Middleman i18n not working - ruby-on-rails

Question

I'm newbie using ruby and middleman, I've created my project and all are working fine, but when I go to /es path I don't get any translation. I've searched for info without any results and tried to move code between folders testing configs and nothing.
My folder structure is:
|locales
|---en.yml
|---es.yml
|source
|es
|---index.html.haml
|layouts
|---layout.html.haml
|partials
|_header.html.haml
|_navigation.html.haml
|---index.html.haml
My YAML files
en.yml
en:
home: 'Home'
es.yml
es:
home: 'Inicio'
My HAML
%nav
= link_to t(:home), '/', class: "#{'active' if current_page.url == '/'}"
= link_to 'Portfolio', '/portfolio', class: "#{'active' if current_page.url == '/portfolio/'}"
= link_to t(:skills), '/skills', class: "#{'active' if current_page.url == '/skills/'}"
= link_to t(:about), '/about', class: "#{'active' if current_page.url == '/about/'}"
= link_to t(:contact), '/contact', class: "#{'active' if current_page.url == '/contact/'}"
My config
config.rb
###
# Page options, layouts, aliases and proxies
###
# Per-page layout changes:
#
# With no layout
page '/*.xml', layout: false
page '/*.json', layout: false
page '/*.txt', layout: false
# With alternative layout
# page "/path/to/file.html", layout: :otherlayout
# Proxy pages (http://middlemanapp.com/basics/dynamic-pages/)
# proxy "/this-page-has-no-template.html", "/template-file.html", locals: {
# which_fake_page: "Rendering a fake page with a local variable" }
# General configuration
set :partials_dir, 'partials'
activate :i18n, :templates_dir => 'partials'
activate :directory_indexes
# Reload the browser automatically whenever files change
configure :development do
activate :livereload
end
###
# Helpers
###
# Methods defined in the helpers block are available in templates
# helpers do
# def some_helper
# "Helping"
# end
# end
# Build-specific configuration
configure :build do
# Minify CSS on build
activate :minify_css
# Minify Javascript on build
activate :minify_javascript
end

Answer 1

I couldn't write a comment, but I think this might be the reason, your es.yml is wrong, since it starts en:
en:
home: 'Inicio'
Shouldn't it be
es:
home: 'Inicio'

Answer 2

I know this question is months old but I just had the same problem, looked all over the web for hours trying to find and answer and managed to fix the issue by adding these parameters after activating i18n:
config.rb
configure :build do
activate :i18n,
:mount_at_root => 'en',
:lang_map => { :'en' => 'en', :'es' => 'es' },
:path => '/'
end
Obviously, if you want "es" to be your default, change mount_at_root.
Hope this helps.

Answer 3

I achieved localized paths with separate URLs for English and Spanish by
adding index.es.html.erb in the root of the source directory
and setting activate :i18n, :path => "/:locale/" in the config.rb
In the browser, my language selector sends users to / or /es:
English
http://website.com/
Spanish
http://website.com/es
Folder structure
|data
|---home.json
|locales
|---en.yml
|---es.yml
|source
|---index.html.erb
|---index.es.html.erb
|---_slide.erb
|---config.rb
config.rb
configure :build do
activate :i18n, :path => "/:locale/"
activate :directory_indexes
...
end
slide.erb
Using t as a shortcut for I18n.t, I dynamically reference the translated value through the data.
<%= link_to t([data.link.text]),
data.link.href,
:id => data.link.id,
:class => 'btn btn-primary btn-lg btn-dark'
%>
home.json
The value of "text" correlates to the key in the .yml files.
{
"slides": [
{
"text": "slides.learnMore",
...
},
...
]
}
en.yml
en:
slides:
learnMore: "LEARN MORE"
...
es.yml
es:
slides:
learnMore: "APRENDE MÁS"
...

Answer 4

Move all your .erb.html that require to be duplicated per language to the folder: /source/localizable as explained in the docs:
https://middlemanapp.com/advanced/localization/#localizable-templates
You can change this folder name using the modifier: templates_dir:
# Look in `source/language_specific` instead
activate :i18n, :templates_dir => "language_specific"