Multiple values ​​for collection_select

Question

I am trying to have the following HTML in my form:

<select name="user[language_ids][]"> <option value="">Please select</option> <option value="1" selected="selected">English</option> <option value="2">Spanish</option> </select> <select name="user[language_ids][]"> <option value="">Please select</option> <option value="1" selected="selected">English</option> <option value="2">Spanish</option> </select> 

So that the user can select two languages ​​during registration.

I tried with this:

 <%= f.label :languages %> <%= f.collection_select(:language_ids, Language.all, :id, :name) %> <%= f.collection_select(:language_ids, Language.all, :id, :name) %> 

And also with this:

 <%= f.label :languages %> <%= f.collection_select(:language_ids[], Language.all, :id, :name) %> <%= f.collection_select(:language_ids[], Language.all, :id, :name) %> 

After reviewing the answers, I tried with this:

 <%= collection_select(:user, :language_ids, Language.all, :id, :name, {}, {:name => 'user[language_ids][]' }) %> <%= collection_select(:user, :language_ids, Language.all, :id, :name, {}, {:name => 'user[language_ids][]' }) %> 

But the problem here is that both choices have the same identifier, and also they are not related to the form builder f

Any thoughts on how to do this?

Answer 1

Try

 <%= f.collection_select(:language_ids, Language.all, :id, :name,{}, {:multiple => true}) %> 

Answer 2

You can create a collection of fields using fields_for .
The two options will have the same identifier, but collection_select accepts the optional hhml hash options, where you can set a custom identifier.

 <%= f.fields_for :language_ids do |language| %> <%= language.collection_select(nil, Language.all, :id, :name, {include_blank: "Please select", selected: 1}, {id: :user_language_id_1}) %> <%= language.collection_select(nil, Language.all, :id, :name, {include_blank: "Please select", selected: 1}, {id: :user_language_id_2}) %> <% end %> 

generates the following output:

 <select id="user_language_id_1" name="user[language_ids][]"> <option value="">Please select</option> <option value="1" selected="selected">English</option> <option value="2">Spanish</option> </select> <select id="user_language_id_2" name="user[language_ids][]"> <option value="">Please select</option> <option value="1" selected="selected">English</option> <option value="2">Spanish</option> </select> 

Answer 3

You should do something like this:

 <%= f.label :languages %> <%= f.collection_select(:language_ids, Language.all, :id, :name, {}, {id => "language_1", :name => "user[language_ids][]"}) %> <%= f.collection_select(:language_ids, Language.all, :id, :name, {}, {id => "language_2", :name => "user[language_ids][]"}) %> 

Answer 4

Since you wrote "user [language_ids] []" in the name attribute of your choice, I have to assume that you need a multiple choice block. You must do this:

 f.collection_select (:language_ids, Language.all, :id, :name, {:prompt => true}, {:multiple => true}) 

Not a very well documented feature, of course.

EDIT: Having looked further at your example and some of the answers, I would like to point out a few things:

• In your example, there is a “Please Select” prompt as the first option of the selection field, but then you want English to be selected in both examples. If you want the option to be selected, which is it as well as the first option of the selection window, then why do you have an invitation option? One uses it to make the user choose something.

• In one answer, you wrote that you need multiple selections instead of multiple selections, why you don't want: multiple => true solution. I still recommend that you use it, but perhaps you really have a precedent. Therefore, I would recommend that you use the select_tag helper directly (I don't think you will achieve this with the help of the form helpers):

   select_tag "user[language_ids][]", options_from_collection_for_select(Language.all, "id", "name"), :prompt => true, :id => "user_language_ids" 

  Key

  here, to select mutiple, there must be different identifiers that you will have to pass explicitly, so this will be at your fingertips.

Answer 5

Try the following:

 <%=select_tag "language_ids[]" options_for_select([['Please select','']]+Language.all.map{|ln|[ln.name,ln.id]})%> 

Answer 6

Basically sending 2 (or more) fields with the same attribute does not work because params will be turned into a hash: {language_ids: [1], language_ids: [2]} , and since you have the same key, the latter will override the previous one (s).

 {a: 1, a: 2}[:a] #=> 2 

To work around this problem, you need to create different attributes and then combine them into one. To do this, you will need the facade attributes in your model:

 class Language attr_writer :language_one_id, :language_two_id before_save :gather_languages def gather_languages self.language_ids= [language_one_id, language_two_id] end # for the form to display chosen lang (idem with two) def language_id language_ids.first end end # view/_form =f.select :language_one_id, Language.all.map {|l| [l.name, l.id]} =f.select :language_two_id, Language.all.map {|l| [l.name, l.id]} 

But to be honest, I think you make your life harder by going against conventions here (I would use checkboxes instead).

Answer 7

You can add the second language column to your table, and then make it the same content as the first language column.

Answer 8

You can use fields_for like this:

 <%= form_for @user do |f| %> ... <h2>Languages</h2> <%= fields_for :languages do |lang_form| %> <%= lang_form.collection_select :language_id, Language.all, :id, :name %> <% end %> .. <% end %> 

On your controller in your new or edited method you can do this to accept 2 languages

 2.times { @user.languages.build } 

Answer 9

First of all, you must change your user model:

user.rb

 has_many :languages accepts_nested_attributes_for :languages 

Next model generation:

 $> rails g model language user_id:integer name 

language.rb

 belongs_to :user 

users_controller.rb (possibly in a "new" action)

 2.times do language = @user.language.build end 

_form.html.erb

 <%= form_for @user do |f| %> <%= f.fields_for :languages do |lang| %> <%= lang.label :name, "Name" %><br /> <%= lang.select :name, Language.all.collect {|l| [l.name, l.id]}, prompt: 'Please select' %><br /> <%= end %> <p><%= f.submit "Submit" %></p> <% end %> 

Answer 10

uses gem, cocoon gem

as a model you want to add a field

  <div class="form-group"> <%= f.fields_for :photoproducts do |forms_fields| %> <% render partial: "shared/photoproducts_fields", locals: {f: forms_fields} %> <% end %> <%= link_to_add_association('+ Foto', f, :photoproducts, type: "button", class: "btn btn-primary btn-sm") %> </div> 

(In this example, I have a product template to which I add photos)

and then create a partial in the shared folder at the root of the project.

-

project / shared / _fotoproduto_fields.html.erb

 <div class="nested-fields"> <%= link_to_remove_association('remove photo', f, type: "button", class: "btn btn-danger btn-sm") %> <div class="photoproducts"> <div class="form-group"> <label class="control-label"><%= f.label :name %></label> <%= f.text_field :name, class: "form-control", type: "text" %> </div> <div class="form-group"> <label class="control-label"> photo</label> <%= f.file_field :files, class: "form-control" %><br/><br/> </div> </div> </div> 

this way you get a more dynamic form

do not forget to put the parameters in the controllers for the nested attributes and add the model assembly to the create method.

for example: @ products.photoproducts.build