How do I use select2-rails with simple_form?-Collection of common programming errors

This select2 jquery library looks awesome. There is a Rails gem but it is very light on the documentation. I would like to generate a simple multiple drop-down menu, using autocomplete. How do I do that?

This is my simple_form_for call:

I have successfully installed the select2-rails gem, but not quite sure how to get it working.

I add this to my home.js.coffeefile:

jQuery ->
    $('#selectWhereToLive').select2()

And am getting this error:

Uncaught query function not defined for Select2 selectWhereToLive 

Thoughts?

Edit 1:

The above simple_form_for call is producing this HTML:

Indicating that the id attribute is being properly set.

Edit 2 – Updated

As @moonfly suggested, I tried adding as: :select to the f.input_field – both with as: :autocomplete included and not included.

The resulting HTML without as: :autocomplete was this:

Yes
No

It pre-populates 2 option values ‘Yes’ and ‘No’. Not quite sure why, but that is what it does.

Update

So I had changed the jquery selector to look for input#ID, and forgot. So I set that back and now it is generating the select box – but it is giving me those 2 Yes & No options. Not quite sure why it is doing that. It’s not returning the values in from my url attribute.

Edit 3

@harish-shetty’s suggestion seems to be working. But now, after it has successfully found the records via autocomplete and using the select2 menu, it is bypassing the setter method I have on my search.rb model.

Basically, what I want to happen is, once the user has finished filling out the form – and I have all the IDs/names for the neighborhoods they want, I want to create a new record in search_neighborhoods for those IDs.

So these are the methods I have:

Search.rb

  def neighborhood_names
    neighborhoods.map(&:name).join(',')
  end

  # we need to put [0] because it returns an array with a single element containing
  # the string of comma separated neighborhoods
  def neighborhood_names=(names)
    names[0].split(',').each do |name|
      next if name.blank?
      if neighborhood = Neighborhood.find_by_name(name)
        search_neighborhoods.build neighborhood_id: neighborhood.id
      end
    end
  end

My SearchController.rb

  def autocomplete_neighborhood_name
    @neighborhood = Neighborhood.select("id, name").where("name LIKE ?", "#{params[:name]}%").order(:name).limit(10)

    respond_to do |format|
      format.json { render json: @neighborhood , :only => [:id, :name] }
    end    
  end

This is what a request looks like right now – which shows that no search_neighborhood records are being created:

Started POST "/searches" for 127.0.0.1 at 2013-03-06 04:09:55 -0500
Processing by SearchesController#create as HTML
  Parameters: {"utf8"=>"?", "authenticity_token"=>"7SeA=", "search"=>{"boro_id"=>"", "neighborhood_names"=>"1416,1394", "property_type_id"=>"", "min_price"=>"", "max_price"=>"", "num_bedrooms"=>"", "num_bathrooms"=>""}}
  Neighborhood Load (0.5ms)  SELECT "neighborhoods".* FROM "neighborhoods" WHERE "neighborhoods"."name" = '1' LIMIT 1
   (0.3ms)  BEGIN
  SQL (0.8ms)  INSERT INTO "searches" ("amenity_id", "boro_id", "created_at", "keywords", "listing_type_id", "max_price", "min_price", "neighborhood_id", "num_bathrooms", "num_bedrooms", "property_type_id", "square_footage", "updated_at") VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13) RETURNING "id"  [["amenity_id", nil], ["boro_id", nil], ["created_at", Wed, 06 Mar 2013 09:09:55 UTC +00:00], ["keywords", nil], ["listing_type_id", nil], ["max_price", nil], ["min_price", nil], ["neighborhood_id", nil], ["num_bathrooms", nil], ["num_bedrooms", nil], ["property_type_id", nil], ["square_footage", nil], ["updated_at", Wed, 06 Mar 2013 09:09:55 UTC +00:00]]
   (32.2ms)  COMMIT
Redirected to http://localhost:3000/searches/29