Format DateTime in Text Box in Rails

Question

Is there an easy way to format the display of a DateTime value in a Rails view?

For example, if I'm doing something like:

<%= text_field :my_object, :start_date %>

and only want to display the Date part of the :start_date (i.e. I want to hide the time part), is there a way to format the :start_date string inside of the view such that it will work for creating new my_object items and updating new my_object items?

Just a clarification:

Doing

<%= text_field 
       :my_object,
       :start_date,
       :value => @my_object.start_date.strftime('%m/%d/%Y') %>

works beautifully when the object already exists (i.e. on item updates), however, when creating a new item, since start_date will initially be nil, the view will throw an error

while evaluating nil.strftime

Solution 1

Some great suggestions here, however in those cases where you really do want your text field date formatted a specific way (say you're integrating with a javascript date picker), and you're dealing with nils, I think simply making a minor tweak to your existing method would do the trick:

:value => (@object.start_date.blank? ? '' : @object.start_date.strftime('%m/%d/%Y'))

Solution 2

I can think of three ways:

1) Creating a new method on the model that would format your date however you need it to be

2) Creating a helper method that would do the same

3) Have you tried doing:

<%= text_field 
   :my_object,
   :start_date,
   :value => @my_object.try(:start_date).try(:strftime,'%m/%d/%Y') %>

Solution 3

If your form is tied to an object, (something like <% form_for(:object) do |f| %>) you should use <%= f.text_field :start_date, :value => f.object.start_date.to_s(:date_format) %>

then you can register your :date_format in config/environment.rb

Not sure why you want to do this, but i hope it's for presentation purposes only.

Solution 4

In my application_helper.rb I put

def nice_date_form(the_date)
   return the_date.strftime('%d-%m-%Y')
end

In any edit.html.erb view file with a jQuery datepicker I then use:

<% if @activity.end_date? %> 
    <%= f.text_field :end_date, :value => nice_date_form(@activity.end_date) %>
<% else %>
    <%= f.text_field :end_date %>
<% end %>

Solution 5

This can be handled DRYly at the model layer using the Rails-provided <attribute>_before_type_cast method variant. Rails already uses this method for doing just this type of formatting, so we're just overwriting the default. For example:

class MyModel
   def start_date_before_type_cast
      return unless self[:start_date]
      self[:start_date].strftime('%m/%d/%Y')
   end
end

This way, anywhere you have a text field for the MyModel#start_date field you get formatting for "free".

View more solutions

Comments

[jerhinesmith]

It's mostly to prevent someone from thinking they need to or should input a time. For most users "2019-09-10 17:00:18" just isn't friendly. I'd much rather just be displaying "09/10/2009" since the time part is completely unnecessary for what I'm doing.

[Eimantas]

then you should use select_date helper instead of plain input

[Alessandra Pereyra]

Agree, if it's for selecting a date, a Calendar or select_date helper are better approaches

[jerhinesmith]

I am using a calendar control, which works great when selecting a date -- you put the cursor in the text box, select the date from the calendar, and see your selection get written to the textbox. However, when going back to the page, the textbox is going to display the datetime from the DB, meaning that it will again have the time in there -- which is confusing. I'd personally rather not use select_date since the usability doesn't seem near as high as the calendar control I'm already using. Does that make sense?

[Paul Schreiber]

this worked for me with one adjustment: :value => (f.object.start_date.to_s(:date_format) unless f.object.start_date.nil?)

[jerhinesmith]

You're missing a closing paren at the end, but otherwise this is what I did at first. I eventually went the route of just initializing the start_date to the current date in the object, so that start_date would never be nil in the first place.

[Thomas Schmidt]

@jerhinesmith You are absolute right. Did not test that properly. I changed the code above to test for nil. You could also do that the way Dave Rapin did it, in a nice one-liner.

[jerhinesmith]

what if you changed nice_date_form to something like return (the_date ? the_date.strftime('%d-%m-%Y') : ''). Then, you should be able to remove the conditional from the view.

[Thomas Schmidt]

@jerhinesmith Sure, or going with Dave Rapin's idea, it would look like this: <%= f.text_field :start_date, :value => (@activity.start_date.blank? ? '' : nice_date_form(@activity.start_date)) %> One liners are great if you can see the logic in them. ;-)

[Ole Henrik Skogstrøm]

Even cleaner: value: ( @object.start_date.strftime('%m/%d/%Y') unless @object.start_date.blank?)

[Dave Rapin]

@OleHenrikSkogstrøm nil is not the same as an empty string (which the datepickers I've used required). Definitely use an unless like that though if it works for you.