I am trying to understand how to make a nested form of my models but I am struggeling with understanding how and what I need to do it. I have been reading the Rails documentation and looked at the railscast but they just mention the accepts_nested_attributes_for method etc without explaining. Can someone please help?
Per API of Rails it's said:
Nested attributes allow you to save attributes on associated records through the parent...
Example: it shows how we can manage posts through Member, fields_for is used to manage associated fields in a form, passing it the name of the associated model and then loop through all of the associated post records and create a form builder for each of them.
#controller
def new
#member = Member.new
end
#model
class Post < ActiveRecord::Base
belongs_to :member
end
class Member < ActiveRecord::Base
has_many :posts
accepts_nested_attributes_for :posts
end
#form
<%= form_for #member do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :name %><br />
<%= f.text_field :name %>
</p>
<%= f.fields_for :posts do |builder| %>
<p>
<%= builder.label :account %><br />
<%= builder.text_area :account %>
</p>
<% end %>
<p><%= f.submit "Submit" %></p>
<% end %>
Rails API: http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html
Related
I'm trying to include nested_form in one of my model new form.
<%= form_for :master_box, url: master_boxes_path do |f| %>
<%= f.label :number %><br>
<%= f.text_field :number %>
<%= f.fields_for :orders do |o| %>
<fieldset>
<%= o.label :number, "Number" %>
<%= o.text_field :number %>
</fieldset>
<% end %>
<br>
<%= f.submit %>
<% end %>
I don't know why when I submit to create my masterbox, my params don't contain orders_attributes.
Here's my models :
class MasterBox < ActiveRecord::Base
has_many :orders
accepts_nested_attributes_for :orders
end
class Order < ActiveRecord::Base
has_many :products
belongs_to :master_box
end
and my strong parameters :
def master_box_params
params.require(:master_box).permit(:number, :number_orders, orders_attributes: [:number])
end
It is pretty simple but I don't understand why I don't have orders_attributes in my params.
I have this instead, only "orders" :
Try changing the first line of your form to:
<%= form_for #master_box, url: master_boxes_path do |f| %>
and also passing through the id in your params:
def master_box_params
params.require(:master_box).permit(:number, :number_orders, orders_attributes: [:id, :number])
end
fields_for :orders creates the orders parameter that you are seeing. This bit of your strong parameters orders_attributes: [:number] is allowing the numbers attribute of orders to be passed through. You should be looking at the orders parameter that you are receiving. That's where the data you want is.
I'm working a very simple forum software to help get my feet wet with ruby on rails. What I am trying to do is add a text area for the post content when a user creates a new topic, but every time I try to add it in the topic form, I get the following error:
NoMethodError in Topics#new
Showing /Users/Ken/dev/forums/app/views/topics/_form.html.erb where line #11 raised:
undefined method `merge' for :content:Symbol
Here's my new topic form:
<%= form_for #topic do |f| %>
<%= f.error_messages %>
<% if params[:forum] %>
<%= f.hidden_field :forum_id, :value => params[:forum] %>
<% end %>
<p>
<%= f.label :name %><br />
<%= f.text_field :name %>
</p>
<p>
<%= f.text_area :post, :content %>
</p>
<p><%= f.submit "Create" %></p>
<% end %>
Here's my Topic model:
class Topic < ActiveRecord::Base
attr_accessible :name, :last_poster_id, :last_post_at
belongs_to :forum
has_many :posts, :dependent => :destroy
end
Here's my Post model:
class Post < ActiveRecord::Base
attr_accessible :content
belongs_to :topic
end
How can I get the text area working correctly in the topic form? Do I need to add it to the topic model in order to access it, and if so, how can I do that?
You can use the fields_for helper. See this link, http://apidock.com/rails/ActionView/Helpers/FormHelper/fields_for. The first argument could be a Post.new and then you can have the topic text field inside of that block. The end result is a nested form which you can parse in the controller.
I am using Rails 3.1 and am working on a discussion forum. I have a model called Topic, each of which has many Posts. When the user makes a new topic, they should also make the first Post as well. However, I am not sure how I can do this in the same form. Here is my code:
<%= form_for #topic do |f| %>
<p>
<%= f.label :title, "Title" %><br />
<%= f.text_field :title %>
</p>
<%= f.fields_for :post do |ff| %>
<p>
<%= ff.label :body, "Body" %><br />
<%= ff.text_area :body %>
</p>
<% end %>
<p>
<%= f.submit "Create Topic" %>
</p>
<% end %>
class Topic < ActiveRecord::Base
has_many :posts, :dependent => :destroy
accepts_nested_attributes_for :posts
validates_presence_of :title
end
class Post < ActiveRecord::Base
belongs_to :topic
validates_presence_of :body
end
... but this doesn't seem to be working. Any ideas?
Thanks!
#Pablo's answer seems to have everything you need. But to be more specific...
First change this line in your view from
<%= f.fields_for :post do |ff| %>
to this
<%= f.fields_for :posts do |ff| %> # :posts instead of :post
Then in your Topic controller add this
def new
#topic = Topic.new
#topic.posts.build
end
That should get you going.
A very good explanation from Ryan Bates here and here
For your particular case: you are using a model (:post), instead of an association (:posts) when you call fields_for.
Also check for the proper use of <%= ... %>. In rails 3.x the bahaviour of the construct changed. Block helpers (form_for, fields_for, etc) dont need it, and inline helpers (text_field, text_area, etc) do need it.
Is there a preferred way to create a hierarchy of new ActiveRecord model objects with associations (e.g. creating a model that has_many children) within a single action? Is this just something that should be done in separate bits?
Take the example of a blog post model which has_many comments. I add support for the author of the blog post adding an initial comment within the same form for the blog post. Right now, what I do is have an after_create call in the blog post that checks to see if there is a comment, and the blog post creates a comment if it exists.
I was thinking of just building (.build) the comment with an unsaved blog post, but apparently that does not work since the blog post does not actually have an id yet since it has not yet been saved. I'm interested in finding out what approaches other people have taken.
My preference is for nested model forms.
Models:
class Comment < ActiveRecord::Base
belongs_to :post
end
class Post < ActiveRecord::Base
has_many :comments, :dependent => :destroy
accepts_nested_attributes_for :comments
end
Controller:
#post = post.new
#post.comments.build
View:
<% form_for #post do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :title %><br />
<%= f.text_field :title %>
</p>
<% f.fields_for :comments do |builder| %>
<p>
<%= builder.label :content, "Comment" %><br />
<%= builder.text_area :content, :rows => 5 %>
</p>
<% end %>
<p><%= f.submit "Submit" %></p>
<% end %>
I have a model that has an arbitrary number of children entities. For simplicity lets call the entities Orders and Items. I would like to have a create Orders form where I input the order information, as well as add as many items as I want. If I click the "Add another item" button, a new set of form elements will be added to input the new data, amounts, etc..
I could hack this out in pure javascript, but I'm pretty sure there has to be a more magical, railsish way to do it, maybe with a partial view or something. I'm just a little too new to rails to know what it is.
What is the best way to dynamically add the new form elements, and then to access them in the create controller?
Can't beat this Railscasts.com tutorial provided by Ryan Bates.
Episode 196: Nested Model Form, pt. 1
Here's an example that works with just a single level of nesting
Models
models/company.rb
class Company < ActiveRecord::Base
has_many :people, :dependent => :destroy
accepts_nested_attributes_for :people, :allow_destroy => true
end
models/person.rb
class person < ActiveRecord::Base
belongs_to :company
end
Controllers
companies_controller.rb
def new
#company = Company.new
3.times { person = #company.people.build }
end
Views
views/companies/_form.html.erb
<% form_for #company do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :name %><br />
<%= f.text_field :name %>
</p>
<%= f.fields_for :people do |builder| %>
<%= render "people_fields", :f => builder %>
<% end %>
<p><%= f.submit "Submit" %></p>
<% end %>
views/companies/_people_fields.html.erb
<p>
<%= f.label :name, "Person" %>
<%= f.text_field :name %>
<%= f.check_box :_destroy %>
<%= f.label :_destroy, "Remove" %>
</p>