I need a little advice about the join and includes methods.
I display a list of groups in the index view. Each has a modal associated, and, in this modal, I would like to display the requests associated to this group. Normally, I'd use #requests = group.requests, but would like to use join for sending just one request to my database.
Since I'm in the index view, I don't have a #group in my action.
controller:
def index
#groups = current_user.groups
end
view (index):
<% #groups.each do |g| %>
<MODAL>
<% #requests = g.requests %>
<% #requests.each do |r| %>
<%= r.date %>
<% end %>
</MODAL>
<% end %>
I guess I can also use join and include for #groups, but there is already one SQL request, so I'm good with it.
In your controller, add includes like this to preload requests and avoid n+1 queries.
def index
#groups = current_user.groups.includes(:requests)
end
View is fine, but you can also write as:-
<% #groups.each do |g| %>
<MODAL>
<% g.requests.each do |r| %>
<%= r.date %>
<% end %>
</MODAL>
<% end %>
Related
Let say I have a controller Transactions:
#transactions = Transaction.all.group(:type)
#transaction_date_asc = Transaction.all.order(:DATE => :desc).group(:type)
#transaction_date_desc = Transaction.all.order(:DATE => :asc).group(:type)
In my view I need to loop all 3 instances.
Something like this where I want to show newest and oldest amount or discount for each transaction type.
<% #transactions do |transaction|%>
transaction.type.name
<%end%>
<% #transaction_date_asc do |transaction_asc|%>
transaction_asc.amount
<%end%>
<% #transaction_date_desc do |transaction_desc|%>
transaction_desc.amount
<%end%>
<% #transaction_date_asc do |transaction_asc|%>
transaction_asc.discount
<%end%>
<% #transaction_date_desc do |transaction_desc|%>
transaction_desc.discount
<%end%>
How am I supposed to place loops, columns and <%end> in my view?
Someone may come up with a better solution, but from my seat it looks like you need to do a query for each group in your view to get the first date transaction, but on the plus side, you only need one query in the controller for the transactions with the last date.
#transactions = Transaction.group(:type).having('DATE = MAX(DATE)')
In the view...
<% #transactions do |transaction| %>
<% first_transaction = Transaction.where(type: transaction.type).order('transaction_date').first %>
<%= transaction.type.name %>
<%= first_transaction.amount %>
<%= transaction.amount %>
<%= first.transaction.discount %>
<%= transaction.discount %>
<% end %>
However... to keep the logic in the view cleaner you could have an instance method for transaction types that will return the first and last transaction.
class Type << ActiveRecord::Base
def first_transaction
Transaction.where(type: self).order('transaction_date ASC').first
end
def last_transaction
Transaction.where(type: self).order('transaction_date DESC').first
end
end
Then in the controller...
#types = Type.all
then in the view...
<% #types.each do |type| %>
<%= type.name %>
<%= type.first_transaction.try(:amount) %>
<%= type.last_transaction.try(:amount) %>
<%= type.first_transaction.try(:discount) %>
<%= type.last_transaction.try(:discount) %>
<% end %>
The reason I'm suggesting #try is to handle the case of no transactions being present for a specific type.
I am trying to implement search functionality in my rails app where I search and display a particular search result first on my index.html.erb view. At the moment I have a search function working and it returns the particular item on its own on the index page.
Ideally I would like to have this item displayed first and then all the other items to display below.
My code is as follows:
brand.rb
def self.search(query)
where("author like ?", "%#{query}%")
end
brand_controller.rb
def index
if params[:search]
#brand = Brand.search(params[:search]).order("created_at DESC")
else
#brand = Brand.all.order(':date')
end
end
I know the where method returns the value as an array so I could probably use array.first to output this result first but is there an easier way to output my desired view. Thanks!
So turned out to be a pretty simple solution, I blame mondays.
All I had to do was create another variable for my search and iterate that result first, then iterate through the rest of the items.
in my controller
def index
#brand = Brand.order('created_at DESC')
if params[:search]
#brand = Brand.search(params[:search]).order("author DESC")
#other = Brand.search_all(params[:search]).order("author DESC")
else
#brand = Brand.all.order('author DESC')
end
end
In my model
def self.search(query)
where("author like ?", "%#{query}%")
end
def self.search_all(query)
where("author not like ?", "%#{query}%")
end
and finally in my view
<% if #brand.any? %>
<% #brand.in_groups_of(2) do |group| %>
<% group.each do |brand| %>
<% if brand %>
<h4> <%= brand.author %></h4>
<a href="<%=brand_path(brand)%>">
<%=image_tag brand.brand_logo, class: 'img-rounded', :"data-uid" => brand.uid %> </a>
<% end %>
<% end %>
<% end %>
<% end %>
<% if #other %>
<% #other.in_groups_of(2) do |group| %>
<% group.each do |other| %>
<% if other %>
<h4> <%= other.author%></h4>
<a href="<%=brand_path(other)%>">
<%=image_tag other.brand_logo %> </a>
<% end %>
<% end %>
<% end %>
<% end %>
I setup a search on my Products index page with PgSearch and Will-Paginate like this:
ProductsController
def index
#products = Product.text_search(params[:query]).page(params[:page]).per_page(5)
end
Products Model
include PgSearch
pg_search_scope :search,
def self.text_search(query)
if query.present?
search(query)
else
scoped
end
end
Product index page
<%= form_tag products_path, method: :get do %>
<%= text_field_tag :query, params[:query] %>
<%= submit_tag "Search", name: nil %>
<% end %>
<% if #products.blank? %>
No Results
<% else %>
<% #products.each do |product| %>
<%= product.name %>
<% end %>
<% end %>
But the problem I'm having now is that when I go to the Product index page, it shows all of the products when I want it to show nothing until a search is done. If the search is blank, return No Results but when you first hit the page it should show nothing. How would this be done?
You probably want to only run a text_search when a search parameter is present. You can put this logic into the view, the controller, or in the model.
In the view
<% if params[:query].present? %>
<% if #products.blank? %>
No Results
<% else %>
<% #products.each do |product| %>
<%= product.name %>
<% end %>
<% end %>
<% end %>
In the controller
def index
if params[:query].present?
#products = Product.text_search(params[:query]).page(params[:page]).per_page(5)
else
#products = Product.none # NOTE: Rails 4 only
end
end
In the model
# create a new method to encapsulate this search logic then use it in the controller
def self.search(value)
if value.present?
Product.text_search(value)
else
Product.none # NOTE: Rails 4 only
end
end
The old saying goes "fat model, skinny controller" so you might want to opt for the model method which will keep your controller and views simpler.
Put your display logic inside an if statement:
<% if params[:query].present? %>
<% if #products.blank? %>
No Results
<% else %>
<% #products.each do |product| %>
<%= product.name %>
<% end %>
<% end %>
<% end %>
Although I'm not familiar with how pg search works, you could do something like this in your method.
It's a nice refactoring as well as it avoids checking for existence and making decisions on params (code smell)
def self.text_search(query = "")
search(query)
end
As I said, not sure how pg_search works. Maybe when you browse for nothing, it returns all records. If that's the case, you can just have it return an empty array. Something like this would do
def self.text_search(query)
return [] if query.nil?
search(query)
end
How can I fetch records just like below with using Model and controler not view?
Pattern1. With helper
application_helper
def user_link(username)
link_to User.find_by_username(username).user_profile.nickname, show_user_path(username)
end
view
<% #topics.order("updated_at DESC").limit(100).each do |topic| %>
<%= user_link(topic.comment_threads.order("id").last.user.username) if topic.comment_threads.present? %>
<% end %>
Pattern2. Without helper. Just only view
<% #topics.order("updated_at DESC").limit(100).each do |topic| %>
<%= link_to(topic.comment_threads.order("id").last.user.nickname, show_user_path(topic.comment_threads.order("id").last.user.username) ) if topic.comment_threads.present? %>
<% end %>
UPDATE
<% #community.topics.eager.recent.each do |topic| %>
<%= user_link(topic.comment_threads.order("id").last.user.username) if topic.comment_threads.present? %>
<% end %>
SQL code or SQL builders should never ever reach the view layer. This should be in your models. I wouldn't even place queries like this in the controller.
I'd extract the topic SQL builder into a named scope. On top of that, to avoid n+1 queries, I'd create another named scope eager:
# topic.rb
scope :eager, includes(comment_threads: :user)
scope :recent, lambda { |n = 100| order("updated_at DESC").limit(n) }
Then I'd move the comment_threads SQL builder into your comment_threads model:
# comment_thread.rb
def self.last_user_nickname
order("id").last.user.nickname
end
We can now tidy up your views:
<% #topics.eager.recent.each do |topic| %>
<%= user_link(topic.comment_threads.last_user_nickname) if topic.comment_threads.present? %>
<% end %>
Allow me to sell Slim to you (erb alternative):
- #topics.eager.recent.each do |topic|
= user_link(topic.comment_threads.last_user_nickname) if topic.comment_threads.present?
I might have even gone a step further and extracted the user_link into a UserDecorator. See https://github.com/drapergem/draper for details.
Summary
Extract SQL builder for topic into eager and recent scopes under topic
Extract SQL builder for comment_threads into last_user_nickname under comment_thread
Look into extracting user_link into a UserDecorator
Use Slim! :)
How can I show recent added #post and #photos in one list? For example:
post - LAlala (10.10.2011)
photos - [] [] [] [] (1.1.2011)
post - Bbbdsfbs (2.12.2010)
post - Lasdasdf2 (2.10.2009)
#posts = Post.limit(20).order('created_at desc')
#photos = Photo.limit(20).order('created_at desc')
#recent_items = (#posts + #photos).sort_by(&:created_at)
<% #recent_items.each do |item| %>
<% if item.class == "Photo" %>
<%= image_tag item.url %>
<% else %>
<%= item.title %>
<% end %>
<% end %>
Alternatively, use group_by to do it like this:
#recent_items = (#posts + #photos).group_by(&:created_at)
<% #recent_items.each do |date, items| %>
Date: <%= date %>
<% items.each do |item| %>
Show information here.
<% end %>
<% end >
I would move the view logic into a helper if I were you for DRYer code.
It is much better to do this is the database.
I just say this: polymorphism + database views.
Create a database view which contains the columns you need from both Post and Photo, including the column "type" containing a the name of the model (you need it for the polymorphism). Call this view for example "list_items". Then create a model called "ListItem". Then you can use this model like any other, paginate it and whatever you need to do.
ListItem.order("created_at > ?", Date.yesterday).page(params[:page])
And don't forget to configure the polymorphic association
However, all this is much easier to accomplish with the listable gem. Check it out!