I have a product display page which is displaying all products on website. Here I want to filter products as per their Owner. As a start, i am displaying owner names on page using each loop:
<% #products.each do |p| %>
<%= link_to p.user.profile.first_name, store_index_path %>
<% end %>
But as owner has multiple products, his name gets displayed multiple times. How to show the name only once?
In simple way you can do like this:
<% #products.map(&:user).uniq.each do |u| %>
<%= link_to u.profile.first_name, store_index_path %>
<% end %>
You can use group_by to create a hash of User => [Products]. Then, you iterate through the unique set of Users, display the information about that owner, and then display each product for that User.
<% products_by_owner = #product.group_by(&:user) %>
<% products_by_owner.keys.each do |user| %>
<%= link_to p.user.profile.first_name, store_index_path %>
<% products_by_owner[user].each do |product| %>
<%= link_to product.name, store_index_path %>
<% end %>
<% end %>
You can use group_by to create a hash with the users as keys and arrays of products as values:
# Eager loading of users will prevent multiple database hits.
# Using find:
#products = Product.find(:all, :include => :user).group_by(&:user)
# using relations:
#products = Product.where(:some_condition => 'etc').includes(:user).group_by(&:user)
In the view:
<% #products.each do |user, user_products| %>
<%= link_to p.user.profile.first_name, store_index_path %>
<% user_products.each do |product| %>
...
<% end %>
<% end %>
Related
I have a Posts Model, and a Projects Model. I want to render both of these on one index page and order them by created_at DESC. How can I do this? Thanks in advance...
Separately?
<% Post.order('created_at DESC').each do |post| %>
#do things
<% end %>
<% Project.order('created_at DESC').each do |project| %>
#do things
<% end %>
Together?
<% (Post.all + Project.all).sort_by{|item| -item.created_at}.each do |item| %>
<% if item.is_a? Post %>
<%= render 'post_partial', post: item %>
<% elsif item.is_a? Project %>
<%= render 'project_partial', project: item %>
<% end %>
<% end %>
Then create a partial for both objects, and use your attributes as needed!
I have an app that has two models Category and Product
Products belong to categories.
I have created a navbar dropdown that requires an #category and #product object to be available across the entire app (the navbar is shown on every page of the application.)
What I can't work out is the best place to put these basic definitions without defining them multiple times in every page definition.
I need to define the following:
#category = Category.all
#products = #category.products.all
The navbar loop will then look something like this.
<% #category.each do |c| %>
<%= c.name %>
<% #products.each do |p| %>
<% link_to product_path(p) do %>
<%= p.name %>
<% end %>
<% end %>
<% end %>
I am a bit of a rails newbie so I am sure there are some errors in here but any help would be much appreciated!
If you need them in every single page of app, you can set them in ApplicationController's before_filter:
class ApplicationController
before_filter :get_categories
# ...
private
def get_categories
#categories = Category.includes(:products)
end
end
then, you can write in your view:
<% #categories.each do |category| %>
<%= category.name %>
<% category.products.each do |product| %>
<%= link_to p.name, p %>
<% end %>
<% end %>
I also fixed some other errors and convention incompatibilities.
The following code is incorrect.
#category = Category.all
#products = #category.products.all
This code assigns to #categories all the categories, then it attempts to fetch the products. It will not work, unless you have defined a products class method in the Category model. But I don't think so, otherwise you will just have to call Product.all.
Moreover, in the code below, you are trying to display the list of products per category, which definitely don't work with the two assignments before. According to what you are trying to achieve, you can't pre-assign the #products, because you want the products for a specific category.
Let's inline everything into the code.
<% Category.all.each do |category| %>
<%= category.name %>
<% category.products.each do |product| %>
<%= link_to product_path(product) do %>
<%= product.name %>
<% end %>
<% end %>
<% end %>
Next step is to make the code a little bit more performant, giving you need it everywhere.
<% Category.select(:id, :name).each do |category| %>
<%= category.name %>
<% category.products.select(:id, :name).each do |product| %>
<%= link_to product_path(product) do %>
<%= product.name %>
<% end %>
<% end %>
<% end %>
You could use pluck, but it will return an array and it will require a little bit more manipulation. However, it's way more performant.
<% Category.pluck(:id, :name).each do |category_id, category_name| %>
<%= category_name %>
<% Product.where(category_id: category_id).pluck(:id, :name).each do |product_id, product_name| %>
<%= link_to product_name, product_path(id: product_id) %>
<% end %>
<% end %>
It's not a good idea to chain all those methods inside a view, let's extract some code into the model.
class Category
def self.simple_listing
order(:name).pluck(:id, :name)
end
end
class Product
def self.simple_category_listing(category_id)
where(category_id: category_id).order(:name).pluck(:id, :name)
end
end
<% Category.simple_listing.each do |category_id, category_name| %>
<%= category_name %>
<% Product.simple_category_listing(category_id).each do |product_id, product_name| %>
<%= link_to product_name, product_path(id: product_id) %>
<% end %>
<% end %>
You can leave all this code into the view, or extract it into a partial. You don't even need to add a controller before filter, or make it "global". The code is self-contained, does not pollute the name space with instance variables, and it can easily be placed whenever you need it.
I created two scaffolds: announce_sections and announcements. The announce_sections are the types of announcements there are (i.e. games, tryouts, etc) and when I create an announcement I specify what type of announce_sections it is. I'm trying to display it so that each announce_section is viewed, with each announcement and its information under the announce_section. This is what I came up with:
<% #announce_sections.each do |announce_section| %>
<%= announce_section.name %>
<% #announcements.each do |announcement| %>
<%= announcement.announcement_title %>
<%= announcement.information %>
<%= announcement.additional_information %>
<%= announcement.type %>
<% end %>
<% end %>
However, this code only displays the announce_sections with the all announcements under it. The announcements don't get separated into their respective announce_sections. How do I change it so that it does?
<% #announce_sections.each do |announce_section| %>
<%= announce_section.name %>
<% #announcements.where(type: announce_section).each do |announcement| %>
<%= announcement.announcement_title %>
<%= announcement.information %>
<%= announcement.additional_information %>
<%= announcement.type %>
<% end %>
<% end %>
Use the name of the field you are using to assign the announcement type instead of 'type'
There are many ways to solve this, but one simple one is to build a hash where the key is the type of announcement_section and the value is an array (or Set) of the announcement. One way to build that hash is to use the Hash.new {|hash, key| ... } form of the constructor.
#hash = Hash.new {|hash, section| hash[section] = Array.new }
#announcements.each do |a|
# for each announcment append it to the array under the hash
#hash[a.section] << a
end
And then, in the view
<% #hash.keys.each do |section| %>
<%= section %>
<% #hash[section].each do |announcement| %>
<%= announcement.announcement_title %>
<%= announcement.information %>
<%= announcement.additional_information %>
<%= announcement.type %>
<% end %>
<% end %>
I have a model Category and a model Weblink. Category has_many Weblink and Weblink belongs_to Category. Now I want to show all categories in a view and within a category all weblinks belonging to that category, something link this:
<ul>
<% #categories.each do |category| %>
<%= category.category_name %>
<% #weblinks.each do |weblink| %>
<%= weblink.category_name link_to weblink.link_name, weblink.link_url %>
<% end %>
<% end %>
In the controller I have:
#categories = Category.all
#weblinks = Weblink.all
This shows every category and within every category all weblinks, instead of just the ones which belong to the specific category. How can I fix this?
Your view code should look like this
<% #categories.each do |category| %>
<%= category.name >
<% category.weblinks.each do |weblink| %>
<%= link_to weblink.name, weblink.link_url %>
<% end -%>
<% end -%>
It your controller, when querying for all the categories you should also include the weblinks model, something like this:
#categories = Category.all(:include => :weblinks)
Scope the inner loop to the outer category using the macro you get with has_many:
<% #categories.each do |category| %>
<%= category.category_name %>
<% category.weblinks.each do |weblink| %>
<%= link_to weblink.link_name, weblink.link_url %>
<% end %>
<% end %>
I need help refactoring this multi-loop thing. Here is what I have:
Campaign has_many Contacts
Campaign also has many Models which are templates: (Email, Call, and Letter).
Because I am looking for overdue on each, I created an array called Event which I'd like to loop through that contains ['email', 'call', 'letter'].
I need a list of all the Emails, Calls and Letters that are "overdue" for every Contact that belongs to a Campaign. Overdue is determined by a from_today method which looks at the date the Contact was entered in the system and the number of days that needs to pass for any given Event. from_today() outputs the number of days from today that the Event should be done for a given Contact.
Here is what I've done, it works for all Emails in a Campaign across all contacts. I was going to try to create another each do loop to change the class names.
Wasn't sure where to begin: named_scope, push some things into a method, etcetera, or -- minimum to be able to dynamically change the class names so at least it loops three times across the different events rather than repeating the code three times:
<% #campaigns.each do |campaign| %>
<h2><%= link_to campaign.name, campaign %></h2>
<% #events.each do |event| %>
<%= event %>
<% for email in campaign.emails %>
<h4><%= link_to email.title, email %> <%= email.days %> days</h4>
<% for contact in campaign.contacts.find(:all, :order => "date_entered ASC" ) %>
<% if (from_today(contact, email.days) < 0) %>
<% if show_status(contact, email) == 'no status'%>
<p> <%= full_name(contact) %>
is <%= from_today(contact,email.days).abs%> days overdue:
<%= do_event(contact, email) %>
</p>
<% end %>
<% end %>
<% end %>
<% end %>
<% end %>
<% end %>
Just to add to Patrick's answer, I would also use the :collection option of render to simplify this a bit further, e.g. have a partial _contact.html.erb to render each contact:
<% if (from_today(contact, email.days) < 0) %>
<% if show_status(contact, email) == 'no status'%>
<p> <%= full_name(contact) %>
is <%= from_today(contact,email.days).abs%> days overdue:
<%= do_event(contact, email) %>
</p>
<% end %>
<% end %>
<% end %>
and then render the contacts collection with
= render :partial => "contact", :collection => #contacts
I also wouldn't do a find in the view, instead I would setup all the variables in the controller, and probably move all the conditional code into a helper. It's preferable to keep as much logic as possible out of the views.
I'd put the output for each resource into a partial, like so:
<% #campaigns.each do |campaign| %>
<h2><%= link_to campaign.name, campaign %></h2>
<%= render 'events', :events => campaign.events %>
<% end %>
then in app/views/campaigns/_events.html.erb
<% events.each do |event| %>
<%= event %>
<%= render 'emails', :emails => event.emails %>
<% end %>
then in app/views/campaigns/_emails.html.erb
<% emails.each do |email| %>
<h4><%= link_to email.title, email %> <%= email.days %> days</h4>
<%= render 'contacts', :contacts => email.contacts.all(:order => "date_entered ASC", :email => email) %>
<% end %>
then in app/views/campaigns/_contacts.html.erb
<% contacts.each do |contact| %>
<% if (from_today(contact, email.days) < 0) %>
<% if show_status(contact, email) == 'no status'%>
<p> <%= full_name(contact) %>
is <%= from_today(contact,email.days).abs%> days overdue:
<%= do_event(contact, email) %>
</p>
<% end %>
<% end %>
<% end %>