Class: Mobility::Translations

Inherits:

Pluggable

Object
Module
Pluggable
Mobility::Translations

show all

Defined in:: lib/mobility/translations.rb

Overview

Module containing translation accessor methods and other methods for accessing translations.

Normally this class will be created by calling translates on the model class, added when extending Mobility, but it can also be used independent of that macro.

Including Translations in a Class

Since Translations is a subclass of Module, including an instance of it is like including a module. Options passed to the initializer are passed to plugins (if those plugins have been enabled).

We can first enable plugins by subclassing ‘Mobility::Translations`, and calling plugins to enable any plugins we want to use. We want reader and writer methods for accessing translations, so we enable those plugins:

class Translations < Mobility::Translations
  plugins do
    reader
    writer
  end
end

Both ‘reader` and `writer` depend on the `backend` plugin, so this is also enabled.

Then create an instance like this:

Translations.new("title", backend: :my_backend)

This will generate an anonymous module that behaves approximately like this:

Module.new do
  # From Mobility::Plugins::Backend module
  #
  def mobility_backends
    # Returns a memoized hash with attribute name keys and backend instance
    # values.  When a key is fetched from the hash, the hash calls
    # +self.class.mobility_backend_class(name)+ (where +name+ is the
    # attribute name) to get the backend class, then instantiate it (passing
    # the model instance and attribute name to its initializer) and return it.
  end

  # From Mobility::Plugins::Reader module
  #
  def title(locale: Mobility.locale)
    mobility_backends[:title].read(locale)
  end

  def title?(locale: Mobility.locale)
    mobility_backends[:title].read(locale).present?
  end

  # From Mobility::Plugins::Writer module
  def title=(value, locale: Mobility.locale)
    mobility_backends[:title].write(locale, value)
  end
end

Including this module into a model class will thus add the backends method and reader and writer methods for accessing translations. Other plugins (e.g. fallbacks, cache) modify the result returned by the backend, by hooking into the included callback method on the module, see Plugin for details.

Setting up the Model Class

Accessor methods alone are of limited use without a hook to actually modify the model class. This hook is provided by the Backend::Setup#setup_model method, which is added to every backend class when it includes the Backend module.

Assuming the backend has defined a setup block by calling setup, this block will be called when Translations is #included in the model class, passed attributes and options defined when the backend was defined on the model class. This allows a backend to do things like (for example) define associations on a model class required by the backend, as happens in the Backends::KeyValue and Backends::Table backends.

Since setup blocks are evaluated on the model class, it is possible that backends can conflict (for example, overwriting previously defined methods). Care should be taken to avoid defining methods on the model class, or where necessary, ensure that names are defined in such a way as to avoid conflicts with other backends.

Class: Mobility::Translations

Overview

Including Translations in a Class

Setting up the Model Class

Instance Attribute Summary

Attributes inherited from Pluggable

Method Summary

Methods inherited from Pluggable

Constructor Details