This module allows you to easily cache all responses from the backend - thus speeding up the I18n aspects of your application quite a bit.
To enable caching you can simply include the Cache module to the Simple backend - or whatever other backend you are using:
I18n::Backend::Simple.send(:include, I18n::Backend::Cache)
You will also need to set a cache store implementation that you want to use:
I18n.cache_store = ActiveSupport::Cache.lookup_store(:memory_store)
You can use any cache implementation you want that provides the same API as ActiveSupport::Cache (only the methods fetch and write are being used).
The cache_key implementation assumes that you only pass values to I18n.translate that return a valid key from hash (see www.ruby-doc.org/core/classes/Object.html#M000337).
If you use a lambda as a default value in your translation like this:
I18n.t(:"date.order", :default => lambda {[:month, :day, :year]})
Then you will always have a cache miss, because each time this method is called the lambda will have a different hash value. If you know the result of the lambda is a constant as in the example above, then to cache this you can make the lambda a constant, like this:
DEFAULT_DATE_ORDER = lambda {[:month, :day, :year]} ... I18n.t(:"date.order", :default => DEFAULT_DATE_ORDER)
If the lambda may result in different values for each call then consider also using the Memoize backend.