For example, I have a model, it has 'id_number(integer)' and 'date(string)', I have:
<%= f.label :date %>
<%= f.text_field :date %>
<%= f.submit %>
I want to get this date(string) and save it as 'id_number' in integer to the model. How can I achieve this by ruby on rails?
You could use a before_save callback to handle this.
class YourModelClass < ActiveRecord::Base
before_save :date_to_id_number
def date_to_id_number
#code that converts date to id_number
end
end
Related
Since more than a month I try to get behind the secrets of form objects in Rails 4.
Using virtus, I am already able to build very simple forms. However, I fail to develop a form object that replaces accepts_nested_attributes_for (in the model) and fields_for (in the form view).
In this question I explain a small phonebook-example: the form provides the possibility to enter a person's name and 3 phone numbers at once (find the whole code here).
Now I try to do the same with a form object. I get as far as this:
# forms/person_form_new.rb
class PersonFormNew
class PhoneFormNew
include Virtus
include ActiveModel::Model
attr_reader :phone
attribute :phone_number, String
end
include Virtus
include ActiveModel::Model
attr_reader :person
attribute :person_name, String
attribute :phone, PhoneFormNew
def persisted?
false
end
def save
if valid?
persist
true
else
false
end
end
private
def persist
#person = Person.create(name: person_name)
#person.phones.build(:phone)
end
end
# views/people/new.html.erb
<h1>New Person</h1>
<%= form_for #person_form, url: people_path do |f| %>
<p>
<%= f.label :person_name %> </ br>
<%= f.text_field :person_name %>
</p>
<p>
<%= f.fields_for :phone do |f_pho| %>
<%= f_pho.label :phone_number %> </ br>
<%= f_pho.text_field :phone_number %>
<% end %>
<p>
<%= f.submit %>
</p>
<% end %>
This gives me the error
undefined method `stringify_keys' for :phone:Symbol
line: #person.phones.build(:phone)
I fear however, this is not the only error.
Can you point me the way to realize a one-to-many assignment with a form object (preferable using Virtus)?
One solution is to create the associated object in a separate function on the form model. I was succussful by doing the following:
def persist!
#user.save!
#account.save!
create_admin_membership
end
def create_admin_membership
#membership = Membership.create! do |membership|
membership.user = #user
membership.account = #account
membership.admin = true
end
end
You can find an extended explanation here: http://w3facility.org/question/how-to-create-another-object-when-creating-a-devise-user-from-their-registration-form-in-rails/
I have a Bill object, which has many Due objects. The Due object also belongs to a Person. I want a form that can create the Bill and its children Dues all in one page. I am trying to create a form using nested attributes, similar to ones in this Railscast.
Relevant code is listed below:
due.rb
class Due < ActiveRecord::Base
belongs_to :person
belongs_to :bill
end
bill.rb
class Bill < ActiveRecord::Base
has_many :dues, :dependent => :destroy
accepts_nested_attributes_for :dues, :allow_destroy => true
end
bills_controller.rb
# GET /bills/new
def new
#bill = Bill.new
3.times { #bill.dues.build }
end
bills/_form.html.erb
<%= form_for(#bill) do |f| %>
<div class="field">
<%= f.label :company %><br />
<%= f.text_field :company %>
</div>
<div class="field">
<%= f.label :month %><br />
<%= f.text_field :month %>
</div>
<div class="field">
<%= f.label :year %><br />
<%= f.number_field :year %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<%= f.fields_for :dues do |builder| %>
<%= render 'due_fields', :f => builder %>
<% end %>
<% end %>
bills/_due_fields.html.erb
<div>
<%= f.label :amount, "Amount" %>
<%= f.text_field :amount %>
<br>
<%= f.label :person_id, "Renter" %>
<%= f.text_field :person_id %>
</div>
UPDATE to bills_controller.rb
This works!
def bill_params
params
.require(:bill)
.permit(:company, :month, :year, dues_attributes: [:amount, :person_id])
end
The proper fields are rendered on the page (albeit without a dropdown for Person yet) and submit is successful. However, none of the children dues are saved to the database, and an error is thrown in the server log:
Unpermitted parameters: dues_attributes
Just before the error, the log displays this:
Started POST "/bills" for 127.0.0.1 at 2013-04-10 00:16:37 -0700
Processing by BillsController#create as HTML<br>
Parameters: {"utf8"=>"✓",
"authenticity_token"=>"ipxBOLOjx68fwvfmsMG3FecV/q/hPqUHsluBCPN2BeU=",
"bill"=>{"company"=>"Comcast", "month"=>"April ",
"year"=>"2013", "dues_attributes"=>{
"0"=>{"amount"=>"30", "person_id"=>"1"},
"1"=>{"amount"=>"30", "person_id"=>"2"},
"2"=>{"amount"=>"30", "person_id"=>"3"}}}, "commit"=>"Create Bill"}
Has there been some change in Rails 4?
Seems there is a change in handling of attribute protection and now you must whitelist params in the controller (instead of attr_accessible in the model) because the former optional gem strong_parameters became part of the Rails Core.
This should look something like this:
class PeopleController < ActionController::Base
def create
Person.create(person_params)
end
private
def person_params
params.require(:person).permit(:name, :age)
end
end
So params.require(:model).permit(:fields) would be used
and for nested attributes something like
params.require(:person).permit(:name, :age, pets_attributes: [:id, :name, :category])
Some more details can be found in the Ruby edge API docs and strong_parameters on github or here
From the docs
To whitelist an entire hash of parameters, the permit! method can be used
params.require(:log_entry).permit!
Nested attributes are in the form of a hash. In my app, I have a Question.rb model accept nested attributes for an Answer.rb model (where the user creates answer choices for a question he creates). In the questions_controller, I do this
def question_params
params.require(:question).permit!
end
Everything in the question hash is permitted, including the nested answer attributes. This also works if the nested attributes are in the form of an array.
Having said that, I wonder if there's a security concern with this approach because it basically permits anything that's inside the hash without specifying exactly what it is, which seems contrary to the purpose of strong parameters.
or you can simply use
def question_params
params.require(:question).permit(team_ids: [])
end
Actually there is a way to just white-list all nested parameters.
params.require(:widget).permit(:name, :description).tap do |whitelisted|
whitelisted[:position] = params[:widget][:position]
whitelisted[:properties] = params[:widget][:properties]
end
This method has advantage over other solutions. It allows to permit deep-nested parameters.
While other solutions like:
params.require(:person).permit(:name, :age, pets_attributes: [:id, :name, :category])
Don't.
Source:
https://github.com/rails/rails/issues/9454#issuecomment-14167664
Today I came across this same issue, whilst working on rails 4, I was able to get it working by structuring my fields_for as:
<%= f.select :tag_ids, Tag.all.collect {|t| [t.name, t.id]}, {}, :multiple => true %>
Then in my controller I have my strong params as:
private
def post_params
params.require(:post).permit(:id, :title, :content, :publish, tag_ids: [])
end
All works!
If you use a JSONB field, you must convert it to JSON with .to_json (ROR)
I have three models:
class Rate < ActiveRecord::Base
attr_accessible :user_id, :car_id, :rate
belongs_to :user
belongs_to :car
end
class User < ActiveRecord::Base
attr_accessible :name
has_many :rates
accepts_nested_attributes_for :rates
end
class Car < ActiveRecord::Base
attr_accessible :name
has_many :rates
accepts_nested_attributes_for :rates
end
And one controller:
class UsersController < ResourceController
def new
# Assume user is loaded
#user.rates.build
end
end
I'm trying to build a nested form that will associate a list of users/cars and their associated rates.
Something like:
<% form_for #user do |f| %>
<%= #user.name %><br />
<% Car.all.each do |car| %>
<%= car.name %><br />
<%= f.fields_for :rates do |r| %>
<%= r.number_field :rate %>
<% end %>
<% end %>
<% end %>
The problem is that I would like the Rate model to store data as follows:
USER_ID CAR_ID RATE
1 1 10
1 2 20
1 3 30
2 1 40
3 2 50
I cannot figure out how to properly build the fields_for helper to build the proper params for both the user_id and the car_id.
Something like:
user[car=1][rate]
user[car=2][rate]
I've tried being more explicit with the fields_for like this:
<%= r.fields_for 'user[car][rate]' %>
But it still doesn't build out the nested parameters properly. The car parameter is not correctly identified.
Any help would be appreciated! Thanks.
EDIT:
The controller action has to be under user. The example above has been shortened for brevity but other user-related attributes are available through the form so it has to use the users controller.
ANSWER:
I figured out a way to do it. I've added my own answer that explains it.
<% form_for #user do |f| %>
<%= #user.name %><br />
<%= f.fields_for :rates do |r| %>
<% Car.all.each do |car| %>
<%= car.name %><br />
<%= r.number_field :rate %>
<% end %>
<% end %>
<% end %>
This may be solution of your problem. Just check it.
The form is going to create a new rate instead of a new user, so the method should be in RatesController instead of UsersController.
With this logic the problem seems solved. You can write field_for rate[user] and field_for rate[car]
I think I've got it figured out.
In my controller, I've modified the build method as follows:
Car.all.each { |c| #user.rates.build(car_id: c.id) } if #user.rates.count == 0
Then, in my model, I need the following:
attr_accessible :rates_attributes
Finally, the fields_for block should look like this (remember, this is in the #user form object f):
<%= f.fields_for :rates do |r| %>
<%= r.hidden_field :car_id %>
<%= r.object.car.name %><br />
<%= r.number_field :rate %>
<% end %>
This builds the params hash properly and create the rate model entries when the form is submitted.
The check on existing user rates in the controller will ensure that the existing values are used in the form and new ones are not built (which I thought build took into consideration... ?).
I have ActiveRecord with a subclass and its associated with another ActiveRecord object.
I am able to create my object with nested attributes with a form with nested attributes no problem for a new object (following Ryan Bates rails cast - Thanks by the way :)). However when i do an update it fails to save the changes to either the main object or the related object when submitted
I have the following Activerecord classes and sub class.
class Room < ActiveRecord::Base
attr_accessible :name, :type, room_headers_attributes
has_many :room_headers, dependent: :destroy
accepts_nested_attributes_for :room_headers , :allow_destroy => true
end
And the sub class is
class BigRoom < Room
end
And the related class is
class RoomHeader < ActiveRecord::Base
attr_accessible :key, :room_id, :value
belongs_to :room
end
In my room controller I created the nested objects. note that i'm using :type to specify the subclass type
def new
#room = current_user.passes.build(params[:room])
#room.type = params[:type]
3.times do
room_header = #room.room_headers.build
end
....
end
....
def edit
#room = Room.find(params[:id])
end
def update
#room = Room.find(params[:id])
if #room.update_attributes(params[:room])
...
The form used for creating and editing is the same
<%= form_for(#room) do |f| %>
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<%= f.fields_for :room_headers do |builder| %>
<%= render 'room_header_fields', f: builder %>
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end &>
And the _room_headers.html.erb partial is
<p class="fields">
<%= f.label :key, "Key" %>
<%= f.text_field :key %>
<%= f.label :value, "Value" %>
<%= f.text_field :value %>
<%= f.check_box :_destroy %>
<%= f.label :_destroy, "Remove Header" %>
</p>
To recap on the problem. I can successfully create a new BigRoom. In the new form when i create the BigRoom and I can successfully set values for the RoomHeader class and these are all saved successfully.
However when i Edit the the record and submit changes for update, nothing is saved. Either for changes for the Bigroom attributes or to the associated RoomHeader records.
first try by
if #room.update_attribute(params[:room])
rather
if #room.update_attributes(params[:room])
if this works then their are some errors with your validdations
Ok, nested attributes were a red herring. The problem is with STI
The Rails form helper guide says you can’t rely on record identification with STI.
In the form_for we need to coearce the ids to be the base type id otherwise the edit fails
so
<%= form_for(#room) do |f| %>
should be
<%= form_for(#room.becomes(Room) do |f| %>
if you look at the difference in the html output
the problem html would create ids like big_room_fieldname when in edit mode
when using .becomes we get ids like room_fieldname. in whihc case it saves and updates ok
If I have the models with the following associations:
class Business
has_many :products
class Product
belongs_to :business
And I generate 3 products in the controller:
def new
#business = Business.new
3.times do
#business.products.build
end
end
Making my form look like this:
<%= form_for #business do |f| %>
<% f.text_field :business_name %>
<%= f.fields_for :products do |pf| %> # x2 more products generated
<% pf.text_field :name %>
<% pf.text_field :price %>
<% pf.text_field :date %>
<% end %>
If I want one of the fields to act as a global field for the rest of the products how could I take a field like the :price and put it outside of the f.fields_for :products to have it be the :price for all of the products?
Thank you.
If you need to initialize the price, do it in the controller. But if you need a field that doesn't map to a model directly, use the regular form helpers:
<%= text_field_tag 'global_price' %>
and then in the controller on the create action, it is available as
params[:global_price]
Alternately, you could define a method in your Business model:
def global_price=
#do something with the global price, such as updating child object...
# I'm not sure if the child form objects have been instantiated yet though
end
and then you can use it in your business form:
<%= f.text_field :global_price %>
If you need to update the child objects, you might have to do that at a later time; instead of that method, make it
attr_accessor :global_price
Which makes it an instance variable. Then you can use a before_save filter to update the child objects.
before_save :update_global_price
def update_global_price
#do something with #global_price
end