Rails 3: datetime_select with am/pm options

问题:

In Rails 3, is there a way to use datetime_select and display hours showing 12 hour am/pm options rather than 24-hour options?

回答1:

In case anyone stumbles upon this question, the answer for rails 3.2 is:

<%= f.datetime_select :attribute_name,  
                       ampm: true %>  

回答2:

Here's the method I added to my helper class:

def am_pm_hour_select(field_name)
select_tag(field_name,options_for_select([
  ["1 AM", "01"],["2 AM", "02"],["3 AM", "03"],["4 AM", "04"],["5 AM", "05"],["6 AM", "06"],
  ["7 AM", "07"],["8 AM", "08"],["9 AM", "09"],["10 AM", "10"],["11 AM", "11"],["12 PM", "12"],
  ["1 PM", "13"],["2 PM", "14"],["3 PM", "15"],["4 PM", "16"],["5 PM", "17"],["6 PM", "18"],
  ["7 PM", "19"],["8 PM", "20"],["9 PM", "21"],["10 PM", "22"],["11 PM", "23"],["12 AM", "0"]]))
end

Then I plugged that method into my view:

<%= am_pm_hour_select "eventtime[start(4i)]" %>  

It seemed to do the trick, but if there's a more idiomatic way of doing this, I'd be interested to hear.

(update: fixed bugs found by thucydides)

回答3:

The code below treats midnight and noon incorrectly: it calls noon '12 AM,' which is midnight; it calls midnight '12 PM,' which is noon.

Also, the code should use 0:00 as midnight, which is the international standard.

Fixed:

def am_pm_hour_select(field_name)
select_tag(field_name,options_for_select([
    ["1 AM", "01"],["2 AM", "02"],["3 AM", "03"],["4 AM", "04"],["5 AM", "05"],["6 AM", "06"],
    ["7 AM", "07"],["8 AM", "08"],["9 AM", "09"],["10 AM", "10"],["11 AM", "11"],["Noon", "12"],
    ["1 PM", "13"],["2 PM", "14"],["3 PM", "15"],["4 PM", "16"],["5 PM", "17"],["6 PM", "18"],
    ["7 PM", "19"],["8 PM", "20"],["9 PM", "21"],["10 PM", "22"],["11 PM", "23"],["Midnight", "0"]]))
end