How to have a drop down <select> field in a rails form?
Solution 1:
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 .
Solution 2:
Or for custom options
<%= f.select :desired_attribute, ['option1', 'option2']%>
Solution 3:
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.
Solution 4:
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
Solution 5:
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>