Thoughts on Class variable for default truncation

[n-at-han-k]

Adding .truncate(2) after every call to Percentage.new when displaying the information in a table is rather tedious.

What are your thoughts on having an option to set truncation for future calls?
Something like the following would be nice and easy to implement.

Percentage.default_truncation = 2
Percentage.new(Rational(1,3)).to_s
# => 0.33%

When working with rails you could then create an initialiser app/config/initializers/percentage.rb to set this globally.

# app/config/initializers/percentage.rb
Percentage.default_truncation = 2

[timcraft]

I don't think having global options/config is appropriate for this gem.

If you want to standardise on the number of digits throughout your application you can use a helper. For example:

<%= percentage_format @change %>

That's the exact same approach as if you were using another numeric class like BigDecimal or Rational, or some other datatype where you need more than the implicit #to_s can provide (date, time, money etc).

You can also use the Rails helper, although it's more verbose:

<%= number_to_percentage(@change.to_d, precision: 1) %>

Another alternative when you're generating tables would be to use some kind of table abstraction that can format values based on their type.

[n-at-han-k]

Good idea, I like it.