Rails: Multiple options into a single string

Question

I'm trying to make so that the user sees a number of options (I'm currently trying with check boxes) as selects multiple items, then turns into a single string joined by commas when the user submits it, ex:

<%= f.check_box :answer %><%= option.description %>
<%= f.check_box :answer %><%= option.description %>
<%= f.check_box :answer %><%= option.description %>

where :answer is an attribute in my Answer model and description is an attribute in my Option model, if multiple options are selected I want them to be saved as a single string like so:

"description1,description2,description3"

in order to save it to a single column in my database, how can I achieve this?

Answer 1

You can create multiple checkboxes adding them the multiple option, this way you can have:

<%= f.check_box :answer, { multiple: true }, 'first', false %>First
<%= f.check_box :answer, { multiple: true }, 'second', false %>Second
<%= f.check_box :answer, { multiple: true }, 'third', false %>Third

Note you'll also need to specify the false option to "can get rid" of all the unwanted values a group of multiple check_boxes generates, something like ["0", "0", "second", "0", "third"], that because of the unchecked default values, so, with the last parameter in your check_box helper, you get just ["second", "third"].

So, now having just an array is easier to join those values before persiting the object into the database, this can be done directly in the controller if you want:

@answer = Answer.new(answer_params)
@answer.answer = params['answer']['answer'].join(',')

Here you get the values from the params['answer'], the form, and specifically the checkboxes you've created, as it's an array you can use join to join them with a comma ,, so you'll get "second,third", and this way you can set the answer attribute for your Answer model with multiple checkboxes.