An example of using options_for_select with select_tag select_tag 'user_id', options_for_select(@users.collect{ |u| [u.name, u.id] })

This would generate something like: Brad Angie Jenny

In this example, we are editing a collection of region records, each with its own select list of countries. (Region belongs_to :country.) If the region doesn't have a country associated, then we want a default message of "unassigned". Of course, if the region does have a country associated then we want that country displayed:

<% name = "region[" + region.id.to_s + "][country_id]" %> <% id = "region_" + region.id.to_s %>

<%= select_tag(id, options_for_select([["unassigned" , "0" ]] + Country.to_dropdown, region.country_id), {:name => name} ) %> This give us: unassigned England

NB: we're using the handy +acts_as_dropdown+ plugin (http://delynnberry.com/projects/acts-as-dropdown/) but we could just as easily prepare the select list with +map+ / +collect+ as above.

If you want your form to be submitted when user selects something, use:

:onchange => "this.form.submit();"

For example:

select_tag "people", "<option>David</option>", :onchange => "this.form.submit();"

To make sure that you'll receive a array you should declare the name of the select with "[ ]" like that:

==== Example

<%= select_tag "users[]", options_for_select(@users.collect{|x| [x.name,x.id]}), {:multiple => :multiple, :size => 10} %>

An +:onchange+ call can be made using the Rails 3 jquery-ujs helper in the form: select_tag( name, option_tags, misc_html_options, html_5_data-stuff) For example: select_tag( "my_tag_id", get_ids(@entity), class: "progress_and_message", data: { remote: true, url: url_for( action: :my_controller_action, id: my_id) // application symbols progress_bar: "progress_bar_div_id", update: "message_div_id" } ) The jquery_ujs looks for +data-remote+ and +data-url+. These can be spelled out or placed in the data hash. The url must be formed as select_tag does not call url_for, unlike some of the other related tags. Values for application symbols can also be passed through. jQuery triggers will work on the Ajax events that occur. This generates the following:

For example, tying into the events in this case the program makes visible an existing hidden progress bar while awaiting a server response, and then displays a +div+ containing a message returned by the server and hides the progress bar. If the +div+ contains a +class=+ for +notice+ or +error+, then they will fade out.

$(".layout")
.on('ajax:beforeSend', ".progress_and_message", function(){ 
  // get id of element to make visible
  var progress_bar_id = '#' + this.getAttribute('data-progress-bar');
  $(progress_bar_id).show();
})
.on('ajax:complete', ".progress_and_message", function(evt, xhr, options){ 
  // get id of element to contain message and to hide
  var update = this.getAttribute('data-update'); 
  var progress_bar_id = '#' + this.getAttribute('data-progress-bar');
  $("#" + update).replaceWith($(xhr.responseText).attr("id", update));
  $(progress_bar_id).hide();
  // cause responses with these classes to fade away...
  $('.notice').fadeOut(2500);
  $('.error').fadeOut(8000);
});

you need use raw

zshuaibin · Mar 2, 20111 thank

in rails3

select_tag "people", raw("<option>David</option>")

Setting name and id for select_tag

ctagg · May 2, 2009

Sometimes you need to use select_tag instead of select (because you're after more control or need to use optgroups, for example), but still want the id/name conventions that select would give.

In this case, all you need to do is set the first parameter to whatever would be produced by select, and it'll take care of the id and name attribute automatically, and thus ensure the form data is parsed correctly after submission.

For example, if you want to do something like: form_for :comment do |f| f.select :article_id ...

which would give a select tag with id of "comment_article_id" and a name attribute of "comment[article_id]", which be parsed into the params hash of: 'comment' => {'article_id' => ...

you can instead do form_for :comment do |f| select_tag 'comment[article_id]' ...

which will give the same id and name attributes for the select tag and hence the same params hash in the controller

How to perform :onchange ajax call using jQuery (Rails 3)

stevo · Nov 9, 2010

As remote_function no longer exists in Rails 3, here is some handy substitution

<%= select_tag :assignee_id, options_for_select([["A",1],["B",2]]), :onchange => "$.post('#{model_singular_path(id)}', {'_method':'put', 'model_name[model_field]':this.value} );" %>

You can obviously pass more attributes, change method etc.

Showing the select with a value previously known

zhdzmn · Oct 18, 2012

Enter the value in the 'value to check if exist in the list' section and the drop down should have that selected

==== Code example

select_tag "name",
options_for_select(list.collect{ [ text, value] },
          'value to check if exist in the list', 
          {:include_blank => true}

multiple select has a hidden

rogerdpack · Mar 29, 2017

It's unclear if "select_tag" does this but the normal select method also generates a hidden variable if the "multiple" option is set, see http://apidock.com/rails/ActionView/Helpers/FormOptionsHelper/select

Related methods

• Instance methods
• button_tag
• check_box_tag
• email_field_tag
• field_set_tag
• file_field_tag
• form_tag
• hidden_field_tag
• image_submit_tag
• label_tag
• number_field_tag
• password_field_tag
• phone_field_tag
• radio_button_tag
• range_field_tag
• search_field_tag
• select_tag
• submit_tag
• telephone_field_tag
• text_area_tag
• text_field_tag
• url_field_tag
• utf8_enforcer_tag
• Private methods
• extra_tags_for_form
• form_tag_html
• form_tag_in_block
• html_options_for_form
• sanitize_to_id
• token_tag