LoadError - Expected to define. Rails error when calling module - ruby

I have a module called EntityTrackerHelper. Here is the code:
module EntityTrackerHelper
def self.createUserAction(user_id, type, entity_id)
existingua = UserAction.find(:first, :conditions=> ["user_id = ? and type = ? and entity_id=?", user_id, type, entity_id])
if existingua.nil?
ua = UserAction.new
ua.user_id = user_id
ua.type = type
ua.entity_id = entity_id
ua.date = Time.now
ua.save
else
existingua.date = Time.now
existingua.save
end
end
end
It is used to track changes and user access in an entity.
It is used in a controller as follows.
require "#{Rails.root}/lib/EntityTrackerHelper"
class LessonSectionsController < InheritedResources::Base
def index
user_id = params[:user_id]
lesson_id = params[:lesson_id]
EntityTrackerHelper::createUserAction(user_id, 'LESSON', lesson_id)
lessonSections = LessonSection.find(:all, :conditions => { :lesson_id => params[:lesson_id] })
render :json => {:sections => lessonSections.as_json({:only => [:lesson_id,:id,:name]}), :error => ''}
end
end
I get the following error:
LoadError (Expected /<ProjPath>/<ProjName>/app/models/lesson.rb to define LESSON):
lib/EntityTrackerHelper.rb:12:in `createUserAction'
app/controllers/lesson_sections_controller.rb:9:in `index'
Line 12 in EntityTrackerHelper is UserAction.find...
Any idea?
Thanks

ActiveRecord will use the field type for "single table inheritance". See http://api.rubyonrails.org/classes/ActiveRecord/Base.html (subtitle: single table inheritance).
It means that when it loads the UserAction with type LESSON, ActiveRecord will try to instantiate the class LESSON which is not defined.
You probably should use another name for your type column.

You can try using
**include EntityTrackerHelper**
for more info check this link Call Module function from Controller (NoMethodError)

Related

how to get single latest record from a view and test it in console

I kinda have 2 questions. I have following model and method to get the latest record from view. but when i try to test in console i get error undefined method or variable vCustomerDetails why i am getting the error?
Also, how do i select only one column from view?
SELECT TOP 1 HasConditionFlag FROM vCustomerDetails
WHERE vCustomerDetails.UserID = #user_id
ORDER BY EntryDate DESC
Model
module Customer
class CustomerUsage < ActiveRecord::Base
self.table_name = 'vCustomerDetails'
def self.has_condition_flag(user_id)
vCustomerDetails
.where("vCustomerDetails.UserID = #{user_id}")
.order('vCustomerDetails.EntryDate DESC')
.last
end
end
end
this one worked
def self.has_condition_flag(user_id)
CustomerUsage
.select("vCustomerDetails.HasConditionFlag")
.where("vCustomerDetails.UserID = #{user_id}")
.order('vCustomerDetails.EntryDate DESC')
.first
Remove vCustomerDetails
module Customer
class CustomerUsage < ActiveRecord::Base
self.table_name = 'vCustomerDetails'
def self.has_condition_flag(user_id)
where("vCustomerDetails.UserID = #{user_id}")
.order('vCustomerDetails.EntryDate DESC')
.last
end
end
end
to select a limited number of columns use
.select('HasConditionFlag')

Generating JSON for Sinatra

I'm having an issue with passing the generated JSON notation of my object to my Sinatra application. The problem I have is twofold:
I have 2 classes that are mapped to a database using the Sequel gem. When they generate JSON it is ok and properly implemented.
I have a custom class called registration that maps one of the classes with an additional field. The goal is to generate JSON out of this and pass that JSON to the application using cucumber (test purpose)
The application code responsible for handling the request has the following function defined:
post '/users' do
begin
hash = JSON.parse(self.request.body.read)
registration = Registration.new.from_json(#request.body.read)
registration.user.country = Database::Alaplaya.get_country_by_iso_code(registration.user.country.iso_code)
return 400 unless(registration.is_valid?)
id = Database::Alaplaya.create_user(registration.user)
# If the registration failed in our system, return a page 400.
return 400 if id < 1
end
problem 1: I cannot use the params hash. It exists but is just an empty hash. Why?
problem 2: I cannot deserialize the JSON generated by the class itself. Why?
The registration class looks like this:
require 'json'
class Registration
attr_accessor :user, :project_id
def to_json(*a)
{
'json_class' => self.class.name,
'data' => [#user.to_json(*a), #project_id]
}.to_json(*a)
end
def self.json_create(o)
new(*o['data'])
end
# Creates a new instance of the class using the information provided in the
# hash. If a field is missing in the hash, nil will be assigned to that field
# instead.
def initialize(params = {})
#user = params[:user]
#project_id = params[:project_id]
end
# Returns a string representing the entire Registration.
def inspect
"#{#user.inspect} - #{#user.country.inspect} - #{#project_id}"
end
# Returns a boolean valid representing whether the Registration instance is
# considered valid for the API or not. True if the instance is considered
# valid; otherwise false.
def is_valid?
return false if #user.nil? || #project_id.nil?
return false if !#user.is_a?(User) || !#project_id.is_a?(Fixnum)
return false if !#user.is_valid?
true
end
end
I had to implement the methods to generate the JSON output correctly. When I run this in console I get the following output generated:
irb(main):004:0> r = Registration.new(:user => u, :project_id => 1)
=> new_login - nil - 1
irb(main):005:0> r.to_json
=> "{\"json_class\":\"Registration\",\"data\":[\"{\\\"json_class\\\":\\\"User\\\
",\\\"login\\\":\\\"new_login\\\"}\",1]}"
Which looks like valid JSON to me. However when I POST this to the application server and try to parse this, JSON complains that at least 2 octets are needed and refuses to deserialize the object.
If you're using Sequel as your ORM, try something like this:
In your model:
class Registration < Sequel::Model
many_to_one :user
many_to_one :project
plugin :json_serializer
end
The server:
before do
#data = JSON.parse(request.body.read) rescue {}
end
post '/users' do
#registration = Registration.new #data
if #registration.valid?
#registration.save
#registration.to_json #return a JSON representation of the resource
else
status 422 #proper status code for invalid input
#registration.errors.to_json
end
end
I think you may be overcomplicating your registration process. If the HTTP action is POST /users then why not create a user? Seems like creating a registration is overly complex. Unless your user already exists, in which case POST /users would be incorrect. If what you're really intending to do is add a user to to a project, then you should PUT /projects/:project_id/users/:user_id and the action would look something like this:
class User < Sequel::Model
many_to_many :projects
end
class Project < Sequel::Model
many_to_many :users
end
#make sure your db schema has a table called users_projects or projects_users
put '/projects/:project_id/users/:user_id' do
#find the project
#project = Project.find params[:project_id]
raise Sinatra::NotFound unless #project
#find the user
#user = Project.find params[:project_id]
raise Sinatra::NotFound unless #user
#add user to project's users collection
#project.add_user #user
#send a new representation of the parent resource back to the client
#i like to include the child resources as well
#json might look something like this
#{ 'name' : 'a project name', 'users' : ['/users/:user_id', '/users/:another_user_id'] }
#project.to_json
end

FactoryGirl in Rails - Associations w/ Unique Constraints

This question is an extension to the one raised here:
Using factory_girl in Rails with associations that have unique constraints. Getting duplicate errors
The answer offered has worked perfectly for me. Here's what it looks like:
# Creates a class variable for factories that should be only created once.
module FactoryGirl
class Singleton
##singletons = {}
def self.execute(factory_key)
begin
##singletons[factory_key] = FactoryGirl.create(factory_key)
rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
# already in DB so return nil
end
##singletons[factory_key]
end
end
end
The issue that has come up for me is when I need to manually build an association to support a polymorphic association with a uniqueness constraint in a hook. For example:
class Matchup < ActiveRecord::Base
belongs_to :event
belongs_to :matchupable, :polymorphic => true
validates :event_id, :uniqueness => { :scope => [:matchupable_id, :matchupable_type] }
end
class BaseballMatchup < ActiveRecord::Base
has_one :matchup, :as => :matchupable
end
FactoryGirl.define do
factory :matchup do
event { FactoryGirl::Singleton.execute(:event) }
matchupable { FactoryGirl::Singleton.execute(:baseball_matchup) }
home_team_record '10-5'
away_team_record '9-6'
end
factory :baseball_matchup do
home_pitcher 'Joe Bloe'
home_pitcher_record '21-0'
home_pitcher_era 1.92
home_pitcher_arm 'R'
away_pitcher 'Jack John'
away_pitcher_record '0-21'
away_pitcher_era 9.92
away_pitcher_arm 'R'
after_build do |bm|
bm.matchup = Factory.create(:matchup, :matchupable => bm)
end
end
end
My current singleton implementation doesn't support calling FactoryGirl::Singleton.execute(:matchup, :matchupable => bm), only FactoryGirl::Singleton.execute(:matchup).
How would you recommend modifying the singleton factory to support a call such as FactoryGirl::Singleton.execute(:matchup, :matchupable => bm) OR FactoryGirl::Singleton.execute(:matchup)?
Because right now, the above code will throw uniqueness validation error ("Event is already taken") everytime the hook is run on factory :baseball_matchup. Ultimately, this is what needs to be fixed so that there isn't more than one matchup or baseball_matchup in the DB.
As zetetic has mentioned, you can define a second parameter on your execute function to send the attributes to be used during the call to FactoryGirl.create, with a default value of an empty hash so it didn't override any of them in the case you don't use it (you don't need to check in this particular case if the attributes hash is empty).
Also notice that you don't need to define a begin..end block in this case, because there isn't anything to be done after your rescue, so you can simplify your method by defining the rescue as part of the method definition. The assignation on the case that the initialization was fine will also return the assigned value, so there is no need to explicitly access the hash again to return it. With all these changes, the code will end like:
# Creates a class variable for factories that should be only created once.
module FactoryGirl
class Singleton
##singletons = {}
def self.execute(factory_key, attrs = {})
##singletons[factory_key] = FactoryGirl.create(factory_key, attrs)
rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
# already in DB so return nil
end
end
end
You need to do two things to make this work:
Accept attributes as an argument your execute method.
Key off of both the factory name and the attributes when creating the singleton factories.
Note that step 1 isn't sufficient to solve your problem. Even if you allow execute to accept attributes, the first call to execute(:matchup, attributes) will cache that result and return it any time you execute(:matchup), even if you attempt to pass different attributes to execute. That's why you also need to change what you're using as the hash key for your ##singletons hash.
Here's an implementation I tested out:
module FactoryGirl
class Singleton
##singletons = {}
def self.execute(factory_key, attributes = {})
# form a unique key for this factory and set of attributes
key = [factory_key.to_s, '?', attributes.to_query].join
begin
##singletons[key] = FactoryGirl.create(factory_key, attributes)
rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
# already in DB so return nil
end
##singletons[key]
end
end
end
The key is a string consisting of the factory name and a query string representation of the attributes hash (something like "matchup?event=6&matchupable=2"). I was able to create multiple different matchups with different attributes, but it respected the uniqueness of the event/matchupable combination.
> e = FactoryGirl.create(:event)
> bm = FactoryGirl.create(:baseball_matchup)
> m = FactoryGirl::Singleton.execute(:matchup, :event => e, :matchupable => bm)
> m.id
2
> m = FactoryGirl::Singleton.execute(:matchup, :event => e, :matchupable => bm)
> m.id
2
> f = FactoryGirl.create(:event)
> m = FactoryGirl::Singleton.execute(:matchup, :event => f, :matchupable => bm)
> m.id
3
Let me know if that doesn't work for you.
Ruby methods can have default values for arguments, so define your singleton method with an empty default options hash:
def self.execute(factory_key, options={})
Now you can call it both ways:
FactoryGirl::Singleton.execute(:matchup)
FactoryGirl::Singleton.execute(:matchup, :matchupable => bm)
within the method, test the options argument hash to see if anything hase been passed in:
if options.empty?
# no options specified
else
# options were specified
end

Having 'allocator undefined for Data' when saving with ActiveResource

What I am missing? I am trying to use a rest service for with Active resource, I have the following:
class User < ActiveResource::Base
self.site = "http://localhost:3000/"
self.element_name = "users"
self.format = :json
end
user = User.new(
:name => "Test",
:email => "test.user#domain.com")
p user
if user.save
puts "success: #{user.uuid}"
else
puts "error: #{user.errors.full_messages.to_sentence}"
end
And the following output for the user:
#<User:0x1011a2d20 #prefix_options={}, #attributes={"name"=>"Test", "email"=>"test.user#domain.com"}>
and this error:
/Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1233:in `new': allocator undefined for Data (TypeError)
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1233:in `load'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1219:in `each'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1219:in `load'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1322:in `load_attributes_from_response'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1316:in `create_without_notifications'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1314:in `tap'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1314:in `create_without_notifications'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/observing.rb:11:in `create'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1117:in `save_without_validation'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/validations.rb:87:in `save_without_notifications'
from /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/observing.rb:11:in `save'
from import_rest.rb:22
If I user curl for my rest service it would be like:
curl -v -X POST -H 'Content-Type: application/json' -d '{"name":"test curl", "email":"test#gmail.com"}' http://localhost:3000/users
with the response:
{"email":"test#gmail.com","name":"test curl","admin":false,"uuid":"afb8c98b-562a-4603-bbe4-f8f0816cef0d","creation_limit":5}
There is a built-in type named Data, whose purpose is rather mysterious. You appear to be bumping into it:
$ ruby -e 'Data.new'
-e:1:in `new': allocator undefined for Data (TypeError)
from -e:1
The question is, how did it get there? The last stack frame puts us here. So, it appears Data wandered out of a call to find_or_create_resource_for. The code branch here looks likely:
$ irb
>> class C
>> end
=> nil
>> C.const_get('Data')
=> Data
This leads me to suspect you have an attribute or similar floating around named :data or "data", even though you don't mention one above. Do you? Particularly, it seems we have a JSON response with a sub-hash whose key is "data".
Here's a script that can trigger the error for crafted input, but not from the response you posted:
$ cat ./activeresource-oddity.rb
#!/usr/bin/env ruby
require 'rubygems'
gem 'activeresource', '3.0.10'
require 'active_resource'
class User < ActiveResource::Base
self.site = "http://localhost:3000/"
self.element_name = "users"
self.format = :json
end
USER = User.new :name => "Test", :email => "test.user#domain.com"
def simulate_load_attributes_from_response(response_body)
puts "Loading #{response_body}.."
USER.load User.format.decode(response_body)
end
OK = '{"email":"test#gmail.com","name":"test curl","admin":false,"uuid":"afb8c98b-562a-4603-bbe4-f8f0816cef0d","creation_limit":5}'
BORKED = '{"data":{"email":"test#gmail.com","name":"test curl","admin":false,"uuid":"afb8c98b-562a-4603-bbe4-f8f0816cef0d","creation_limit":5}}'
simulate_load_attributes_from_response OK
simulate_load_attributes_from_response BORKED
produces..
$ ./activeresource-oddity.rb
Loading {"email":"test#gmail.com","name":"test curl","admin":false,"uuid":"afb8c98b-562a-4603-bbe4-f8f0816cef0d","creation_limit":5}..
Loading {"data":{"email":"test#gmail.com","name":"test curl","admin":false,"uuid":"afb8c98b-562a-4603-bbe4-f8f0816cef0d","creation_limit":5}}..
/opt/local/lib/ruby/gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1233:in `new': allocator undefined for Data (TypeError)
from /opt/local/lib/ruby/gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1233:in `load'
from /opt/local/lib/ruby/gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1219:in `each'
from /opt/local/lib/ruby/gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb:1219:in `load'
from ./activeresource-oddity.rb:17:in `simulate_load_attributes_from_response'
from ./activeresource-oddity.rb:24
If I were you, I would open /Library/Ruby/Gems/1.8/gems/activeresource-3.0.10/lib/active_resource/base.rb, find load_attributes_from_response on line 1320 and temporarily change
load(self.class.format.decode(response.body))
to
load(self.class.format.decode(response.body).tap { |decoded| puts "Decoded: #{decoded.inspect}" })
..and reproduce the error again to see what is really coming out of your json decoder.
I just ran into the same error in the latest version of ActiveResource, and I found a solution that does not require monkey-patching the lib: create a Data class in the same namespace as the ActiveResource object. E.g.:
class User < ActiveResource::Base
self.site = "http://localhost:3000/"
self.element_name = "users"
self.format = :json
class Data < ActiveResource::Base; end
end
Fundamentally, the problem has to do with the way ActiveResource chooses the classes for the objects it instantiates from your API response. It will make an instance of something for every hash in your response. For example, it'll want to create User, Data and Pet objects for the following JSON:
{
"name": "Bob",
"email": "bob#example.com",
"data": {"favorite_color": "purple"},
"pets": [{"name": "Puffball", "type": "cat"}]
}
The class lookup mechanism can be found here. Basically, it checks the resource (User) and its ancestors for a constant matching the name of the sub-resource it wants to instantiate (i.e. Data here). The exception is caused by the fact that this lookup finds the top-level Data constant from the Stdlib; you can therefore avoid it by providing a more specific constant in the resource's namespace (User::Data). Making this class inherit from ActiveResource::Base replicates the behaviour you'd get if the constant was not found at all (see here).
Thanks to phs for his analysis - it got me pointed in the right direction.
I had no choice but to hack into ActiveResource to fix this problem because an external service over which I have no control had published an API where all attributes of the response were tucked away inside a top-level :data attribute.
Here's the hack I ended up putting in config/initializers/active_resource.rb to get this working for me using active resource 3.2.8:
class ActiveResource::Base
def load(attributes, remove_root = false)
raise ArgumentError, "expected an attributes Hash, got #{attributes.inspect}" unless attributes.is_a?(Hash)
#prefix_options, attributes = split_options(attributes)
if attributes.keys.size == 1
remove_root = self.class.element_name == attributes.keys.first.to_s
end
# THIS IS THE PATCH
attributes = ActiveResource::Formats.remove_root(attributes) if remove_root
if data = attributes.delete(:data)
attributes.merge!(data)
end
# END PATCH
attributes.each do |key, value|
#attributes[key.to_s] =
case value
when Array
resource = nil
value.map do |attrs|
if attrs.is_a?(Hash)
resource ||= find_or_create_resource_for_collection(key)
resource.new(attrs)
else
attrs.duplicable? ? attrs.dup : attrs
end
end
when Hash
resource = find_or_create_resource_for(key)
resource.new(value)
else
value.duplicable? ? value.dup : value
end
end
self
end
class << self
def find_every(options)
begin
case from = options[:from]
when Symbol
instantiate_collection(get(from, options[:params]))
when String
path = "#{from}#{query_string(options[:params])}"
instantiate_collection(format.decode(connection.get(path, headers).body) || [])
else
prefix_options, query_options = split_options(options[:params])
path = collection_path(prefix_options, query_options)
# THIS IS THE PATCH
body = (format.decode(connection.get(path, headers).body) || [])
body = body['data'] if body['data']
instantiate_collection( body, prefix_options )
# END PATCH
end
rescue ActiveResource::ResourceNotFound
# Swallowing ResourceNotFound exceptions and return nil - as per
# ActiveRecord.
nil
end
end
end
end
I solved this using a monkey-patch approach, that changes "data" to "xdata" before running find_or_create_resource_for (the offending method). This way when the find_or_create_resource_for method runs it won't search for the Data class (which would crash). It searches for the Xdata class instead, which hopefully doesn't exist, and will be created dynamically by the method. This will be a a proper class subclassed from ActiveResource.
Just add a file containig this inside config/initializers
module ActiveResource
class Base
alias_method :_find_or_create_resource_for, :find_or_create_resource_for
def find_or_create_resource_for(name)
name = "xdata" if name.to_s.downcase == "data"
_find_or_create_resource_for(name)
end
end
end

How to use ActiveRecord callbacks to assign field values before save?

I'm wondering how I can use callbacks to assign values to the database fields, which are processed out of a virtual attribute field.Example:
field :houseno, :type => String
field :street, :type => String
attr_accessor :address
My attempt at this seems to be unsuccessful. Here is what I have:
before_validation :assign_fields
def assign_fields
if #address
#houseno = #address.match(/^(\d+-?(\d+)?)\W*(.*)/)[1]
#street = #address.match(/^(\d+-?(\d+)?)\W*(.*)/)[3]
end
end
And I keep getting this error:
undefined method `houseno' for Building:0x0000010488f108
Have you tried:
write_attribute(:houseno) = #address.match(/^(\d+-?(\d+)?)\W*(.*)/)[1]
or
self.houseno = #address.match(/^(\d+-?(\d+)?)\W*(.*)/)[1]

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