Example of fetching Hash (key,value) to the simple_form collection.

gistfile1.txt

-- model
some sort of constant hash: 
HASH_NAME = {
 0 => "Choose:",
1 => "On-Campus Recruiting - CSO",·
2 => "CSO Staff Referral",
3 => "Faculty Contact",·
4 => "Career Day",·
5 => "CSO Summer Job Listing",·
6 => "Alumni Contact",·
7 => "Personal Contact",·
8 => "Other"·
}
-- view
<%= f.input :some_field, :collection => Model::HASH_NAME.sort.map {|k,v| [v,k]} %>

This would output nice select with select-value as hash key and select-name as hash value, such as:

<select id="form_application_job_source" class="select required" name="form_application[job_source]">
<option value="0">Choose:</option>
<option value="1">On-Campus Recruiting - CSO</option>
<option value="2">CSO Staff Referral</option>
<option value="3">Faculty Contact</option>
<option value="4">Career Day</option>
<option value="5">CSO Summer Job Listing</option>
<option value="6">Alumni Contact</option>
<option selected="selected" value="7">Personal Contact</option>
<option value="8">Other</option>
</select>

Thanks and +1 for @mahemoff solution

@viola: Thanks for posting this, it is exactly what I was looking for!

@mahemoff: I am unable to get your invert method to work. I get the following error:

undefined method `invert' for [["abc", "ABC"], ["cde", "CDE"]]:Array

Here is my hash:

  KINDS = {
    'abc' => 'ABC',
    'cde' => 'CDE'
  }

Here is the view:

<%= f.input :kind, :collection => ProductComponent::KINDS.sort.invert %>

@mahemoff Actually, I just figured it out. I had to invert then sort. Doing sort first was causing the error.

So: <%= f.input :kind, :collection => ProductComponent::KINDS.invert.sort%>

Perfect! exactly what i was looking for. Thanks!

Appreciate the post. Saved me.

6 months later, still very useful post. Thanks viola and others :).

update for my particular case

Since I needed some translation, only half of my problem was solved. So I ran into this gem https://github.com/brainspec/enumerize and voila. I don't need a collection anymore for my simple_form.

Inspired by this great gist I did the following

MY_LIST = ["Choose:", "On-Campus Recruiting - CSO", "CSO Staff Referral","Faculty Contact", "Career Day", "CSO Summer Job Listing", "Alumni Contact", "Personal Contact", "Other"]
HASH_NAME = Hash[MY_LIST.map.with_index{ |obj, i| [i, obj] }]

This let me manage the list separately and add elements if needed!

I appreciate that!

感謝你！thanks for the tip!

Thank you so much for this!! Saved me a ton of time! :)

Exactly what I needed. Thanks!

wonderful! thank you!

Thanks for this. Very useful!

sort method is no longer needed in ruby >1.9

Hashes enumerate their values in the order that the corresponding keys were inserted.
http://ruby-doc.org/core-1.9.3/Hash.html

Five years later... it has been really helpful. Gracias!

Amazingly helpful. Saved a ton of time. Thank you!

f.input :some_field, :collection => Model::HASH_NAME, value_method: :first, label_method: :last

6 years later! Thank you so much!

Again. Thanks! Exactly what I needed today.

Thanks! - Helped me troubleshoot getting my MDB select working properly:
"

<%= options_for_select(Customer::PROVINCES.map {|k,v| [v,k]}) %>

"

Still a relevant and very useful thread, thanks all.