These are my thoughts, on how the translation files should be modeled, take into consideration the following postulates:

• Web applications are modeled around their data.
• Web applications data models have the following states.
  • Saved
  • Deleted
  • Updated
  • Empty
  • Created
  • Loading
• CRUD Operations
  • Copy Should be consistent
  • They are plural
  • They are singular
• Forms and table headers can share the same copy.
• All models forms have
  • placeholders
  • hints

In order to have scalable, maintainable and clean translation files we should, model them according to their data models.

This means:

• Every model should have it's name translated in singular and plural,
• Every attribute should have a translation 1 to 1 relationship.

Model names could share the same namespace as attributes, but that could cause conflicts, so we would rather keep them seperate.

Take the following application models:

Model = Ember.Data.Model.extend({
 name: DS.string(),
 age:    DS.number(),
})
Model = Ember.Data.Model.extend({
 surname: DS.date(),
 age:    DS.number(),
})

The resultant translation file would look as follows:

modelNames:{
  patient:{
    one: 'patient'
    other: 'patients
  },
  inventory:{
    one: 'inventory'
    other: 'inventory items'
  }
}
models: {
  patient: {
    labels: {
      default: {
        firstName: 'First Name',
        lastName: 'Last Name'
      },
      edit: {
        firstName: 'Change First Name',
        lastName: 'Change Last Name'
      },
      new: {
        firstName: 'Set your first name',
        lastName: 'Set your Last Name'
      }
     },
     placeholders: {
      firstName: 'Enter your first bame',
      lastName: 'Enter your first last Name'
     },
     hints: {
       firstName: 'This is the name that your parents gave you, unless you changed it',
       lastName: 'this is the name you share with your family, , unless you changed it'
     }
  },
  inventory: {
    labels: {
      default: {
        name: 'Name',
        quantity: 'Quantity'
      },
      edit: {
        quantity: 'How many are there now'
      },
    },
    placeholders: {
      name: 'Name of inventory item',
      quantity: 'Quantity of item'
     },
     hints: {
       name: 'What do you call',
       quantity: 'Go to storage and count :)'
     }
  }
}

Here is an example of crud operation message translations:

en: {
  messages: {
    empty: {
      one: "no {{objects}} were found
    },
    loading: {
      success: {
        one: 'Successfully loaded {{object}}',
        other: 'Successfully loaded {{count}} {{object}}'
      },
      error: {
        one: 'oops, something happend when loading {{object}}',
        other: 'Loading {{count}} {{object}}'
      },
    delete: {
      success: {
        one: '{{object}} Successfully deleted',
        other: '{{count}} {{object}} have been successfully deleted'
      },
      error: {
        one: 'Something went wrong deleting {{object}}',
        other: 'Something went wrong deleting these records {{object}}'
      },
      confirmation: {
        one: 'Are you sure you wish to delete this {{object}}?'
        other: 'Are you sure you wish to delete {{object}}?'
      }
    },
    save: {
      success: {
        one: '{{object}} Successfully saved'
        other: '{{object}} have been Successfully saved'
      },
      error: {
        one: 'Something went wrong saving {{object}}'
        other: 'Something went wrong saving these records {{object}}'
      }
    },
    update: {
      success: {
        one: '{{object}} Successfully updated'
        other: '{{object}} have been Successfully updated'
      },
      error: {
        one: 'Something went wrong updating {{object}}'
        other: 'Something went wrong updating these records {{object}}'
      }
    },
  }
}

Since the translations are now organised, it is easy to generated localised forms, or build helpers for CRUD operation copy

here is an example helper for crud operations

{{translate-message "messages.delete_singular" object=(t "model.lab._one")}}

or a more magical one

{{translate-message "messages.delete" model="lab" count=1}} // displays plural delete
{{translate-message "messages.delete" model="lab" count=2}} // displays plural save

inputs can be wrapped in a {{translated-input}} wrapper

{{translated-input model='invoice' property="price" class="required pricing-override-price"}}