I have two models post.rb and attachment.rb with the following associations:
class Attachment < ApplicationRecord
belongs_to :post, optional: true
end
class Post < ApplicationRecord
has_many :attachments, :dependent => :destroy
end
This is what I have inside the controller action where the view is:
def results_search
if params[:search]
#attachment = Attachment.all
#posts = Post.search(params[:search])
end
end
I'm trying to do this <% #posts.attachments.each do |post|%> but I'm getting the following error undefined method attachments' for #<Post::ActiveRecord_Relation:0x007fa673bef9d0>
I want to loop through all the results from the search (#posts) and show the results alongside the attachments that belong to each post. Each attachment has a post_id assigned to it. Any ideas how I can implement this?
You're going to want to do something like:
#posts.each do |post|
# do some stuff with post (show name, content, etc.)
post.attachments.each do |attachment|
# do stuff with attachment (show, etc.)
end
end
What it really looks like depends on where you're doing this (view?) and what tools you're using (vanilla erb, slim, haml, etc.).
Also, you're going to want to do some eager loading so you don't end up in N+1 land.
Related
Working on an app in rails 4 that has Invoices and Clients as Models - I already set the associations between them as you can see in the snippets below from both Models, but can't achieve how to display for instance the Client.name within an Invoice show view.
Through Rails console, if I do 'Invoice.last.client.name' - I can see the client name - but once I try to show that same thing in the view with this piece of code:
<% #invoices.each do |invoice| %>
<%= invoice.client.name %>
<% end %>
I get this error undefined method `name' for nil:NilClass
Invoice.rb (Model)
class Invoice < ActiveRecord::Base
belongs_to :client
acts_as_schedulable :schedule
# accepts_nested_attributes_for :clients
end
Client.rb (Model)
class Client < ActiveRecord::Base
has_many :invoices
validates_formatting_of :email, using: :email
end
Tried adding doing something with nested attributes and adding the 'name' method in the Invoice controller, but don't know what I'm doing wrong. For more reference, I have included the whole Invoice controller in this pastebin link.
def name
#invoice = Invoice.client.name
end
It could be that you have an Invoice instant without a client. I would start by confirming in the console that all the Invoices have a client e.g.
Invoice.all.reject{|invoice| invoice.client}.count
If the answer is not zero, that's your problem.
Also the name method you've posted is incorrect and would throw an error. You're calling a class method 'client' on the Invoice class.
Hello im trying to add some records to my database with this model
class Colleagueship < ActiveRecord::Base
belongs_to :employee
belongs_to :colleague, :class_name => 'Employee'
end
class Employee < ActiveRecord::Base
has_many :colleagueships
has_many :colleagues, :through => :colleagueships
# ...
end
but i have no idea in how to start a new form to create new records
im thinking to try something like
def new
employee = ## gotta get the id here in the form
#colleagueship = employee.colleagueships.build(:colleague_id => params[:colleague_id])
#colleagueship.save
end
what do you think? how do i achieve this with a post http method? do i have to save the employee variable with the request and add the employee_id there?
In the controller
def new
end
def create
# inspect submitted params here
puts params
if colleagueship.save
# etc etc
else
# error
end
end
private
def employee
#employee = Employee.find_by(params[:employee_id])
end
def colleagueship
#colleagueship = employee.colleageships.build
end
helper_method :employee, :colleagueship
Your routes should be nested to provide the key you'll use to find the employee.
resources :employees do
# this will generate /employees/:employee_id/colleagues/:id
resources :colleagueships
end
In your view, you will probably use the form_tag helper, as it's easier to customize forms with whatever fields you want, especially if you're avoiding accepts_nested_attributes which you should. You can also include a hidden_field_tag with employee_id if you aren't nested your routes.
= form_tag new_employee_colleague_path do
= text_field_tag 'colleageship[name]', placeholder: 'something...'
Something along these lines should work. Make sure to inspect the params hash to see that the values are formatted correctly.
I have a class called Quote which has_many :line_items, as: :line_itemable (line_items are polymorphic). A quote must have at least one line_item upon creation, so in my Quote creation form I have a section dedicated to adding line items. My routes look like this:
resources :quotes, shallow: true do
resources :line_items
end
which means my routes look like this:
POST /quotes/:quote_id/line_items(.:format) line_items#create
new_quote_line_item GET /quotes/:quote_id/line_items/new(.:format) line_items#new
In the line items section of the quote form I have a button that, when clicked, links to the new_quote_line_item controller action to render a line_item creation modal. My issue is that since the quote hasn't been created yet it doesn't have :quote_id to use in the path. How can I go about achieving this the Rails Way™? I was considering using ajax but I'm not sure if that is overkill for this situation. Thanks for your help!
You should user accepts_nested_attributes_for method in your model to accept attributes for LineItem and fields_for helper
Your model should looks like:
class Quote < ActiveRecord::Base
accepts_nested_attributes_for :line_item
...
end
And you template like:
form_for #quote do |f|
f.fields_for :line_items do |f2|
...
end
...
end
Ajax
You wouldn't need ajax functionality for this - Ajax only allows you to pull data from the server asynchronously, which essentially means you don't have to reload the page.
--
Nested Attributes
What you're looking for, as alluded to by atomAltera sounds like accepts_nested_attributes_for - which allows you to create dependent models from the parent
It sounds to me that you'll need to create a quote before you try and populate line_items, which is actually quite simple using ActiveRecord:
#app/models/quote.rb
Class Quote < ActiveRecord::Base
has_many :line_items
accepts_nested_attributes_for :line_items
end
#app/controllers/quotes_controller.rb
Class QuotesController < ApplicationController
def new
#quote = Quote.new
#quote.line_items.build
end
def create
#quote = Quote.new(quote_params)
#quote.save
end
private
def quote_params
params.require(:quote).permit(:quote, :attributes, :new, line_items_attributes: [:line, :items, :attributes])
end
end
--
If you need any further information, please let me know!!
Basically I have a Shop, Category and a join model ShopCategory with additional attributes
class Shop
has_many :shop_categories
has_many :categories, through: :shop_categories
class Category
has_many :shop_categories
has_many :shops, through: :shop_categories
class ShopCategory
belongs_to :shop
belongs_to :category
I have a shop form which I'd like to create or update the shop through it.
My first thought is to create a virtual attribute called :categories and to have the model handle the setter and getter through it, something like this (pseudocode for simplicity):
def categories=(cats)
cats.each do |c|
check if a ShopCategory exists with this shop (self) and that category.
if doesn't exist, create one, if exists ignore
for all the categories in self that weren't touched, delete that ShopCategory
end
end
but I feel this would cause problems in the long run because of the connection of 3 models and not though a controller
However, I can't seem to think of a simple way to have a create and update methods in the shops_controller for handling this
def update
#shop = Shop.find params[:id]
cats = params[:shop].delete :categories
#shop.update_attributes(shop_params)
## should I have a category update method here? How would I handle errors? This gets complicated
end
It sounds like you want a nested model form, for editing both a Shop and its associated ShopCategories.
Basically, what it entails is on the form for your Shop, you can simply iterate over the associated ShopCategories and print out fields for them, to edit them all together. Rails will automatically handle it all, as long as the parameters are structured correctly.
https://github.com/nathanvda/cocoon is a gem for making nested model forms easier.
There is also a tutorial on Railscasts:
http://railscasts.com/episodes/196-nested-model-form-revised
Collections
I don't know how experienced you are with Ruby on Rails, but you may wish to look at some of the documentation pertaining to collections
What you're looking at is how to populate your collections - which is actually relatively simple:
#app/controllers/shops_controller.rb
Class ShopsController < ApplicationController
def create
#shop = Shop.new(shop_params)
#shop.save
end
private
def shop_params
params.require(:shop).permit(:your, :attributes, category_ids: [])
end
end
This will allow you to use the following form:
#app/views/shops/new.html.erb
<%= form_for #shop do |f| %>
<% Category.all.each do |category| %>
<%= f.check_box :category_ids, category.id %>
<% end %>
<% end %>
--
Modularity
In terms of validating your collections for uniqueness, you will be best using DB, or Association-level validation:
class Shop
has_many :categories, -> { uniq }, through: :shop_categories
This will essentially create only unique categories for your shop, which you can populate with the method described above.
I have users, posts and comments. User can post only one comment to each post.
class User < ActiveRecord::Base
has_many :posts
has_many :comments
end
class Post < ActiveRecord::Base
has_many :comments
belongs_to :user
end
class Comment < ActiveRecord::Base
belongs_to :user
belongs_to :post
end
On userpage (http://host/users/1 for example) I want to show all posts where the given user has commented. Each post then will have all other comments.
I can do something like this in my User controller:
def show
#user = User.find(params[:user_id])
#posts = []
user.comments.each {|comment| #posts << comment.post}
end
This way I will find User, then all his comments, then corresponding post to each comment, and then (in my view) for each post I will render post.comments. I'm totally new in Rails, so I can do this =) But I think it's somehow bad and there is a better way to do this, maybe I should use scopes or named_scopes (don't know yet what this is, but looks scary).
So can you point me out to the right direction here?
You could define an association which retrieves all the posts with comments in a single query. Keeping it in the model reduces the complexity of your controllers, enables you to reuse the association and makes it easier to unit test.
class User < ActiveRecord::Base
has_many :posts_with_comments, :through => :comments, :source => :post
# ...
end
:through is an option for has_many to specify a join table through which to perform the query. We need to specify the :source as Rails wouldn't be able to infer the source from :post_with_comments.
Lastly, update your controller to use the association.
def show
#user = User.find(params[:user_id])
#posts = #user.posts_with_comments
end
To understand more about :through and :source take a look at the documentation.
When you got the user, you have the associations to his posts and each post has his comments.
You could write:
(I don't know the names of your table fields, so i named the text text)
# In Controller
#user = User.find(params[:user_id]).include([:posts, :comments])
# In View
#user.posts.each do |post|
post.text
# Comments to the Post
post.comments.each do |comment|
comment.text
end
end
I haven't tested the code, so there could be some errors.