Rails select helper - Default selected value, how?

Question

Here is a piece of code I'm using now:

<%= f.select :project_id, @project_select %>

How to modify it to make its default value equal to to params[:pid] when page is loaded?

I'm not sure whether you want a default project selected when the page is loaded, if :project_id isn't set, or if you want to return the value of the select in the params hash as :pid. — Tilendor, Mar 08 '09 at 17:32

score 239 · Accepted Answer · edited Jul 03 '12 at 12:58

239

This should do it:

<%= f.select :project_id, @project_select, :selected => params[:pid] %>

edited Jul 03 '12 at 12:58

answered Mar 10 '09 at 06:06

htanata

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without params, `options_for_select` is better way. It is good for any situation, good for form edit too. – Adriano Resende Jun 25 '15 at 13:07
Here is the KEY: LOOK at your function (options_for_select() vs f.select. Remember these are different functions. – FlyingV Jan 29 '16 at 18:17

score 145 · Answer 2 · edited Jul 23 '16 at 04:13

145

Use the right attribute of the current instance (e.g. @work.project_id):

<%= f.select :project_id, options_for_select(..., @work.project_id) %>

edited Jul 23 '16 at 04:13

installero

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answered Mar 12 '10 at 17:10

lynx

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This is the best answer because it works with `select_tag` too. Thanks it really helped me too. – stephenmurdoch Nov 26 '14 at 20:42
11

Also you can try `options_for_select(..., f.object.project_id )` – 18augst Mar 18 '15 at 19:59
Thanks so much! All the other accepted answers don't say how to select via variable. – Mike Belanger Jan 09 '18 at 22:47

score 59 · Answer 3 · answered Jul 23 '11 at 13:06

59

Rails 3.0.9

select options_for_select([value1, value2, value3], default)

answered Jul 23 '11 at 13:06

Cheng

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I couldn't figure this solution out until I noticed your closing bracket around the values array **BEFORE** the comma that separates your default value... I missed this bracket here `value3], default` – BigRon Apr 04 '15 at 16:57
I tried a half dozen answers and passing the default to options_for_select was the only thing that worked for me. – Jason L. Dec 02 '21 at 15:23

score 24 · Answer 4 · answered Jan 26 '12 at 10:27

24

Try this:

    <%= f.select :project_id, @project_select, :selected => f.object.project_id %>

answered Jan 26 '12 at 10:27

gavit

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Using Rails 4, the `params[:pid]` did not work, but your example did. – Eric Wanchic Jul 25 '13 at 20:58
This worked for me as I'm using a partial inside "f.fields_for" Thanks. – Hugo Jul 27 '13 at 11:52

score 11 · Answer 5 · edited Apr 14 '16 at 10:17

11

if params[:pid] is a string, which if it came from a form, it is, you'll probably need to use

params[:pid].to_i

for the correct item to be selected in the select list

edited Apr 14 '16 at 10:17

Adobe

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answered Mar 11 '09 at 06:40

danengle

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This answer helped me pinpoint my issue. My select box is dynamic and pulling a collection from the database. I was trying to populate the default selection by a title, not an id of the item. This answer helped me see that issue, and once I populated my `@project` variable with an id from the database table, instead of a title, this code worked appended onto the back of the `form.select` helper: `selected: @project` Thank you @danengle – Christopher Warrington Jan 27 '18 at 22:17

score 10 · Answer 6 · edited Jul 06 '12 at 09:17

10

I've found solution and I found that I'm pretty unexperienced in RoR.

Inside the controller that manages view described above add this:

@work.project_id = params[:pid] unless params[:pid].nil?

edited Jul 06 '12 at 09:17

Tsagadai

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answered Mar 09 '09 at 11:34

totocaster

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score 7 · Answer 7 · edited Nov 08 '11 at 08:41

7

<%= f.select :project_id, @project_select, :selected => params[:pid] %>

edited Nov 08 '11 at 08:41

chown

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answered Sep 02 '11 at 13:58

jschorr

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score 5 · Answer 8 · answered Oct 17 '16 at 23:33

I couldn't get this to work and found that I needed to add the "selected" html attribute not only to the correct <option> tag but also to the <select> tag. MDN's docs on the selected attribute of the select tag say:

selected - Boolean attribute indicates that a specific option can be initially selected.

That means the code should look like:

f.select :project_id, options_for_select(@project_select, default_val), html: {selected: true}

score 3 · Answer 9 · edited Apr 12 '12 at 21:33

3

<%= f.select :project_id, options_from_collection_for_select(@project_select,) %>

edited Apr 12 '12 at 21:33

Bo Persson

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answered Apr 12 '12 at 21:17

swapnilp

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shiva kumar · Answer 10 · 2016-06-12T17:59:35.727

Its already explained, Will try to give an example

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' %>

score 1 · Answer 11 · answered Dec 17 '19 at 21:03

Mike Bethany's answer above worked to set a default value when a new record was being created and still have the value the user selected show in the edit form. However, I added a model validation and it would not let me submit the form. Here's what worked for me to have a model validation on the field and to show a default value as well as the value the user selected when in edit mode.

  <div class="field">
    <%= f.label :project_id, 'my project id', class: "control-label" %><br>
    <% if @work.new_record? %>
      <%= f.select :project_id, options_for_select([['Yes', true], ['No', false]], true), {}, required: true, class: "form-control" %><br>
    <% else %>
      <%= f.select :project_id, options_for_select([['Yes', true], ['No', false]], @work.project_id), {}, required: true, class: "form-control" %><br>
    <% end %>
  </div>

model validation

  validates :project_id, presence: true

score 0 · Answer 12 · answered Oct 05 '14 at 16:25

0

Alternatively, you could set the :project_id attribute in the controller, since the first argument of f.select pulls that particular attribute.

answered Oct 05 '14 at 16:25

promacuser

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score 0 · Answer 13 · answered Dec 30 '14 at 03:03

If try to print the f object, then you will see that there is f.object that can be probed for getting the selected item (applicable for all rails version > 2.3)

logger.warn("f #{f.object.inspect}")

so, use the following script to get the proper selected option:

:selected => f.object.your_field

score -2 · Answer 14 · answered Mar 08 '09 at 12:43

-2

This should work for you. It just passes {:value => params[:pid] } to the html_options variable.

<%= f.select :project_id, @project_select, {}, {:value => params[:pid] } %>

answered Mar 08 '09 at 12:43

epochwolf

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but it won't select appropriate item in select :S – totocaster Mar 08 '09 at 13:09

Rails select helper - Default selected value, how?

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