ModalH

This is a plugin for localization & delocalization (parsing localized text representation) of data values (numbers, dates, etc.). It also handles values with units (referred to as ‘measures’)

It lives inside the H (for human) namespace; the localization operation is referred to as H.to or to_h (conversion of a value to a localized text representation for human consumption) and delocalization (parsing) is referred to as H.from or from_h (conversion of a localized text for humans to a data value).

It can be integrated with ModalFields to simplify the declaration of attributes to be localized/delocalized.

Code for date parsing has been borrowed from delocalize.

Localization/delocalization of general data values

In views and controllers the method @to_h@ can be used to localize a value for human consumption and @from_h@ to parse human input into a value: (note that @I18n.locale@ will be use as a default)

puts to_h(3.4, :locale=>:es, :precision=>3)      # => 3,400
puts from_h('3,400', :locale=>:es, :type=>Float) # => 3.4

There are also more type-specific methods @number_to_h@, @number_from_h@, @date_to_h@, @date_from_h@, etc.

In models, or any other place outside views or controller the forms @H.to@ (or @H.to_h@) and @H.from@ (or @H.from_h@) are available with the same functionality:

puts H.to(3.4, :locale=>:es, :precision=>3)      # => 3,400
puts H.from('3,400', :locale=>:es, :type=>Float) # => 3.4

Again, type-specific versions exist @H.number_to@, @H.number_from@, etc.

Data values can be formatted with units with the @magnitude@ variants:

puts  H.magnitude_to(3.233, :units=>'km/h', :precision=>2) # => "3,23 km/h"

User input with optional units can be parsed and converted to de desired units:

puts H.magnitude_from('20 m/s', :units=>'km/h') # => 72.0

Inconsistent units will raise an error.

Localization/delocalization of Model attributes

An attribute @attr@ can be declared to be localized in its model class like so:

number_h :attr, :precision=>3

This can also be handled automatically with ModalFields (see the h/fields.rb documentation).

When an attributes is declared to be localized, a localized representation of it is available as @attr_h@:

puts record.attr_h

For example, in a form we could have:

f.text_field :attr_h

To assign localized text to an attribute @attr_h=@ can be used:

record.attr_h = params[:model][:attr_h]

So, forms will work as usual by simply using the @_h@ variant of the fields that need localization.

When using ModalFields, the desired precision for a localized numeric attribute, if different from that of the database field, can be specified with the @:h_precision@ parameter:

attr :decimal, :precision=>3, :h_precision=>2

An attribute can be declared to have units in its model using this syntax:

units_h :attr, :precision=>3, :units=>'mm'

With ModalFields and using the provided automatic units detection, an attribute simply has to be named with the units name as a suffix (separated by an underscore):

attr_mm :decimal, :precision=>3

In this case, to prevent an attribute with such suffix from having units, a parameter @:units=>nil@ can be passed.

The localized form of an attribute with units, @attr_h@ will include its units as when using @H.magnitude_to@.

A localized attribute with units, when assigned through its @attr_h=@ form will accept units in the localized text and will perform the proper conversion. Inconsistent units will produce a nil value for the attribute and will fail to validate.

TODO

Tests
Document translations used
New attribute types: bank account number, credit card number, NIF, money, …

ModalH

Localization/delocalization of general data values

Localization/delocalization of Model attributes

TODO

Copyright