i need your help to create parent-child relation.
i have a problem to make the create of the child working fine.
this is the model:
class Nccheklist < ActiveRecord::Base
has_many :children, class_name: "Nccheklist", foreign_key: "parent_id"
belongs_to :parent, class_name: "Nccheklist"
def has_parent?
parent.present?
end
def has_children?
children.exists?
end
end
the controller:
def create
#nccheklist = Nccheklist.new(nccheklist_params)
if #nccheklist.save
redirect_to nccheklists_url, notice: 'Nccheklist was successfully created.'
else
render :new
end
end
and the view :
<%= form_for(#nccheklist) do |f| %>
<% if #nccheklist.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#nccheklist.errors.count, "error") %> prohibited this nccheklist from being saved:</h2>
<ul>
<% #nccheklist.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :name %><br>
<%= f.text_field :name %>
</div>
<div>
<%= f.collection_select(:parent_id, #rootcat, :id, :name) %>
</div>
<br/><br/>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
when i submit the form, parent_id always equal null on database !
can someone help me please.
thanks.
add the following to the class definition
accepts_nested_attributes_for :children, allow_destroy: true
Related
My models
class Game < ApplicationRecord
has_many :rounds
accepts_nested_attributes_for :rounds
end
class Round < ApplicationRecord
belongs_to :game
end
controller
def new
#game = Game.new
3.times { #game.rounds.build }
end
view
<%= form_with scope: :game, url: games_path, local: true do |form| %>
<p>
<%= form.label :title %><br>
<%= form.text_field :title %>
</p>
<p>
<%= form.label :game_date %><br>
<%= form.date_field :game_date %>
</p>
<ul>
<%= form.fields_for :rounds do |builder| %>
<li>
<%= builder.label :title %>
<%= builder.text_field :title %>
<%= builder.label :order %>
<%= builder.text_field :order %>
</li>
<% end %>
</ul>
<p>
<%= form.submit %>
</p>
<% end %>
The above code only generates one "round" of record when new is building 3 records.
I am on rails 5.2.1
It is because you have a different object (formbuilder) when using form.
<%= form_with model: #game, local: true do |form| %>
Or
<%= form_with scope: #game, url: games_path, local: true do |form| %>
instead of
<%= form_with scope: :game, url: games_path, local: true do |form| %>
which produces the desire result. Have a look at this blog for better understanding.
It turns out you have to use form_for instead of the new form_with.
I am working on building a blog with categorization. I am a bit stuck on how to implement categorization in the form. I have setup a has many through relationship and want to add check boxes to associate a blog with multiple categories. What I have so far is passing the categories through to the view, and I can list them out, however I cannot get the form_for method working for some reason.
Here is my code.
blog model
class Blog < ActiveRecord::Base
attr_accessible :body, :title, :image
has_many :categorizations
has_many :categories, through: :categorizations
has_attached_file :image, :styles => { :medium => "300x300>", :thumb => "100x100>" }
validates :title, :body, :presence => true
end
Category Model
class Category < ActiveRecord::Base
has_many :categorizations
has_many :blogs, through: :categorizations
attr_accessible :name
end
Categorization Model
class Categorization < ActiveRecord::Base
attr_accessible :blog_id, :category_id
belongs_to :blog
belongs_to :category
end
Blog new controller
def new
#blog = Blog.new
#categories = Category.all
respond_to do |format|
format.html # new.html.erb
format.json { render json: #blog }
end
end
Blog new form view
<%= form_for(#blog, :url => blogs_path, :html => { :multipart => true }) do |f| %>
<% if #blog.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#blog.errors.count, "error") %> prohibited this blog from being saved:</h2>
<ul>
<% #blog.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :title %><br />
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.file_field :image %>
</div>
<div class="field">
<%= f.label :body %><br />
<%= f.text_area :body %>
</div>
<div class="field">
Categories:
<% #categories.each do |category| %>
<% fields_for "blog[cat_attributes][]", category do |cat_form| %>
<p>
<%= cat_form.check_box :name %>
</p>
<% end %>
<% end %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
This code is my failing point
<% #categories.each do |category| %>
<% fields_for "blog[cat_attributes][]", category do |cat_form| %>
<p>
<%= cat_form.check_box :name %>
</p>
<% end %>
<% end %>
Although I am not positive I am approaching any of it right since I am currently learning. Any advice on how to accomplish this.
Thanks,
CG
First of all, you probably don't need a separate Categorization model unless there's a use case you haven't described here. You can set up a many-to-many relationship like this:
class Blog < ActiveRecord::Base
has_and_belongs_to_many :categories
end
class Category < ActiveRecord::Base
has_and_belongs_to_many :blogs
end
You should have a database table like this:
class CreateBlogsCategories < ActiveRecord::Migration
def change
create_table :blogs_categories, id: false do |t|
t.references :blog
t.references :category
end
end
end
Then you can construct the view like this:
<div class="field">
Categories:
<% #categories.each do |category| %>
<%= label_tag do %>
<%= check_box_tag 'blog[category_ids][]', category.id, #blog.category_ids.include?(category.id) %>
<%= category.name %>
<% end %>
<% end %>
</div>
Lastly, in your form_for, you specify url: blogs_path - you should remove this if you plan to use this form for the edit action as well, because that should generate a PUT request to /blogs/:id. Assuming you used resources :blogs in routes.rb, Rails will determine the correct path for you based on the action used to render the form.
I recently followed a tutorial about nested forms by Ryan Bates and did basically the same thing as he did just with other names. I wanted to nest assignments in the order form and I would like to build an assignment for every bun to that order and the user should put a count in the form.
So my controller looks like this
def new
#order = Order.new
#buns = Bun.all
#buns.each do |bun|
#order.assignments.build(:bun_id => bun.id)
end
end
And the _form partial looks like this
<%= form_for(#order) do |f| %>
<div class="field">
<%= f.label :user_id %><br />
<%= f.number_field :user_id %>
</div>
<div id="assignments" class="field">
<% f.fields_for :assignments do |builder| %>
<div id="assignment" class="field">
<%= builder.label :count, "Anzahl" %>
<%= builder.text_field :count %>
<%= builder.object.bun_id %>
<% end %>
</div>
</div>
<div class="field">
<%= f.label :due_to %><br />
<%= f.datetime_select :due_to %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
The Order model has this part
has_many :assignments
has_one :user
accepts_nested_attributes_for :assignments
And the Assignments model this one:
attr_accessible :bun_id, :order_id, :count
belongs_to :bun
belongs_to :order
As i log the assignments out there are all, which should be build, so why weren't the fields rendered?
Thanks for your help!
You are missing an equal sign (=) in your erb :
<%= f.fields_for :assignments do |builder| %>
I am trying to flash messages in a form when they do not meet the validation requirements but can't work out how to achieve this.
I have the following setup:
models/item.rb
class Item < ActiveRecord::Base
attr_accessible :condition, :day, :description, :subtitle, :title
validates :user_id, presence: true
validates :title, presence: true
validates :description, presence: true, length: { minimum: 20 }
belongs_to :user
end
controllers/items_controller.rb
class ItemsController < ApplicationController
before_filter :authenticate_user!
def new
#item = Item.new
end
def show
#item = Item.find(params[:id])
end
def create
#item = current_user.items.build(params[:item])
if #item.save
flash[:success] = "Your item has been saved"
redirect_to root_path
else
render 'new'
end
end
def destroy
#item.destroy
redirect_back_or root_path
end
end
and finally views/items/new.html.erb
<h1>Items Base</h1>
<div class="row">
<div class="span6 offset3">
<%= form_for(#item) do |f| %>
<%= f.label :title, "Title" %>
<%= f.text_field :title %>
<%= f.label :subtitle, "Subtitle" %>
<%= f.text_field :subtitle %>
<%= f.label :condition, "Condition" %>
<%= f.number_field :condition %>
<%= f.label :description, "Description" %>
<%= f.text_field :description %>
<%= f.label :day, "Day" %>
<%= f.text_field :day %>
<%= f.submit "List", class: "btn btn-large btn-primary" %>
<% end %>
</div>
</div>
Essentially I would like to be able to flash the message "Description too short!" when the user leaves it blank or below 20 characters, or flash the message "Title required" if it is left blank. Any thoughts on how best to achieve this. Also if anyone has any good resources on working with the flash it would be much appreciated. Thanks.
Here is how I do it:
Here is the form:
<%= form_for(#client) do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<%= f.label :company_name %>
<%= f.text_field :company_name %>
<%= f.submit "Save changes", class: "btn btn-large btn-primary" %>
<% end %>
And here is my error_messages partial:
<% if object.errors.any? %>
<div id="error_explanation">
<div class="alert alert-error">
The form contains <%= pluralize(object.errors.count, "error") %>.
</div>
<ul>
<% object.errors.full_messages.each do |msg| %>
<li>* <%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
I'm using nested_attributes and trying to implement the add/remove fields on-the-fly throu ajax following Ryan Bates screencast about Nested Model (#196)
Doing this, it won't work, but when removing the "link_to_add_fields" line, it works fine.
The problem is that I'm don't know if I doing this all associations right.
<%= form_for(#item) do |f| %>
<% if #item.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#item.errors.count, "error") %> prohibited this item from being saved:</h2>
<ul>
<% #item.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :title %><br />
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.label :item_type_id %><br />
<%= f.select :item_type_id, #item_types.collect { |p| [ p.title, p.id ]} %>
<br />
<%= f.fields_for :item_parts do |parts_form| %>
<%= render "item_part_fields", :p => parts_form %>
<% end %>
</div>
<%= link_to_add_fields "Add Part", f, :part %>
<div class="actions">
<%= button_for "Save Item", :class => 'positive pill button', :button_type => 'submit' %>
</div>
<% end %>
Actually my models are:
"ItemPart" model:
class ItemPart < ActiveRecord::Base
belongs_to :item
belongs_to :part
end
"Item" model:
class Item < ActiveRecord::Base
belongs_to :item_type
has_many :item_parts
has_many :parts, :through => :item_parts
accepts_nested_attributes_for :item_parts, :allow_destroy => true
after_save :save_id
validates :title, :presence => true
def save_id
item_part_attributes = [ { :item_id => self.id } ]
end
end
"Part" model:
class Part < ActiveRecord::Base
has_one :part_type
has_many :item_parts
has_many :items, :through => :item_parts
end
The error I'm getting doing this way:
undefined method `klass' for nil:NilClass
Extracted source (around line #26):
23: <%= render "item_part_fields", :p => parts_form %>
24: <% end %>
25: </div>
26: <%= link_to_add_fields "Add Part", f, :item %>
27: <div class="actions">
Application trace
app/helpers/application_helper.rb:44:in `link_to_add_fields'
app/views/items/_form.html.erb:26:in `block in _app_views_items__form_html_erb__1418129287024756954_2169222480__3228169100620818569'
app/views/items/_form.html.erb:1:in `_app_views_items__form_html_erb__1418129287024756954_2169222480__3228169100620818569'
app/views/items/edit.html.erb:3:in `_app_views_items_edit_html_erb___1857878264245794505_2169270380_890290209246324491'
Application_helper.rb
def link_to_add_fields(name, f, association)
new_object = f.object.class.reflect_on_association(association).klass.new # error line :44
fields = f.fields_for(association, new_object, :child_index => "new_#{association}") do |builder|
render(association.to_s.singularize + "_fields", :f => builder)
end
link_to_function(name, "add_fields(this, '#{association}', '#{escape_javascript(fields)}')" )
end
After hours and hours doing tests and googling a lot, I get it finally solved.
Seems that I'd to use the same local variable name to render the partial used for the form_for and then use it again as a helper method parameter needed. (In this case, "f" variable.)
I pasting the cleaning working code below
<%= form_for(#item) do |f| %>
<p>
<%= f.label :title %><br />
<%= f.text_field :title %>
</p>
<p>
<%= f.label :item_type_id %><br />
<%= f.select :item_type_id, #item_types.collect { |p| [ p.title, p.id ]} %><br />
</p>
<p>
<%= f.fields_for :item_parts do |parts_form| %>
<%= render "item_part_fields", :f => parts_form %>
<% end %>
</p>
<p><%= link_to_add_fields "Add Part", f, :item_parts %></p>
<p><%= button_for "Save Item", :class => 'positive pill button', :button_type => 'submit' %></p>
<% end %>
Hope this going to help someone someday :)
There is a mistake in your add more button. This should be,
<p><%= link_to_add_fields "Add Part", f, :item_parts %></p>
The association name should be the table name on which have many relation is.