I am running into a strange situation, considering the following models:
class Collection < ActiveRecord::Base
attr_accessible :name, :season, :year
has_many :collection_items_assocs
has_many :items, :through => :collection_items_assocs
end
class Item < ActiveRecord::Base
attr_accessible :name, :reference, :item_type_id
has_many :pictures
has_one :item_type
end
class CollectionItemsAssoc < ActiveRecord::Base
attr_accessible :collection_id, :item_id
belongs_to :item
belongs_to :collection
end
I can successfully retrieve Items associated to a Collection with the following code:
# GET /collections/1
# GET /collections/1.json
def show
#collection = Collection.find(params[:id])
#collection.items = Collection.find(params[:id]).items
respond_to do |format|
format.json { render json: #collection.to_json(:include => {:items => #collection}) }
end
end
But when I try to include pagination (for items) like that
# GET /collections/1
# GET /collections/1.json
def show
#collection = Collection.find(params[:id])
**#collection.items = Collection.find(params[:id]).items.paginate(:page => params[:page],:per_page =>1)**
respond_to do |format|
format.json { render json: #collection.to_json(:include => {:items => #collection}) }
end
end
It works for the following call
/retailapp/collections/1?format=json&**page=1**
Then if I call
/retailapp/collections/1?format=json&**page=2**
the records in the association table CollectionItemsAssoc are deleted
I really don't get it
Thanks for your help
The problem is the code to fetch the items
#collection.items = Collection.find(params[:id]).items
it assigned the fetched items to current collection object.
you need to change the response to support the pagination on associate objects
def show
#collection = Collection.find(params[:id])
respond_to do |format|
format.json {
json_hash = #collection.as_json
json_hash[:items] = #collection.items.paginate(:page => params[:page],:per_page =>1).as_json
render json: json_hash.to_json
}
end
Additionally you can overwrite to_json method inside Collection model.
Related
i use rails 5 , simple form. in my app there is a Category model and there is a OnlineProduct model. i dont know why when i want to add some categories to my OnlineProduct association table remain empty and don't change.
Category model:
class Category < ApplicationRecord
has_ancestry
has_and_belongs_to_many :internet_products
end
InternetProduct model:
class InternetProduct < ApplicationRecord
belongs_to :user
belongs_to :business
has_and_belongs_to_many :categories
end
InternetProduct controller:
def new
#internet_product = InternetProduct.new
end
def create
#internet_product = InternetProduct.new(internet_product_params)
respond_to do |format|
if #internet_product.save
format.html { redirect_to #internet_product, notice: 'Internet product was successfully created.' }
format.json { render :show, status: :created, location: #internet_product }
else
format.html { render :new }
format.json { render json: #internet_product.errors, status: :unprocessable_entity }
end
end
end
private:
def internet_product_params
params.require(:internet_product).permit(:name, :description, :mainpic, :terms_of_use,
:real_price, :price_discount, :percent_discount,
:start_date, :expire_date, :couponـlimitation, :slung,
:title, :meta_data, :meta_keyword, :enability, :status,
:like, :free_delivery, :garanty, :waranty, :money_back,
:user_id, :business_id,
categoriesـattributes: [:id, :title])
end
and in the view only the part of who relate to categories :
<%= f.association :categories %>
all the categories list in view (form) but when i select some of them not save in database. in rails console i do this
p = InternetProduct.find(5)
p.categories = Category.find(1,2,3)
this save to database without any problem, what should i do ?
tanks for reading this
I found solution to solve this. when we use has_and_belong_to_many or any other relation , if you want to use collection select in simple_form , in the model also should be add this command for nesting form
accepts_nested_attributes_for :categories
also in the controller in related method for example in the new we should
def new
#internet_product = InternetProduct.new
#internet_product.categories.build
end
I have some troubles to make an association between 2 tables.
I have Users who can write Posts
Here is my migration file :
class LinkUsersAndPosts < ActiveRecord::Migration
def change
add_column :posts, :user_id, :integer
add_index :posts, :user_id
end
end
My models :
class Post < ActiveRecord::Base
attr_accessible :content, :title
belongs_to :user
end
class User < ActiveRecord::Base
attr_accessible :email, :login, :password, :password_confirmation, :rights
has_many :posts
end
My controller :
class PostsController < ApplicationController
respond_to :json
def index
#posts = Post.includes(:user).all
respond_with #posts
end
def create
#post = Post.new(params[:post])
#post.user = current_user
if #post.save
render json: #post, status: :created, location: #post
else
render json: #post.errors, status: :unprocessable_entity
end
end
end
The posts is correctly created, the user_id is set all is fine.
The problem is when i want to retrieve the list of posts including user, the list of posts is retrieve, but i havn't any data on the user except his id.
Response :
[
{
"content":"jksdjd",
"created_at":"2013-08-31T09:03:01Z",
"id":11,"title":"kdjs",
"updated_at":"2013-08-31T09:03:01Z",
"user_id":4
},
{
"content":"tez2",
"created_at":"2013-08-31T09:16:45Z",
"id":12,
"title":"test2",
"updated_at":"2013-08-31T09:16:45Z",
"user_id":4
}
]
By default a JSON response won't return any associated models. You need to specify the other models you want returned. So in your case, you can do this:
render json: #post => #post.to_json(:include => :user), status: :created, location: #post
Also see:
http://api.rubyonrails.org/classes/ActiveModel/Serializers/JSON.html
Rails Object Relationships and JSON Rendering
I have the following models in my Rails application:
class Transaction
belongs_to :category
has_one :group, :through => :category
class Category
belongs_to :group
has_many :transactions
class Group
has_many :categories
has_many :transactions, :through => :category
In my controller is the following:
#transactions = Transaction.includes(:category, :group).group("groups.id").sum("amount")
respond_to do |format|
format.json{
render :json => JSON.generate(#transactions.as_json(:include => [:category, :group]))
}
end
This produces the following json (A):
{"1":2000,"3":5000,"2":1000}
However, my goal is to produce something like this (B):
[{"group_id":1,"amount":2000},{"group_id":3,"amount":5000},{"group_id":2,"amount":1000}]
Any help on how I can go from A to B would be greatly appreciated.
Try:
def user_transactions
#transactions = Transaction.includes(:category, :group).group("groups.id").sum("amount")
respond_to do |format|
format.html
format.json do
render :json => custom_json_for(#transactions)
end
end
end
private
def custom_json_for(value)
list = value.map do |k,v|
{ :group_id => k,
:amount=> v
}
end
list.to_json
end
If you're doing a lot a JSON-serialization, I would recommend you to take a look at ActiveModelSerializers:
https://github.com/rails-api/active_model_serializers
I have the following classes:
class VideoChannel < ActiveRecord::Base
#Associations
belongs_to :video_playlist, :dependent => :destroy
VideoChannel.video_playlist_name
delegate :name, :id, :list_type, :list_id, :manual, :to => :video_playlist, :prefix => true
#validations
validates_presence_of :name
#After Functions
def after_create
video_playlist = VideoPlaylist.new(:name => self.name,
:list_type => "VideoChannel",
:list_id => self.id)
video_playlist.save
end
And :
class VideoPlaylist < ActiveRecord::Base
belongs_to :list, :polymorphic => true
has_many :video_channels, :dependent => :destroy
delegate :name, :id, :description, :to => :video_channel, :prefix => true
end
I'm trying to use the Rails Delegate function to create a link in the VideoChannel page that allows me to to link to the Video Playlist and edit the contents there. So the association is there and You can currently edit the playlists by going through the playlists section but we want to combine them. I can't seem to figure this out. Im also very new to Rails, still working through the guides etc.
Edit: Here's the view code
<%= link_to '<span class="pen icon"></span>Edit',
content_url(:controller =>"video_playlists", :id => channel.video_playlist_id, :action => "edit"),
:class => "button right" %>
Here are teh relevant pieces of the controllers:
class VideoChannelsController < ApplicationController
# GET /videochannels
# GET /videochannels.xml
def index
#video_channels = VideoChannel.roots(:order => 'order_num')
#video_channels_parents = #video_channels.group_by {:parent_id}
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => #video_channels }
end
end
# GET /videochannels/1
# GET /videochannels/1.xml
def show
#video_channel = VideoChannel.find(params[:id], :order => 'order_num')
respond_to do |format|
format.html # show.html.erb
format.xml { render :xml => #video_channel }
end
end
end
class VideoPlaylistsController < ApplicationController
# GET /video_playlists
# GET /video_playlists.xml
def index
if !params[:with].nil?
#video_playlists = VideoPlaylist.find(:all, :conditions => {:list_type => 'VideoShow'})
else
#video_playlists = VideoPlaylist.find(:all, :conditions => {:list_type => 'Section'})
end
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => #video_playlists }
end
end
# GET /video_playlists/1
# GET /video_playlists/1.xml
def show
#video_playlist = VideoPlaylist.find(params[:id], :include => [{:video_video_playlists => :video}, {:videos => :asset}, {:videos => :content_image}])
respond_to do |format|
format.html # show.html.erb
format.xml { render :xml => #video_playlist }
end
end
end
Where did the line
VideoChannel.video_playlist_name
Come from? What's it doing? You're also calling a method on the class not an instance (sort of - Ruby isn't quite like this, but it's enough to explain).
Anyway:
Delegate is really for avoiding lots of train wreck code like this:
fred.jim.bill.xxx
You've said that they belong to each other - the relationships look like they're the wrong way round. Why are you creating the parent from inside the child? How are you going to have many video channels belonging to a given playlist?
I think you need to look at build and the relationship names. To gat past me maybe misunderstanding your model, lets have switch to a product that has many stock items:
class Product < ActiveRecord::Base
has_many :stock_items
end
class StockItem < ActiveRecord::Base
belongs_to :product
end
This means that stock_item will have a column product_id.
So, say you're creating a product you'd do something like:
product.stock_items.build # :whatever the params are required
This automatically sets the id's for you and means you don't have to set id's. Then when you do product.save it will save all the related stock items too.
And in the view for this toy model, then if you were displaying one of the stock items, you'd use delegate to show the name of the product in the view without having to do lost of stock_item.product.name (for example).
I hope this helps.
I am having that problem that my model dont want to save. I have a token field input for tags.
I have followed this guide for the token input: http://railscasts.com/episodes/258-token-fields
I get this error when I try to create a new konkurrancer:
NoMethodError in Admin/konkurrancersController#create
undefined method `class_name' for nil:NilClass
Rails.root: C:/Rails/konkurranceportalen
Application Trace | Framework Trace | Full Trace
app/models/konkurrancer.rb:15:in `tag_tokens='
app/controllers/admin/konkurrancers_controller.rb:48:in `new'
app/controllers/admin/konkurrancers_controller.rb:48:in `create'
http://pastie.org/1834194
Request
Parameters:
{"utf8"=>"✓",
"authenticity_token"=>"yo7wcAQl81tx3zZpPP44ENPYzYRZLpgyYKY+HK3yFKM=",
"konkurrancer"=>{"name"=>"Vind en rejse",
"banner2"=>"asdasd",
"tracking"=>"sadasd",
"vaerdi"=>"12222",
"tid"=>"1 min",
"tag_tokens"=>"1",
"bedom"=>"2",
"kategori_id"=>"9",
"form"=>"Nyhedsbrev",
"partner"=>"Iqmedier",
"udtraekkes(3i)"=>"30",
"udtraekkes(2i)"=>"4",
"udtraekkes(1i)"=>"2011",
"udtraekkes(4i)"=>"08",
"udtraekkes(5i)"=>"26",
"arrangeor"=>"",
"note"=>""},
"commit"=>"Opret konkurrence"}
My konkurrancer model:
class Konkurrancer < ActiveRecord::Base
attr_accessible :name, :tag_tokens
has_many :tagsmenus
has_many :tags, :through => :tagsmenus
attr_reader :tag_tokens
def tag_tokens=(ids)
self.tag_ids = ids.split(",")
end
end
My tag model:
class Tag < ActiveRecord::Base
has_many :tagsmenus
has_many :konkurrancers, :through => :tagsmenus
has_friendly_id :name, :use_slug => true
before_save :assign_cached_slug, :unless => :cached_slug?
protected
def assign_cached_slug
self.cached_slug = self.name.gsub(/\s+/, '_').gsub(/[^\w\-]/, '')
end
end
My tagmenu model:
class Tagsmenu < ActiveRecord::Base
end
My controller:
def new
#konkurrancer = Konkurrancer.new
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => #konkurrancer }
end
end
# POST /konkurrancers
# POST /konkurrancers.xml
def create
#konkurrancer = Konkurrancer.new(params[:konkurrancer])
respond_to do |format|
if #konkurrancer.save
format.html { redirect_to(:admin_konkurrancers, :notice => 'Konkurrancer was successfully created.') }
format.xml { render :xml => :admin_konkurrancers, :status => :created, :location => #konkurrancer }
else
format.html { render :action => "new" }
format.xml { render :xml => #konkurrancer.errors, :status => :unprocessable_entity }
end
end
end
I have created the join table and the model and also added the relation to my tag model.
Your model has some conflicting statements. You first define:
attr_accessor ... :tag_tokens
then later have:
attr_reader :tag_tokens
which is not necessary given the first line or vice versa given that later you have a deinition for the setter:
def tag_tokens(ids)
self.tag_ids = ids.split(',')
end
I don't see tag_ids defined either given it is not a column in your table. You should probably remove the attr_accessor definition for the tag_tokens and then define the tag_ids method for starters.
class Tagsmenu < ActiveRecord::Base
belongs_to :konkurrancer
belongs_to :tag
end