Concatenate fields in collection_select

I am filling a collection_select with a list of models references based
on a column named “model_ref”.

<%= collection_select(:assets, :model_id, @models, :id,
:model_ref,:prompt => ‘- Select a model -’) %>

I have two issues :

  1. I would like to concatenate another column next to the model
    reference inside the option value with the description of this model
    I’ve tried :
    <%= collection_select(:assets, :model_id, @models, :id, {:model_ref
    :description}, :prompt => ‘- Select a model -’) %>

    But it doesn’t work, the text_method of collection_select doesn’t seams
    to support two columns.
    Any idea I can do that ?
  2. The “:prompt =>’-Select a model-’” doesn’t work.
    I’ve tried as the rails API suggest
    “options={:prompt => ‘- Select a model -’}”
    Same problem.