Building a validator that has to check multiple siblings who belong to the same (option) parent.
class Optionrate < ActiveRecord::Base
belongs_to :option
attr_accessible :from, :to, :option_id
validates_presence_of :from, :to
validate :not_overlap
scope :overlaps, ->(from, to) do
where "((from <= ?) and (to >= ?))", to, from
end
def overlaps?
overlaps.exists?
end
def overlaps
siblings.overlaps from, to
end
def not_overlap
errors.add(:key, t('overlap_message')) if overlaps?
end
def siblings
Optionrate.where('option_id = ?', option_id).all
end
is generating an error: "undefined method `overlaps' for []:Array" referring to statement
siblings.overlaps from, to
The fact that siblings is plural makes me assume it is expecting an array, so that's an oddity.
[Another was that the where statement was not accepting *where('option_id = ?', params[:option_id])* whence the record has yet to be created as the validation has not completed]
Please try to run the code after removing .all from Optionrate.where('option_id = ?', option_id).all because when you are using .Where then there is no need to use .all method.
Or
Take a look on following url for reference
http://guides.rubyonrails.org/3_2_release_notes.html#active-record
Related
Say I am keeping track of email correspondances. An enquiry (from a customer) or a reply (from a supporter) is embedded in the order the two parties are corresponding about. They share the exact same logic when put into the database.
My problem is that even though I use the same logic, the object classes are different, the model fields I need to call are different, and the method names are different as well.
How do I put methods and objects references in before I actually have to use them? Does a "string_to_method" method exists or something like that?
Sample code with commentaries:
class Email
include Mongoid::Document
field :from, type: String
field :to, type: String
field :subject, type: String
belongs_to :order, :inverse_of => :emails
def start
email = Email.create!(:from => "sender#example.com", :to => "recipient#example.com", :subject => "Hello")
from_or_to = from # This represents the database field from where I later on will fetch the customers email address. It is either from or to.
enquiries_or_replies = enquiries # This represents a method that should later be called. It is either enquiries or replies.
self.test_if_enquiry_or_reply(from_or_to, enquiries_or_replies)
end
def test_if_enquiry_or_reply(from_or_to, enquiries_or_replies)
order = Order.add_enquiry_or_reply(self, from_or_to, enquiries_or_replies)
self.order = order
self.save
end
end
class Order
include Mongoid::Document
field :email_address, type: String
has_many :emails, :inverse_of => :order
embeds_many :enquiries, :inverse_of => :order
embeds_many :replies, :inverse_of => :order
def self.add_enquiry_or_reply(email, from_or_to, enquiries_or_replies)
order = Order.where(:email_address => email.from_or_to).first # from_or_to could either be from or to.
order.enquiries_or_replies.create!(subject: email.subject) # enquiries_or_replies could either be enquiries or replies.
order
end
end
Judging by the question and the code sample, it sounds like you are mixing concerns too much. My first suggestion would be to re-evaluate your method names and object structure. Ambiguous names like test_if_thing1_or_thing2 and from_or_to (it should just be one thing) will make it very hard for others, and your future self, to understand the code laster.
However, without diverging into a debate on separation of concerns, you can change the methods you call by using public_send (or the private aware send). So you can do
order.public_send(:replies).create!
order.public_send(:enquiries).create!
string to method does exist, it's called eval
so, you could do
method_name = "name"
eval(method_name) #calls the name method
I've setup a nested form in my rails 3.2.3 app, it's working fine, my models are:
class Recipe < ActiveRecord::Base
attr_accessible :title, :description, :excerpt, :date, :ingredient_lines_attributes
has_and_belongs_to_many :ingredient_lines
accepts_nested_attributes_for :ingredient_lines
end
and:
class IngredientLine < ActiveRecord::Base
attr_accessible :ingredient_id, :measurement_unit_id, :quantity
has_and_belongs_to_many :recipes
belongs_to :measurement_unit
belongs_to :ingredient
end
As above, a Recipe can have multiple IngredientLines and vice versa.
What I'm trying to avoid is record duplication on IngredienLine table.
For example imagine that for recipe_1 an IngredientLine with {"measurement_unit_id" => 1, "ingredient_id" => 1, "quantity" => 3.5} is associated, if for recipe_5 the IngredientLine child form is compiled by the user with the same values, I don't want a new record on IngredientLine table, but only a new association record in the join table ingredient_lines_recipes.
Note that currently I dont't have any IngredientLine controller as saving and updating IngredientLines is handled by nested form routines. Even my Recipe controller is plain and standard:
class RecipesController < ApplicationController
respond_to :html
def new
#recipe = Recipe.new
end
def create
#recipe = Recipe.new(params[:recipe])
flash[:notice] = 'Recipe saved.' if #recipe.save
respond_with(#recipe)
end
def destroy
#recipe = Recipe.find(params[:id])
#recipe.destroy
respond_with(:recipes)
end
def edit
respond_with(#recipe = Recipe.find(params[:id]))
end
def update
#recipe = Recipe.find(params[:id])
flash[:notice] = 'Recipe updated.' if #recipe.update_attributes(params[:recipe])
respond_with(#recipe)
end
end
My guess is that should be enough to override the standard create behavior for IngredientLine with find_or_create, but I don't know how to achieve it.
But there's another important point to take care, imagine the edit of a child form where some IngredientLines are present, if I add another IngredientLine, which is already stored in IngredientLine table, rails of course should not write anything on IngredientLine table, but should also distinguish between child records already associated to the parent, and the new child record for which needs to create the relation, writing a new record on the join table.
Thanks!
in Recipe model redefine method
def ingredient_lines_attributes=(attributes)
self.ingredient_lines << IngredientLine.where(attributes).first_or_initialize
end
Old question but I had the same problem. Forgot to add :id to white list with rails 4 strong_parameters.
For example:
widgets_controller.rb
def widget_params
params.require(:widget).permit(:name, :foos_attributes => [:id, :name, :_destroy],)
end
widget.rb
class Widget < ActiveRecord::Base
has_many :foos, dependent: :destroy
accepts_nested_attributes_for :foos, allow_destroy: true
end
foo.rb
class Foo < ActiveRecord::Base
belongs_to :widget
end
I have run into a similar situation and found inspiration in this answer. In short, I don't worry about the duplication of nested models until save time.
Translated to your example, I added autosave_associated_records_for_ingredient_lines to Recipe. It iterates through ingredient_lines and performs a find_or_create as your intuition said. If ingredient_lines are complex, Yuri's first_or_initialize approach may be cleaner.
I believe this has the behavior you're looking for: nested models are never duplicated, but editing one causes a new record rather than updating a shared one. There is the strong possibility of orphaned ingredient_lines but if that's a serious concern you could choose to update if that model has only one recipe with an id that matches the current one.
having this code block of an example rails model class:
class Block < ActiveRecord::Base
has_many :bricks, :autosave => true
def crunch
bricks.each do |brick|
if brick.some_condition?
brick.name = 'New data'
brick.save # why do I have to call this?
end
end
end
end
class Brick < ActiveRecord::Base
belongs_to :block, :autosave => true
end
I found that the only way to make sure the changes within the associated objects get saved for me, was to call brick.save manually. Even thought I use :autosave => true
Why?
Probably the autosave option has a misleading name. By the way, it's the expected behaviour. The option is meant for association. So if you modify an object in a relation and save the other object then ActiveRecord saves the modified objects. So, in your case, you could change your code to:
def crunch
bricks.each do |brick|
if brick.some_condition?
brick.name = 'New data'
end
end
save # saving the father with autosave should save the children
end
You could use any of the helper methods available: update_attribute, update_attributes, update_column...
More info: Rails: update_attribute vs update_attributes
class State < ActiveRecord::Base
has_many :cities
end
class City < ActiveRecord::Base
belongs_to :state
has_many :companies
end
class Company < ActiveRecord::Base
belongs_to :city
end
I'm trying to list all states, and their respective cities, that contain at least one company registered. My first try was the following query:
states = State.joins(:cities => :companies).includes(:cities)
Which works, but I end up getting duplicates if a state has more than one city with companies in it. I then changed the query to:
states = State.joins(:cities => :companies).includes(:cities).select("distinct(states.id)")
This query almost works. I have access to the cities (states[0].cities), and there are no duplicates, but if I try to access an attribute from the State object, I get the following error:
ruby-1.9.2-p290 :056 >states[0].name
ActiveModel::MissingAttributeError: missing attribute: name
How can I solve this?
Thanks in advance
Your select statement overrides the default (SELECT * FROM ... becomes SELECT distinct(state.id) FROM...) so the results don't include the columns of your state table (where the attributes are inferred from). Try changing your select method to the following:
.select("distinct(states.id), states.*")
Consider the following parent/child relationship where Parent is 1..n with Kids (only the relevant stuff here)...
class Parent < ActiveRecord::Base
# !EDIT! - was missing this require originally -- was the root cause!
require "Kid"
has_many :kids, :dependent => :destroy, :validate => true
accepts_nested_attributes_for :kids
validates_associated :kids
end
class Kid < ActiveRecord::Base
belongs_to :parent
# for simplicity, assume a single field: #item
validates_presence_of :item, :message => "is expected"
end
The validates_presence_of methods on the Kid model works as expected on validation failure, generating a final string of Item is expected per the custom message attribute supplied.
But if try validates_with, instead...
class Kid < ActiveRecord::Base
belongs_to :parent
validates_with TrivialValidator
end
class TrivialValidator
def validate
if record.item != "good"
record.errors[:base] << "Bad item!"
end
end
end
...Rails returns a NameError - uninitialized constant Parent::Kid error following not only an attempt to create (initial persist) user data, but also when even attempting to build the initial form. Relevant bits from the controller:
def new
#parent = Parent.new
#parent.kids.new # NameError, validates_* methods called within
end
def create
#parent = Parent.new(params[:parent])
#parent.save # NameError, validates_* methods called within
end
The error suggests that somewhere during model name (and perhaps field name?) resolution for error message construction, something has run afoul. But why would it happen for some validates_* methods and not others?
Anybody else hit a wall with this? Is there some ceremony needed here that I've left out in order to make this work, particularly regarding model names?
After a few hours away, and returning fresh -- Was missing require "Kid" in Parent class. Will edit.