How to specify decimal precision in a simple_form number field (Rails)

Question

So I have a decimal field with precision 2 in the database, meant to be used for currency. It works fine unless the last decimal place ends in 0, ie. 799.90. It will instead strip it to 799.9 when it's displayed in the field. I know about number_with_precision, but I haven't been able to use that helper method with the simple_form number field since it only takes a symbol and html options as arguments.

I figured then that I would need to create a custom input to extend simple_form's default number_field, but the syntax doesn't seem to be well documented, so I haven't been able to figure out how I might call number_with_precision in the definition of this custom input.

I essentially want to do what the OP of this question Formtastic number field with decimal precision? wanted with formtastic. Thanks!

Answer 1

If you can do it with formtastic you can usually do it with Simple Form in my experience. Try this:

<%= f.input :sales_price, :input_html => {value: number_with_precision(f.object.sales_price, precision: 2) } %>

If using an input_field, then you don't need the :input_html:

<%= f.input_field :sales_price, value: number_with_precision(f.object.sales_price, precision: 2) %>