How to have a drop down field in a rails form? Asked Jan 01 '13 at 18:27 Active Nov 25 '22 at 00:29 Viewed 2.1e+01k times 85 0 I am creating a scaffold - rails g scaffold Contact email:string email_provider:string but I want the email provider to be a drop down (with gmail/yahoo/msn as options) and not a text field. How can I do this ? ruby-on-rails ruby-on-rails-3 drop-down-menu input selectlist edited Jul 06 '15 at 17:17 Matt 74,352 26 153 180 asked Jan 01 '13 at 18:27 iCyborg 4,699 15 53 84 9 Answers9 106 You can take a look at the Rails documentation . Anyways , in your form : <%= f.collection_select :provider_id, Provider.order(:name),:id,:name, include_blank: true %> As you can guess , you should predefine email-providers in another model -Provider , to have where to select them from . edited Jan 21 '13 at 13:00 R Milushev answered Jan 01 '13 at 18:39 R Milushev 4,295 3 27 35 so the model will be contact.rb, but where should I put that drop down logic ? sorry for naive question, I am new to RoR development – iCyborg Jan 01 '13 at 19:03 2 Your question is OK . If you take a look at the structure of your `app/views/contacts` , you'll find a file `_form.html.erb` . You can try to place it there . This "partial view" is in charge of both creating and updating actions of the scaffold you've generated. – R Milushev Jan 01 '13 at 19:56 5 recommend moving the order(:name) to a scope (which is a method) in the model. It's not a big deal here but over time you will find that having, what is essentially business logic like this (ordering) on a view template becomes a mess. Move it to the controller, or ideally the model and make a scope available there that you can use. One example - if you end up with three screens or templates that use the dropdown, having the order in the views means 3 X duplication. Having it in the model means it is defined in one place and that's the only place to change it which is good. – Michael Durrant Aug 28 '14 at 17:19 63 Or for custom options <%= f.select :desired_attribute, ['option1', 'option2']%> answered Jul 05 '15 at 02:12 Fdwillis 1,050 9 21 7 <%= f.select :desired_attribute, options_for_select([['opt1'], ['opt2']]) This works for me – Abdullah Aden Oct 09 '15 at 14:38 17 You create the collection in the Contact controller - app/controllers/contacts_controller.erb Adding @providers = Provider.all.by_name to the new, create and edit methods, using a scope for the by_name in the Provider model - app/models/provider.rb - for the ordering by name scope by_name order(:name) Then in the view - app/views/contacts/_form.html.erb - you use <%= f.collection_select :provider_id, @providers, :id, :name, include_blank: true %> For rails forms, I also strongly recommend you look at a form builder like simple_form - https://github.com/plataformatec/simple_form - which will do all the heavy lifting. edited Jan 01 '13 at 21:04 Michael Durrant answered Jan 01 '13 at 19:42 Michael Durrant 93,410 97 333 497 Thanks Michael, I edited the question and have put another code which worked for me, so just wondering what is the difference in using Select and collection_select as mentioned in below answers ? – iCyborg Jan 02 '13 at 05:01 11 This is a long way round, but if you have not yet implemented then you can originally create your models this way. The method below describes altering an existing database. 1) Create a new model for the email providers: $ rails g model provider name 2) This will create your model with a name string and timestamps. It also creates the migration which we need to add to the schema with: $ rake db:migrate 3) Add a migration to add the providers ID into the Contact: $ rails g migration AddProviderRefToContacts provider:references 4) Go over the migration file to check it look OK, and migrate that too: $ rake db:migrate 5) Okay, now we have a provider_id, we no longer need the original email_provider string: $ rails g migration RemoveEmailProviderFromContacts 6) Inside the migration file, add the change which will look something like: class RemoveEmailProviderFromContacts < ActiveRecord::Migration def change remove_column :contacts, :email_provider end end 7) Once that is done, migrate the change: $ rake db:migrate 8) Let's take this moment to update our models: Contact: belongs_to :provider Provider: has_many :contacts 9) Then, we set up the drop down logic in the _form.html.erb partial in the views: <div class="field"> <%= f.label :provider %><br> <%= f.collection_select :provider_id, Provider.all, :id, :name %> </div> 10) Finally, we need to add the provders themselves. One way top do that would be to use the seed file: Provider.destroy_all gmail = Provider.create!(name: "gmail") yahoo = Provider.create!(name: "yahoo") msn = Provider.create!(name: "msn") $ rake db:seed answered Nov 01 '15 at 11:53 phobos 522 5 13 7 <%= f.select :email_provider, ["gmail","yahoo","msn"]%> edited Apr 15 '19 at 21:51 gsumk answered Apr 15 '19 at 21:42 gsumk 809 10 15 7 Rails drop down using has_many association for article and category: has_many :articles belongs_to :category <%= form.select :category_id,Category.all.pluck(:name,:id),{prompt:'select'},{class: "form-control"}%> edited Jun 09 '19 at 20:44 Martijn Pieters 1,048,767 296 4,058 3,343 answered May 24 '19 at 10:32 sivamani 465 7 10 6 Please have a look here Either you can use rails tag Or use plain HTML tags Rails tag <%= select("Contact", "email_provider", Contact::PROVIDERS, {:include_blank => true}) %> *above line of code would become HTML code(HTML Tag), find it below * HTML tag <select name="Contact[email_provider]"> <option></option> <option>yahoo</option> <option>gmail</option> <option>msn</option> </select> edited Jan 02 '13 at 11:06 Raghvendra Parashar answered Jan 01 '13 at 18:33 Raghvendra Parashar 3,883 1 23 36 thanks, I am still confused, I understand the code will go in _form.html.erb but where will that select("Contact",) code go ? – iCyborg Jan 01 '13 at 19:01

Answer 1

In your model,

class Contact
  self.email_providers = %w[Gmail Yahoo MSN]
  validates :email_provider, :inclusion => email_providers
end

In your form,

<%= f.select :email_provider, 
    options_for_select(Contact.email_providers, @contact.email_provider) %>

the second arg of the options_for_select will have any current email_provider selected.

Answer 2

I wanted to display one thing (human readable) but store another (an integer id).

Small example

Here's a small example that helped:

<%= form.select(:attribute_name, {cat: 5, dog: 3} )%>

The {cat: 5, dog: 3} will display "cat" and "dog", but save 5 and 3.

---

Real world example

Here's the actual use case. It displays the names of sellers (that humans can read), but saves the sellers' id (an integer):

<div class="field">
  <%= form.label :seller_id %>
  <%= form.select :seller_id, seller_names_and_ids(), {include_blank: true}, {required: true, class: "form-control"} %>
</div>

And the helper is defined as:

def seller_names_and_ids
  # We want this to produce a hash of keys (the thing to display) and values (the thing to save, 
  # in thise case the seller_id integer)
  sellers = Seller.all
  h = {}
  sellers.each do |seller|
    thing_to_display = seller.name + " (" + seller.id.to_s + ")"
    thing_to_save_in_db = seller.id
    h.store(thing_to_display, thing_to_save_in_db) 
  end
  h
end