.
Option #1
<% for account in #accounts %>
<%= f.fields_for :memberships do |m| %>
<div class="field">
<%= m.label account.name %><br>
<%= m.text_field :url %>
</div>
<% end %>
<% end %>
I want to have 9 text field, one for each account. So I loop through my accounts, and create a url field related to my memberships model.
It shows my fields correctly on the first time, but the next time it'll display 81 fields:
Option #2
<% #accounts.each do |account| %>
<p>
<%= label_tag(account.name) %><br>
<%= text_field_tag("user[memberships_attributes][][url]") %>
<%= hidden_field_tag("user[memberships_attributes][][account_id]", account.id) %>
<%= hidden_field_tag("user[memberships_attributes][][user_id]", #user.id) %>
</p>
<% end %>
I'm trying to manually enter the 3 values in each column of my Memberships tables.
It works but :
displaying both account and user id's doesn't seem very secure (no?)
it will reset the fields everytime I edit my user
it will duplicate the values on each submit
Option #3 (best one yet)
<%= f.fields_for :memberships do |m| %>
<div class="field">
<%= m.label m.object.account.name %><br>
<%= m.text_field :url %>
</div>
<% end %>
I'm creating a nested form in my User form, for my Membership model.
It works almost perfectly:
exactly 9 fields, one for each account
no duplicates
But, it only works if my Memberships table is already populated! (Using Option #2 for example).
So I tried building some instances using the UsersController:
if (#user.memberships.empty?)
#user.memberships.build
end
But I still get this error for my m.label m.object.account.name line.
undefined method `name' for nil:NilClass
Anyway, I'm probably missing something here about has_many through models. I've managed to create has_and_belongs_to_many associations but here, I want to work on that join model (Membership), through the first model (User), using information about the third model (Account).
I'd appreciate your help. Thank you.
in the controller, fetch the list of memberships for a particular user
# controller
# no need to make this an instance variable since you're using fields_for in the view
# and we're building additional memberships later
memberships = #user.memberships
then loop through each account and build a membership if the user has no membership for an account yet.
# still in the controller
Account.find_each do |account|
unless memberships.detect { |m| m.account_id == account.id }
#user.memberships.build account_id: account.id
end
end
then in your view, you change nothing :)
I would use the following data-design approach. All users in your system should have the
memebership entries for all possible accounts. The active configurations will have a value for the url field.
User
has_many :memberships
has_many :accounts, :through => :memberships
has_many :active_accounts, :through => :memberships,
:source => :account, :conditions => "memberships.url IS NOT NULL"
accepts_nested_attributes_for :memberships
end
Now
curent_user.active_accounts # will return the accounts with configuration
curent_user.accounts # will return all possible accounts
Add a before_filter to initialize all the memberships that a user can have.
class UsersController
before_filter :initialize_memberships, :only => [:new, :edit]
private
def initialize_memberships
accounts = if #user.accounts.present?
Account.where("id NOT IN (?)", #user.account_ids)
else
Account.scoped
end
accounts.each do |account|
#user.memberships.build(:account_id => account.id)
end
end
end
In this scenario you need to initialize the memeberships before the new action and all the memberships should
be saved in the create action ( even the ones without url).
Your edit action doesn't need to perform any additional data massaging.
Note:
I am suggesting this approach as it makes the management of the form/data straight forward. It should only
be used if the number of Account's being associated is handful.
Ok, am still a newbie in ruby on rails trying to learn my way around. I have two models (User model and Comment model). Basically a user has a simple profile with an 'about me' section and a photo's section on the same page. Users must be signed in to comment on other users profiles.
My User Model
class User < ActiveRecord::Base
attr_accessible :email, :name, :username, :gender, :password, :password_confirmation
has_secure_password
has_many :comments
.
.
end
My Comment Model
class Comment < ActiveRecord::Base
belongs_to :user
attr_accessible :content
.
.
end
In my comments table, I have a user_id column that stores the id of the user whose profile has been commented on and a commenter_id column that stores the id of the user commenting on the profile.
Comment Form
<%= form_for([#user, #user.comments.build]) do |f| %>
<%= f.text_area :content, cols: "45", rows: "3", class: "btn-block comment-box" %>
<%= f.submit "Comment", class: "btn" %>
<% end %>
My comments Controller
class CommentsController < ApplicationController
def create
#user = User.find(params[:user_id])
#comment = #user.comments.build(params[:comment])
#comment.commenter_id = current_user.id
if #comment.save
.........
else
.........
end
end
end
This works fine storing both user_id and commenter_id in the database. My problem comes when displaying the user comments on the show page. I want to get the name of the user who commented on a specific profile.
In my user controller
def show
#user = User.find(params[:id])
#comments = #user.comments
end
I want to get the name of the user from the commenter_id but it keeps throwing errors undefined method 'commenter' for #<Comment:0x007f32b8c37430> when I try something like comment.commenter.name. However, comment.user.name works fine but it doesn't return what I want. Am guessing am not getting the associations right.
I need help getting the correct associations in the models so as to get the name from the commenter_id.
My last question, how do I catch errors in the comments form? Its not the usual form_for(#user) where you do like #user.errors.any?.
routes.rb
resources :users do
resources :comments, only: [:create, :destroy]
end
Try something like this in your models
class User < ActiveRecord::Base
has_many :received_comments, :class_name => "Comment", :foreign_key => "user_id"
has_many :given_comments, :class_name => "Comment", :foreign_key => "commenter_id"
end
class Comment < ActiveRecord::Base
belongs_to :user # comment about profile
belongs_to :commenter, :class_name => "User", :foreign_key => "commenter_id"
end
check out: http://guides.rubyonrails.org/association_basics.html
you can probably come up with better naming on the has_many collections, received and given were the best I could do on short notice :)
Note: foreign_key is option in many cases, left it in above - i think it helps with clarity
has_many fk refers to the the column in the many table (other table)
belongs_to fk refers to the column in the many table (this table)