i18n-patterns

I18n Patterns for Rails 8

Overview

Rails I18n provides internationalization support:

• Translation lookups
• Locale management
• Date/time/currency formatting
• Pluralization rules
• Lazy lookups in views

Quick Start

# config/application.rb
config.i18n.default_locale = :en
config.i18n.available_locales = [:en, :fr, :de]
config.i18n.fallbacks = true

Project Structure

config/locales/
├── en.yml                    # English defaults
├── fr.yml                    # French defaults
├── models/
│   ├── en.yml               # Model translations (EN)
│   └── fr.yml               # Model translations (FR)
├── views/
│   ├── en.yml               # View translations (EN)
│   └── fr.yml               # View translations (FR)
├── mailers/
│   ├── en.yml               # Mailer translations (EN)
│   └── fr.yml               # Mailer translations (FR)
└── components/
    ├── en.yml               # Component translations (EN)
    └── fr.yml               # Component translations (FR)

Locale File Organization

Organize locale files by domain: models/, views/, mailers/, components/.

• Models: activerecord.models, activerecord.attributes, activerecord.errors
• Views: nested under controller name and action (e.g. events.index.title)
• Shared: common.actions, common.messages, common.date.formats
• Components: components.<component_name>.<key>

See locale-files.md for complete YAML examples for models, views, shared keys, and components.

Usage Patterns

Key Principles

• Use lazy lookup in views: t(".title") resolves to "events.index.title"
• Use _html suffix for strings containing HTML markup
• Use I18n.l (localize) for dates, times, and numbers — not I18n.t
• Use I18n.t with full key path in models, services, and presenters
• Pass dynamic values via interpolation: t(".greeting", name: user.name)

In Views

<h1><%= t(".title") %></h1>
<%= link_to t(".new_event"), new_event_path %>
<p><%= t(".welcome", name: current_user.name) %></p>
<p><%= t(".intro_html", link: link_to("here", help_path)) %></p>