Fixes #432 - Create association on locale change

[xprazak2]

According to the docs, calling MyPage.instance.header
should get the header text for current locale.
However, the associations are set up in a singleton
for a default locale and never modified.

The language-specific methods like MyPage.instance.header_en
still work, but it would be nice to have fae handle the locale
for us.

This change checks for languages in fae_fields for page
and dynamically changes the association if the locale change
is detected.

[xprazak2]

There is no way I can reasonably satisfy code climate - if I use the guard clause, then I get flagged for the line length.

[johnnyshields]

I would suggest to remove the singleton altogether. Does it really add a substantial performance benefit? The code would be cleaner and more intuitive then.

[xprazak2]

I removed the singleton as suggested.

[xprazak2]

Fixing tests, can't get around the line length/guard clause rules combo.

[jamesmk]

@xprazak2 I'm sorry if the docs weren't clear, but auto-translating attrs is provided by the fae_translate method:

fae/app/models/concerns/fae/base_model_concern.rb

Line 66 in 65a4cb2

def fae_translate(*attributes)

This method is in a concern for user generated models and doesn't currently support Fae::StaticPage.

The @singleton_is_setup is crucial for performance reasons, otherwise all the methods would have to be redefined every time you request an instance. So the meta programming can't change based on I18n.locale.

However, it would be possible to omit the base attr name here and then layer on a dynamic method similar to fae_translate. So Fae::StaticPage would define header_en and header_cs and layed on top would be a dynamic method like:

translated_attributes.each do |attribute|
  define_method attribute.to_s do
    self.send "#{attribute}_#{I18n.locale}"
  end
end

I'm going to close out this and open a ticket. I do like the refactoring you made in the model, so if you want to include that or and attempt at the above, I'll make it a priority.

thanks!

[xprazak2]

Adding fae_translate :field_name to static page as described in #472 works flawlessly, thanks!