I have to models:
Father has_many Children
f_name
Child belongs_to Father
c_name
father_id(fk)
In children's index page I want to show c_name and fathers' name
<% #children.each do |child|%>
<%= child.name %>
<% if Father.find(child.father_id) %>
<%= Father.find(child.father_id).f_name %>
<% end %>
<% end %>
I do not think the code is elegant. Maybe I should put them into helper or model, but I do not know how to do that.
Anybody help will be appreciated.
I'm not sure how your controller looks like, but it can be like this.
#children = Child.includes(:father)
in view:
<% #children.each do |child|%>
<%= child.name %>
<%= child.father.try(:name) %>
<% end %>
try does same as <%= child.father.name if child.father %>
If you have your relationships correctly setup in your models then rails will give you some nice helper methods. In this case to find a child's father you can do: child.father. Then of course child.father.name to get the name of the father.
If you're worried that a child does not have a father then you could do something like:
<%= child.father.name if child.father %>
Related
I have a #friend model that has_and_belongs_to_many #interests and vice versa. Each interest has a name:string. How do I show all the interests by their name next to each friend?
I tried
friend.interests.count
which shows the correct number, but for
friend.interests.first
the result is
#<Interest:0x00007f959e103250>
How do I display the name of this interest from the database in a view?
<%= friend.interests.count %>
<%= friend.interests.first %>
You can get the name of the interest, just by accessing the friend.interests.first.name. And for listing all the interests you can iterate and show the name of them.
<% friend.interests.each do |interest| %>
<%= interest.name %>
<% end %>
Just put the attribute after the object:
<%= friend.interests.first.name %>
Hello I am trying to create a form in which Model A has many and belong to itself. I tried using nested_form and no luck yet.
I want to create nested form for just Model A.
Can anyone suggest me correct path ?
Without more details on your models and structure it's hard to help, maybe include some code too?
For nested models you typically do something like this:
<%= form_for #model_a do |model_a_form| %>
<%= model_a_form.text_field :attribute_1 %>
<%= model_a_form.text_field :attribute_2 %>
<%= fields_for :child_models, #model_a.child_models do |child_models_fields| %>
<%= child_models_fields.text_field :attribute_1 %>
<%= child_models_fields.text_field :attribute_2 %>
<% end %>
<%= model_a_form.submit %>
<% end %>
See https://apidock.com/rails/ActionView/Helpers/FormHelper/fields_for for more info.
Here is my structure:
Villa model with a belong_to association with a destination model (destination_id).
User model with a habtm association with destination model.
Today in my index view, I use :
<% current_user.destinations.each do |destination| %>
<% #villas.each do |villa| %>
<% if destination == villa.destination %>
<%= villa.name %>
<%end%>
<%end%>
<%end%>
It's not very clear, so can I make a kind of scope in my villa model to select Villas where destination_id == current_user.destinations ?
Thanks a lot
Why don't you list the children villas from the destination itself?
<% current_user.destinations.each do |destination| %>
<% destination.villas.each do |villa| %>
<%= villa.name %>
<%end%>
<%end%>
If you want to forgo this built-in functionality, or if you're scoping a query further from your #villas relation, here's how you do the scope as per these docs
class Villa < ActiveRecord::Base
# ...
scope :by_destinations, -> (destinations) { where(destination: destinations) }
# alternatively...
def self.by_destinations(destinations)
where(destination: destinations)
end
end
Then refer to it with
<% #villas.by_destinations(current_user.destinations) do |villa| %>
<%= villa.name %>
<%end%>
There is 'FoodType' model which are describes types of food in restaurants. I need to make view for creating a new restaurant, and I need to have list of checkboxes in order to allow user to setup types of food for each restaurant. I want to have something like this:
<% FoodType.all.each do |food_type| %>
...
<div class="row">
<%= f.check_box :food_types[0] %>
</div>
...
<% end %>
I want to have parameters like params[restaurant][food_types][0] = true in order to make some actions after creating. Please, tell me, how can I do it? Thanks in advance.
Presumably you have a join table which joins restaurants and food types? Let's say that you have one called restaurant_food_types (with a model RestaurantFoodType), which has restaurant_id and food_type_id?
You will then have this association in restaurants:
Restaurant < ActiveRecord::Base
has_many :restaurant_food_types
has_many :food_types, :through => :restaurant_food_types
This will give you the method .food_type_ids which you can call on a restaurant to set the joins. It's this method that you should hook into in your form: it expects an array of ids, so you need to set up an array-style parameter (one where the name ends in []) You may need to use check_box_tag rather than .check_box, to access an array-style parameter name: i would do this:
<% form_for #restaurant do |f| %>
<% FoodType.all.each do |food_type| %>
...
<div class="row">
<%= check_box_tag "restaurant[food_type_ids][]", food_type.id, #restaurant.food_type_ids.include?(food_type.id) %><%= food_type.name %>
</div>
...
<% end %>
<%= f.submit "Save" %>
<% end %>
Like i say i'm using a check_box_tag here but there might be a nicer way to hook into the food_type_ids method.
How do i get checkbox values in the form from the database? I want the form to bring the existing sub category name,and when i check the checkbox to select that particular category name and not create a new one.I have tried ryan bate's railscast but was no help to me. The realationship here is Category has_many SubCategories and SubCategory belongs_to Category.Thank you.
<%= form_for #category ,:url=>{:action =>"create"} do |f| %>
<%=f.text_field :category_name %>
<%= f.fields_for :sub_categories do |s| %>
<% #category.sub_categories.each do |sub|%>
<%=s.check_box "name",{},sub.id %> <!--need help here-->
<%end%>
<%end%>
<%=f.submit "submit"%>
<%end%>
Based on the exchange in the comments, it appears that you want to use the checkboxes to assign SubCategory objects to a Category object. If that's the case, you're association should be that a Category has_and_belongs_to_many :sub_categories. Then your form would look something like:
<%= form_for #category ,:url=>{:action =>"create"} do |f| %>
<%=f.text_field :category_name %>
<% SubCategories.each do |sc| %>
<div>
<%= check_box_tag :sub_category_ids, sub_category_id, #category.sub_categories.include?(sc), :name => 'category[sub_category_ids][]' -%>
<%= label_tag :sub_category_ids, sc.name -%>
</div>
<% end -%>
<% end %>
Which will show a category form and then list all of the sub_categories that can be assigned or unassigned by checking the checkboxes.
You will also need a join table "categories_sub_categories" for this new association and logic (likely in your controller) to handle the actual assignment.
example for your category_controller.rb
def create
#category = Category.find(params[:id])
#use the checked sub_category_ids from the form to find and assign the sub_categories.
assigned_sub_categories = SubCategory.find(params[:category][:sub_category_ids]) rescue []
#category.sub_categories = assigned_sub_categories
if #category.save
…
else
…
end
end