RoR select_tag default value & options

Question

How can I set a default value using select_tag, and how can I keep the options open on page load?

Answer 1

For options_for_select

<%= select_tag("products_per_page", options_for_select([["20",20],["50",50],["100",100]],params[:per_page].to_i),{:name => "products_per_page"} ) %>

For options from collection for select

<%= select_tag "category","<option value=''>Category</option>" +  options_from_collection_for_select(@store_categories, "id", "name",params[:category].to_i)%>

Note that the selected value which you are specifying must be of type value. i.e. if value is in integer format then selected value parameter should also be integer.

Answer 2

Its already explained, Will try to give an example for achieving the same without options_for_select

let the select list be

select_list = { eligible: 1, ineligible: 0 }

So the following code results in

<%= f.select :to_vote, select_list %>

<select name="to_vote" id="to_vote">
  <option value="1">eligible</option>
  <option value="0">ineligible</option>
</select>

So to make a option selected by default we have to use selected: value.

<%= f.select :to_vote, select_list, selected: select_list.can_vote? ? 1 : 0 %>

if can_vote? returns true it sets selected: 1 then the first value will be selected else second.

select name="driver[bca_aw_eligible]" id="driver_bca_aw_eligible">
  <option value="1">eligible</option>
  <option selected="selected" value="0">ineligible</option>
</select>

if the select options are just a array list instead of hast then the selected will be just the value to be selected for example if

select_list = [ 'eligible', 'ineligible' ]

now the selected will just take

<%= f.select :to_vote, select_list, selected: 'ineligible' %>

Answer 3

Try this:

<%= select_tag(:option, options_for_select([["Option 1",1],["Option 2",2],["Option 3",3]], params[:option] ), class:"select") %>

works great in rails 5.

Answer 4

another option (in case you need to add data attributes or other)

= content_tag(:select) do
  - for a in array
    option data-url=a.url selected=(a.value == true) a.name

Answer 5

If you are using select_tag without any other helper, then you can do it in html:

select_tag "whatever", "<option>VISA</option><option selected=\"selected\">MasterCard</option>"

Or with options_for_select:

select_tag "whatever", options_for_select([ "VISA", "MasterCard" ], "MasterCard")

Or with options_from_collection_for_select:

select_tag [SELECT_FIELD_NAME], options_from_collection_for_select([YOUR_COLLECTION], [NAME_OF_ATTRIBUTE_TO_SEND], [NAME_OF_ATTRIBUTE_SEEN_BY_USER], [DEFAULT_VALUE])

Example:

select_tag "people", options_from_collection_for_select(@people, 'id', 'name', '1')

Examples are from select_tag doc, options_for_select doc and from options_from_collection_for_select doc.