How to merge two objects in Ruby on Rails - ruby-on-rails

I'm trying to retrieve from the database two contents: the first one with the field source equal to "imported" (which means that we import it from the excel spreadsheet), and the second one with source != imported (we create it from scratch). Attached is my code:
def index
add_breadcrumb 'Projects', projects_path
add_breadcrumb #project.name, #project
add_breadcrumb "List #{#category.display_name} Content", project_category_contents_path(#project, #category)
#contents_imported = Content.of_project(#project).with_category(#category).imported.order('contents.created_at asc')
#contents_not_imported = Content.of_project(#project).with_category(#category).not_imported.order('contents.created_at desc')
#page = params[:page]
#contents = #contents_not_imported << #contents_imported
#q = #contents.search(params[:q])
#content = #q.result(distinct: true).page(#page).per(20)
end
#contents_imported = Content.of_project(#project).with_category(#category).imported.order('contents.created_at asc')
#contents_not_imported = Content.of_project(#project).with_category(#category).not_imported.order('contents.created_at desc')
And I want to combine the two results before showing it:
#contents = #contents_not_imported << #contents_imported
but it didn't work. How can I do that?

If both of them are arrays and are having same type of objects you can do Result = Arr1 | Arr1
That also removes the duplicates. Its like boolean UNION. In your case #contents = #contents_not_imported | #contents_imported

The problem is that you want to concatenate results, but you also want to continue treating the combined results as an ActiveRelation (call .search on it). Here's a simpler approach that avoids the need for concatenation in the first place. You will need a more complex ORDER BY clause to accomplish this, however:
#page = params[:page]
#contents = Content.of_project(#project).with_category(#category).
order('CASE WHEN source <> "imported" THEN contents.created_at END desc, CASE WHEN source = "imported" THEN contents.created_at END asc')
#q = #contents.search(params[:q])

Concatenating the arrays is done with the plus sign
You are getting undefined method search for Array because, concatenating will return you an array. And you can't call search method on that Array
EDIT
def index
add_breadcrumb 'Projects', projects_path
add_breadcrumb #project.name, #project
add_breadcrumb "List #{#category.display_name} Content", project_category_contents_path(#project, #category)
contents_imported_ids = Content.of_project(#project).with_category(#category).imported.order('contents.created_at asc').map(&:id)
contents_not_imported_ids = Content.of_project(#project).with_category(#category).not_imported.order('contents.created_at desc').map(&:id)
#page = params[:page]
contents_ids = contents_imported_ids + contents_not_imported_ids
contents = Content.where(content_ids)
#contents = content_ids.collect{|id| contents.detect{|c| c.id == id}}
#q = #contents.search(params[:q])
#content = #q.result(distinct: true).page(#page).per(20)
end

Just create a new Relation with the conditions of imported or not imported, after that, order all the records (if order is important to #contents and #content):
def index
add_breadcrumb 'Projects', projects_path
add_breadcrumb #project.name, #project
add_breadcrumb "List #{#category.display_name} Content", project_category_contents_path(#project, #category)
#contents_imported = Content.of_project(#project).with_category(#category).imported.order('contents.created_at asc')
#contents_not_imported = Content.of_project(#project).with_category(#category).not_imported.order('contents.created_at desc')
#page = params[:page]
imported = #contents_imported.where_values.reduce(:and)
not_imported = #contents_not_imported.where_values.reduce(:and)
#contents = Content.where(imported.or(not_ipmorted)).order('CASE contents.imported WHEN true THEN contents.created_at asc ELSE contents.created_at desc END')
#q = #contents.search(params[:q])
#content = #q.result(distinct: true).page(#page).per(20)
end
Now you can call Ransack#search on #contents because it is an ActiveRecord::Relation. I assume that the imported scope take a field contents.imported with value true.
If I wrote this without errors, this must works.

Related

How can I query mulltiple tables and order by date in my view

I have a controller with 2 queries :
def index
#invoices = current_company.invoices.order(billed_at: :desc)
#user_invoices = current_user.invoices.order(billed_at: :desc)
end
in my view I have a table with a if to render the table and sometimes I have both to display,
I have a column date in this table,
How can I sort this table by date ?
Simple Rails way - just connect them and sort:
def index
#invoices = current_company.invoices.order(billed_at: :desc)
#user_invoices = current_user.invoices.order(billed_at: :desc)
#all_invoices = (#invoices + #user_invoices).sort_by {|a| a.created_at}.reverse
end
In your view:
- #all_invoices.each do |invoice|
= invoice.id
So simple!
Alternatively if you want to display either company OR user invoices:
def index
if current_company.present?
#invoices = current_company.invoices.order(billed_at: :desc)
elsif current_user.present?
#user_invoices = current_user.invoices.order(billed_at: :desc)
end
end
You could do a union of the two queries and order that...
def index
invoices = current_company.invoices
user_invoices = current_user.invoices
#all_invoices = Invoice.from("(#{invoices.to_sql} UNION #{user_invoices.to_sql}) AS invoices").order(billed_at: :desc)
end
Then you just iterate through #all_invoices. You could test if the invoice is company or user by an if statement if invoice.company == current_company

undefined method `<<' for #<Answer::ActiveRecord_Relation:0x007fada31c7430>

Hi I create a controller Game to display a Q/A game
And I am blocked with <<, here is the code
def play
lvlup(lvl)
if lvl == 1
set_questions
else
get_questions
end
#answers = Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()")
#answer ||= []
#answers << question.answer
#answers = #answers.shuffle
render 'play'
end
I create an array and I put the related answer in the global answers I want to display 4 Max.
Why does the undefined is here?
Here is the total code
class GamesController < ApplicationController
attr_accessor :lvl
def welcome
end
def congrat
end
def play
lvlup(lvl)
if lvl == 1
set_questions
else
get_questions
end
#answers = Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()")
#answer ||= []
#answers << question.answer
#answers = #answers.shuffle
render 'play'
end
def loose
#question = Question.find(params[:question])
flash.now[:alert] = "Miss..."
render 'loose'
end
def check
#lvl = params[:lvl].to_i
answer_id = params[:id].to_i
question = Question.find(params[:question])
if #lvl == lvlmax
render action: 'congrat' and return
elsif answer_id == question.answer_id
flash.now[:notice] = "Well done !"
play
else answer_id != question.answer_id
loose
end
end
private
def lvlup(value)
#lvl = 1 + value.to_i
end
def lvlmax
#lvlmax = Question.all.count
end
def set_questions
#questionsids = []
Question.all.shuffle.each do |d|
#questionsids << d.id
end
cookies[:questions] = #questionsids
end
def get_questions
#questions = cookies[:questions].split('&')
end
def questions
#questions = cookies[:questions]
end
def question
#question = Question.find(questions[lvl])
end
end
Thank you for your help.
You are trying to append to the #answers result - this is an ActiveRecord relation, you cannot append data to that array.
Add .to_a in the end of your line where you set #answers to allow you to append to the array.
#answers = Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()").to_a
mtrolle's answer might be correct, but I have my doubts as to why ActiveRecord::Relation was not returned as Array by default. (Also as mentioned by BroiStatse in his comment.)
I too noticed the same problem with my local setup however it was attributed to another issue all together. I am sharing this here in case you too happen to use MySQL.
Answer.where.not(id: question.answer_id).limit(2).order("RANDOM()")
returns an ActiveRecord::Relation object. And it translates to following SQL:
SELECT `answers`.* FROM `answers` WHERE (id != ID) ORDER BY RANDOM() LIMIT 2
When I try running the same in MySQL, I get:
ERROR 1305 (42000): FUNCTION database.RANDOM does not exist
Apparently MySQL does not have RANDOM() function, instead it uses RAND().
Converting ActiveRecord query accordingly returned correct Array to me:
Answer.where.not(id: question.answer_id).limit(2).order("RAND()")

Filter controller result based on params

I'm trying to filter the results that are returned from my index view based on optional params. My code is working for the first param, sinceDate. But for the second param, searchQeury, nothing is filtered out.
_controller.rb
def index
since = params[:sinceDate]
query = params[:searchQuery]
#articles = Comfy::Cms::Page.published.all
if since
#articles = #articles.reject{ |a| a[:created_at] < Date.parse(since) }
end
if query
#article = #articles.select{ |a| a[:label].match(/#{query}/i) }
end
end
Is it possible that the problem is a typo?
In the line after "if query", it should be perhaps #articles instead of #article.

How to handle multiple conditions of instance variable assignment

I have the following in my controller that will assign a different collection of results depending on what params are received with an Ajax call. It is messy and i would like to just call a function with all the logic in rather than all this in my index controller
class PublicController < ApplicationController
def index
if params[:literacy_param].present?
#skills = Skill.search(params)
elsif params[:numeracy_param].present?
#skills = Skill.numeracy_default_params
elsif params[:numeracy_number_skills].present?
#skills = Skill.numeracy_number_skills
elsif params[:numeracy_measuring_skills].present?
#skills = Skill.numeracy_measuring_skills
elsif params[:numeracy_data_skills].present?
#skills = Skill.numeracy_data_skills
else
#skills = Skill.default_params
end
end
end
Im just a bit unsure on how to set out my function so that it can read the params that are being sent,
I have come up with this so far
private
def skills(params)
if params[:literacy_param].present?
#skills = Skill.search(params)
elsif params[:numeracy_param].present?
#skills = Skill.numeracy_default_params
elsif params[:numeracy_number_skills].present?
#skills = Skill.numeracy_number_skills
elsif params[:numeracy_measuring_skills].present?
#skills = Skill.numeracy_measuring_skills
elsif params[:numeracy_data_skills].present?
#skills = Skill.numeracy_data_skills
else
#skills = Skill.default_params
end
end
Then in my index action i would do
#skills = skills(params)
would this be an efficient way?
Thanks
You can do this
class PublicController < ApplicationController
def index
skills = ['literacy_param', 'numeracy_param', 'numeracy_number_skills', 'numeracy_measuring_skills', 'numeracy_data_skills']
common_in_params = (skills & params).first
#skills = common_in_params.present? ? (common_in_params.eql?('literacy_param') ? Skill.search(params) : Skill.send(common_in_params)) : Skill.default_params
end
end
You can define skills array in an initializer for resusability
One way of doing it would be this:
def skills(params)
set_of_skills = params.slice(
:numeracy_param,
:numeracy_number_skills,
:numeracy_measuring_skills,
:numeracy_data_skills,
).first
#skills = if params[:literacy_param]
Skill.search(params)
elsif set_of_skills
Skill.public_send(set_of_skills)
else
Skill.default_params
end
end
I would also advise to have this extracted into a lib/ folder, and unit-tested. So that in your controller you could perform the following:
def index
#skills = SkillSearch.new(params).search
end
Two ways I can think of doing this right now:
Wrap the params in a unique key. As in params = { :keyword => :literacy_param }, and then use this unique key to identify the right operation.
In you skill.rb:
def self.filter(params)
if params[:keyword] == :literacy_param
search(params)
elsif available_filters.include?(params[:keyword])
public_send(params[:keyword])
else
default_params
end
end
private
def self.available_filters
%i{numeracy_default_params numeracy_number_skills numeracy_measuring_skills numeracy_data_skills}
end
considering that instead of :numeracy_param, you send :numeracy_default_params in :keyword key. Otherwise you'll have to make another elsif inside filter method.
then in your index method:
def index
#skilles = Skill.filter(params)
end
You create a separate filter class, which is an expandable solution, just in case when you need to go for complex search queries and filtering.
Let's call it SkillSeacrher, inside you app/models/skill_searcher.rb:
class SkillSearcher
attr_reader :keyword
def initialize(keyword)
#keyword = keyword
end
def filter
if keyword == :literacy_param
Skill.search(params)
elsif available_filters.include?(keyword)
Skill.public_send(keyword)
else
Skill.default_params
end
end
private
def self.available_filters
%i{numeracy_default_params numeracy_number_skills numeracy_measuring_skills numeracy_data_skills}
end
end
then in index method:
def index
#skills = SkillSearcher.new(params[:keyword]).filter
end
However, you can do one more change to filter method(depends on your taste):
def filter
if keyword == :literacy_param
Skill.search(params)
else
Skill.public_send(available_filters.include?(keyword) ? keyword : :default_params)
end
end
And, if you have all these methods accepting params as arguments then it'd be much more sleek:
def filter
Skill.public_send(available_filters.include?(keyword) ? keyword : :default_params, params)
end

Rails - Fetch results on the basis of number of params in query string

I am working on an events application where i want to filter events depending on the 3 parameters location or starts_at or ends_at in the query string. There can be any one, two or all the parameters in the query string. In i use if-else statement i need to make 6 cases which will make my code clumsy. Rather i am thinking to implement something this way:
class EventsController < ApplicationController
def index
unless params.empty?
unless params[:location].nil?
#events = Event.where("location = ?", params[:location])
end
unless params[:starts_at].nil?
unless #events.empty?
#events = #events.where("start_date = ?", params[:start_date])
else
#events = Event.where("Date(starts_at) = Date(?)", params[:starts_at])
end
end
unless params[:ends_at].nil?
unless #events.empty?
#events = #events.where("end_date = ?", params[:end_date])
else
#events = Event.where("Date(ends_at) = Date(?)", params[:ends_at])
end
end
end
end
end
But this code doesnt work since where query doen not work on an array. Can someone suggest me some solution for this..
You should be able to pass your params hash directly to where, and it will form the correct SQL based on the keys and values of that hash:
Event.where(params)
An example in the console:
1.9.3p194 :001 > puts Example.where(:location => 'here', :started_at => '2012-08-13').to_sql
SELECT "examples".* FROM "examples" WHERE "examples"."location" = 'here' AND "examples"."started_at" = '2012-08-13'
Try Following
def index
unless params.empty?
where_array, arr = [], []
if params[:location]
where_array << "location = ?"
arr << params[:location]
end
if params[:starts_at]
where_array << "start_date = ?"
arr << params[:starts_at]
end
if params[:ends_at]
where_array << "end_date = ?"
arr << params[:ends_at]
end
#events = arr.blank? ? [] : Event.where([where_array.join(" AND "), *arr])
end
end

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