I might be doing this wrong overall, but maybe someone will be able to chirp in and help out.
Problem:
I want to be able to build a relationship on an unsaved Object, such that this would work:
v = Video.new
v.title = "New Video"
v.actors.build(:name => "Jonny Depp")
v.save!
To add to this, these will be generated through a custom method, which I'm attempting to modify to work, that does the following:
v = Video.new
v.title = "Interesting cast..."
v.actors_list = "Jonny Depp, Clint Eastwood, Rick Moranis"
v.save
This method looks like this in video.rb
def actors_list=value
#Clear for existing videos
self.actors.clear
value.split(',').each do |actorname|
if existing = Actor.find_by_name(actorname.strip)
self.actors << existing
else
self.actors.build(:name => actorname.strip)
end
end
end
What I expect
v.actors.map(&:name)
=> ["Jonny Depp", "Clint Eastwood", "Rick Moranis"]
Unfortunatey, these tactics neither create an Actor nor the association. Oh yeah, you might ask me for that:
in video.rb
has_many :actor_on_videos
has_many :actors, :through => :actor_on_videos
accepts_nested_attributes_for :actors
I've also tried modifying the actors_list= method as such:
def actors_list=value
#Clear for existing videos
self.actors.clear
value.split(',').each do |actorname|
if existing = Actor.find_by_name(actorname.strip)
self.actors << existing
else
self.actors << Actor.create!(:name => actorname.strip)
end
end
end
And it creates the Actor, but I'd rather not create the Actor if the Video fails on saving.
So am I approaching this wrong? Or have I missed something obvious?
Try this:
class Video < ActiveRecord::Base
has_many :actor_on_videos
has_many :actors, :through => :actor_on_videos
attr_accessor :actors_list
after_save :save_actors
def actors_list=names
(names.presence || "").split(",").uniq.map(&:strip).tap do |new_list|
#actors_list = new_list if actors_list_changes?(new_list)
end
end
def actors_list_changes?(new_list)
new_record? or
(actors.count(:conditions => {:name => new_list}) != new_list.size)
end
# save the actors in after save.
def save_actors
return true if actors_list.blank?
# create the required names
self.actors = actors_list.map {|name| Actor.find_or_create_by_name(name)}
true
end
end
You cannot assign a child to an object with no id. You will need to store the actors in your new video object and save those records after the video has been saved and has an id.
Related
I have 3 models :
Product
has_many :variants
Variant
has_many :stocks
belongs_to :product
Stock
belongs_to :variant
I need to retrive the Variant where Stock is not empty
I tried this way but this does not work as expected... as it is empty it is not nil...
#product.variants.includes(:stocks).where.not(stocks: nil)
More simpler version of what you did....
using Has Many association reference
and in my Product Controller
def show
#product_size_options = []
#product.variants.map do |var|
##this will make sure that only persisted stocks comes out
if var.stock_ids.size > 0
#product_size_options << var
end
end
end
The above code can also be written in one line =>
#product.variants.map { |var| var if var.stock_ids.size > 0 }.compact.flatten
Hope it helps
I did find a working solution in a different way:
In my Variant model
def has_stock
self.stocks.empty? ? false : true
end
and in my Product Controller
def show
#product_size_options = []
#product.variants.map do |var|
if var.has_stock == true
#product_size_options << var
end
end
end
I have a record called Feeds that contains the field 'last_visited' and 'last_modified', both are timestamps.
I'm trying to render a list in a view of alls Feeds where last_modified > last_visited.
I currently have this:
Controller
#feeds = #user.feeds
#feeds_hot = #feeds.where(['#feeds.last_modified > ?', #feeds.last_visited])
Have a feeling I'm way off track here. Should I also being using a model class to do this?
Any helps is greatly appreciated.
Edit:
Here's my model
class Feed < ActiveRecord::Base
attr_accessible :feed_id, :feed_url, :last_modified, :title, :url, :last_visited, :user_id
belongs_to :user
scope :hottest, lambda {where('last_modified > ?', :last_visited)}
def fetch_feed!
feed = Feedzirra::Feed.fetch_and_parse(feed_url) # probably want some eror handling here
self.title = feed.title
self.url = feed.url
self.last_modified = feed.last_modified
self.last_visited = feed.last_modified
self #or nil if you like
end
def self.check_for_update(feed)
fetched_feed = Feedzirra::Feed.fetch_and_parse(feed.feed_url)
entry = fetched_feed.entries.first
feed.last_modified = entry.published
end
def update_visit_date!
date = Time.now
update_attribute(:last_visited, date)
self
end
end
Edit
Updated code
Controller
def home
#user = current_user
#feeds = #user.feeds
#feeds_hot = #feeds.hottest
end
Model
attr_accessible :feed_id, :feed_url, :last_modified, :title, :url, :last_visited, :user_id
belongs_to :user
scope :hottest, lambda {where("'last_modified' > ?", 'last_visited')}
View
%ol.feeds.feeds_hot
- #feeds_hot.each do |feed|
%li.feed.hot[feed]
= render :partial => 'feeds/feed_link', :locals => {:feed => feed}
Unfortunately it's still not rendering the hot feeds in the view when I have a feed with the following data:
Last Modified 2013-06-14 23:49:07 UTC
Last Visited 2013-06-14 23:47:55 UTC
Last Modified is a few hours > than Last Visited
If you're looking to get a list of all feeds that have been modified more recently than the most recent visit on any feed, the following will work:
last_visit = Feed.order("last_visited").last.last_visited
#feeds = #user.feeds
#hot_feeds = Feed.where("last_modified > ?", last_visited)
EDIT:
Based on your comments and a re-reading of your question, the code posted above will not accomplish what you're trying to do. Since you're trying to get a list of all invites where each has been modified since it was last visited, you'll want to create a model scope to do the lookup with ActiveRecord. The following code should work:
# app/models/feed.rb
class Feed < ActiveRecord::Base
scope :hottest, lambda {where('last_modified > ?', :last_visited)}
end
Then, you can run the following in a console, controller, or view:
#user.invites.hottest
#=> array of all the user's invites that have been modified more recently than they have been viewed
I use Rails 3.0.6 with mongoID 2.0.2. Recently I encountered an issue with save! method when overriding setter (I am trying to create my own nested attributes).
So here is the model:
class FeedItem
include Mongoid::Document
has_many :audio_refs
def audio_refs=(attributes_array, binding)
attributes_array.each do |attributes|
if attributes[:audio_track][:id]
self.audio_refs.build(:audio_track => AudioTrack.find(attributes[:audio_track][:id]))
elsif attributes[:audio_track][:file]
self.audio_refs.build(:audio_track => AudioTrack.new(:user_id => attributes[:audio_track][:user_id], :file => attributes[:audio_track][:file]))
end
end
if !binding
self.save!
end
end
AudioRef model (which is just buffer between audio_tracks and feed_items) is:
class AudioRef
include Mongoid::Document
belongs_to :feed_item
belongs_to :audio_track
end
And AudioTrack:
class AudioTrack
include Mongoid::Document
has_many :audio_refs
mount_uploader :file, AudioUploader
end
So here is the spec for the FeedItem model which doesn`t work:
it "Should create audio_track and add audio_ref" do
#audio_track = Fabricate(:audio_track, :user_id => #author.id, :file => File.open("#{Rails.root}/spec/stuff/test.mp3"))
#feed_item= FeedItem.new(
:user => #author,
:message => {:body => Faker::Lorem.sentence(4)},
:audio_refs => [
{:audio_track => {:id => #audio_track.id}},
{:audio_track => {:user_id => #author.id, :file => File.open("#{Rails.root}/spec/stuff/test.mp3")}}
]
)
#feed_item.save!
#feed_item.reload
#feed_item.audio_refs.length.should be(2)
end
As you can see, the reason I am overriding audio_refs= method is that FeedItem can be created from existing AudioTracks (when there is params[:audio_track][:id]) or from uploaded file (params[:audio_track][:file]).
The problem is that #feed_item.audio_refs.length == 0 when I run this spec, i.e. audio_refs are not saved. Could you please help me with that?
Some investigation:
1) binding param is "true" by default (this means we are in building mode)
I found a solution to my problem but I didnt understand why save method doesnt work and didn`t make my code work. So first of all let me describe my investigations about the problem. After audio_refs= is called an array of audio_refs is created BUT in any audio_ref is no feed_item_id. Probably it is because the feed_item is not saved by the moment.
So the solution is quite simple - Virtual Attributes. To understand them watch corresponding railscasts
So my solution is to create audio_refs by means of callback "after_save"
I slightly changed my models:
In FeedItem.rb I added
attr_writer :audio_tracks #feed_item operates with audio_tracks array
after_save :assign_audio #method to be called on callback
def assign_audio
if #audio_tracks
#audio_tracks.each do |attributes|
if attributes[:id]
self.audio_refs << AudioRef.new(:audio_track => AudioTrack.find(attributes[:id]))
elsif attributes[:file]
self.audio_refs << AudioRef.new(:audio_track => AudioTrack.new(:user_id => attributes[:user_id], :file => attributes[:file]))
end
end
end
end
And the spec is now:
it "Should create audio_track and add audio_ref" do
#audio_track = Fabricate(:audio_track, :user_id => #author.id, :file => File.open("#{Rails.root}/spec/stuff/test.mp3"))
#feed_item= FeedItem.new(
:user => #author,
:message => {:body => Faker::Lorem.sentence(4)},
:audio_tracks => [
{:id => #audio_track.id},
{:user_id => #author.id, :file => File.open("#{Rails.root}/spec/stuff/test.mp3")}
]
)
#feed_item.save!
#feed_item.reload
#feed_item.audio_refs.length.should be(2)
end
And it works fine!!! Good luck with your coding)
Check that audio_refs=() is actually being called, by adding debug output of some kind. My feeling is that your FeedItem.new() call doesn't use the audio_refs=() setter.
Here's the source code of the ActiveRecord::Base#initialize method, taken from APIdock:
# File activerecord/lib/active_record/base.rb, line 1396
def initialize(attributes = nil)
#attributes = attributes_from_column_definition
#attributes_cache = {}
#new_record = true
#readonly = false
#destroyed = false
#marked_for_destruction = false
#previously_changed = {}
#changed_attributes = {}
ensure_proper_type
populate_with_current_scope_attributes
self.attributes = attributes unless attributes.nil?
result = yield self if block_given?
_run_initialize_callbacks
result
end
I don't currently have an environment to test this, but it looks like it's setting the attributes hash directly without going through each attribute's setter. If that's the case, you'll need to call your setter manually.
Actually, I think the fact you're not getting an exception for the number of arguments (binding not set) proves that your setter isn't being called.
I'm learning new tricks all the time and I'm always on the lookout for better ideas.
I have this rather ugly method. How would you clean it up?
def self.likesit(user_id, params)
game_id = params[:game_id]
videolink_id = params[:videolink_id]
like_type = params[:like_type]
return false if like_type.nil?
if like_type == "videolink"
liked = Like.where(:user_id => user_id, :likeable_id => videolink_id, :likeable_type => "Videolink").first unless videolink_id.nil?
elsif like_type == "game"
liked = Like.where(:user_id => user_id, :likeable_id => game_id, :likeable_type => "Game").first unless game_id.nil?
end
if liked.present?
liked.amount = 1
liked.save
return true
else # not voted on before...create Like record
if like_type == "videolink"
Like.create(:user_id => user_id, :likeable_id => videolink_id, :likeable_type => "Videolink", :amount => 1)
elsif like_type == "game"
Like.create(:user_id => user_id, :likeable_id => game_id, :likeable_type => "Game", :amount => 1)
end
return true
end
return false
end
I would do something like:
class User < ActiveRecord::Base
has_many :likes, :dependent => :destroy
def likes_the(obj)
like = likes.find_or_initialize_by_likeable_type_and_likeable_id(obj.class.name, obj.id)
like.amount += 1
like.save
end
end
User.first.likes_the(VideoLink.first)
First, I think its wrong to deal with the "params" hash on the model level. To me its a red flag when you pass the entire params hash to a model. Thats in the scope of your controllers, your models should have no knowledge of the structure of your params hash, imo.
Second, I think its always cleaner to use objects when possible instead of class methods. What you are doing deals with an object, no reason to perform this on the class level. And finding the objects should be trivial in your controllers. After all this is the purpose of the controllers. To glue everything together.
Finally, eliminate all of the "return false" and "return true" madness. The save method takes care of that. The last "return false" in your method will never be called, because the if else clause above prevents it. In my opinion you should rarely be calling "return" in ruby, since ruby always returns the last evaluated line. In only use return if its at the very top of the method to handle an exception.
Hope this helps.
I'm not sure what the rest of your code looks like but you might consider this as a replacement:
def self.likesit(user_id, params)
return false unless params[:like_type]
query = {:user_id => user_id,
:likeable_id => eval("params[:#{params[:like_type]}_id]"),
:likeable_type => params[:like_type].capitalize}
if (liked = Like.where(query).first).present?
liked.amount = 1
liked.save
else # not voted on before...create Like record
Like.create(query.merge({:amount => 1}))
end
end
I assume liked.save and Like.create return true if they are succesful, otherwise nil is returned. And what about the unless game_id.nil? ? Do you really need that? If it's nil, it's nil and saved as nil. But you might as well check in your data model for nil's. (validations or something)
Is there a way to find all Polymorphic models of a specific polymorphic type in Rails? So if I have Group, Event, and Project all with a declaration like:
has_many :assignments, :as => :assignable
Can I do something like:
Assignable.all
...or
BuiltInRailsPolymorphicHelper.all("assignable")
That would be nice.
Edit:
... such that Assignable.all returns [Event, Group, Product] (array of classes)
There is no direct method for this. I wrote this monkey patch for ActiveRecord::Base.
This will work for any class.
class ActiveRecord::Base
def self.all_polymorphic_types(name)
#poly_hash ||= {}.tap do |hash|
Dir.glob(File.join(Rails.root, "app", "models", "**", "*.rb")).each do |file|
klass = File.basename(file, ".rb").camelize.constantize rescue nil
next unless klass.ancestors.include?(ActiveRecord::Base)
klass.
reflect_on_all_associations(:has_many).
select{ |r| r.options[:as] }.
each do |reflection|
(hash[reflection.options[:as]] ||= []) << klass
end
end
end
#poly_hash[name.to_sym]
end
end
Now you can do the following:
Assignable.all_polymorphic_types(:assignable).map(&:to_s)
# returns ['Project', 'Event', 'Group']
You can also try this way.cause above solution doesn't work for me cause i had some mongo's model.
def get_has_many_associations_for_model(associations_name, polymorphic=nil)
associations_name = associations_name.to_s.parameterize.underscore.pluralize.to_sym
active_models = ActiveRecord::Base.descendants
get_model = []
active_models.each do |model|
has_many_associations =model.reflect_on_all_associations(:has_many).select{|a|a.name==associations_name }
has_many_associations = has_many_associations.select{ |a| a.options[:as] == polymorphic.to_s.to_sym} if polymorphic.present?
get_model << model if has_many_associations.present?
end
get_model.map{|a| a.to_s}
end
Anb call it like
get_has_many_associations_for_model("assignments", "assignable")
Here Second parameters is optional for if you want polymorphic records than pass it otherwise leave it as blank.
It will Return Array of Model name as String.
Harish Shetty's solution will not work for namespaced model files which are not stored directly in Rails.root/app/models but in a subdirectory. Although it correctly globs files in subdirectories, it then fails to include the subdir when turning the file name into a constant. The reason for this is, that the namespacing subdir is removed by this line:
klass = File.basename(file, ".rb").camelize.constantize rescue nil
Here is what I did to retain the namespacing subdir:
file.sub!(File.join(Rails.root, "app", "models"), '')
file.sub!('.rb', '')
klass = file.classify.constantize rescue nil
Here's the full modified solution:
def self.all_polymorphic_types(name)
#poly_hash ||= {}.tap do |hash|
Dir.glob(File.join(Rails.root, "app", "models", "**", "*.rb")).each do |file|
file.sub!(File.join(Rails.root, "app", "models"), '')
file.sub!('.rb', '')
klass = file.classify.constantize rescue nil
next unless klass.ancestors.include?(ActiveRecord::Base)
klass.
reflect_on_all_associations(:has_many).
select{ |r| r.options[:as] }.
each do |reflection|
(hash[reflection.options[:as]] ||= []) << klass
end
end
end
#poly_hash[name.to_sym]
end
Now, the method will turn /models/test/tensile.rb correctly into Test::Tensile before reflecting on its associations.
Just a minor improvement, all credit still goes to Harish!
I created a polymorphic model class with a method 'all' to test this.
class Profile
# Return all profile instances
# For class return use 'ret << i' instead of 'ret << i.all'
def self.all
ret = []
subclasses_of(ActiveRecord::Base).each do |i|
unless i.reflect_on_all_associations.select{|j| j.options[:as] == :profile}.empty?
ret << i
end
end
ret.flatten
end
def self.all_associated
User.all.map{|u| u.profile }.flatten
end
end
Here is my app setup:
User < ActiveRecord::Base
belongs_to :profile, :polymorphic => true
end
Student < ActiveRecord::Base
has_one :user, :as => :profile
end
You should be able to just use the associated collection:
model.assignments.all