Build Status

Interpret is a rails 3 engine to help you manage your application translations, also allowing you to have editable contents in live. In order to do so it will register the I18n activerecord backend to be used for your application. Interpret is pretty tied to it at the moment, but there are plans to make it backend-agnostic. We believe that key-value stores as I18n backends are pretty awesome and we want to support them, although the activerecord backend with Memoize and Flatten is very fast too, once you have loaded all the data.

Interpret is intented to allow live edition of your contents, making it very easy for your client, your co-workers or yourself to edit them without a deployment.

Caching techniques play a key role here in order to expire the page or the fragment in which a certain content is displayed, and Interpret helps you do this work with an observer, but you are the responsible to expire your caches. See later on caching section.

If you want you can also use Interpret only as a translation tool, like Tolk in which this gem was initially inspired. See later the registered envs section on how to avoid the registration of I18n activerecord backend. This way you can still edit your translations as before, but in this case the modifications you make won't be directly available in your application.



Add the gem to your Gemfile:

gem 'interpret'

Then you must run the interpret setup generator in order to copy some asset files required for the backoffice section, javascripts, css's and a couple of images:

rails g interpret:setup

Finally you should also run this generator to create the 'translations' table required by the I18n active-record backend:

rails g interpret:migration

Development considerations

If you have chosen to have dynamic contents, that is editable text in your website, this means that all this text information is now stored in some database. They no longer belongs to the application itself, they're now seed data, but instead of create it inside seeds.rb you edit an en.yml file or something similar. This is the work flow Interpret expects you to follow, develop your application using the standard .yml locale files and put in there anything you need. Later, after a deployment, run the update rake task to perform a synchronization between the production I18n database and your modifications inside .yml files, not to update the contents but to update the keys.

The tool is different but the concept is the same. The contents you see and edit in development ARE NOT the same contents you will see in production, because they're dynamic and someone else may have changed them. However, the page architecture does belongs to the application, I mean, the actual HTML code you wrote. One <h1>, three paragraphs <p> and a list <ul> with five elements <li>. This markup is there and it expects to have some text in it, translated content, and it have to be there. So, that said, it's clear that you can edit the contents, but not create or remove them.

The Update action

The update action is the core of Interpret. It performs a synchronization between your *.yml files and the I18n backend translations, and it is expected to run after a deployment in order to update your production translations.

  • It will create any translation that exists in .yml files but not in the database backend. When doing so, the value of the translation in yaml files are preserved and copied into the database backend. The same happens if you have created it in more than one language, it is copied for each locale.

  • It will remove any translation that exists in the database backend but not in the .yml files. Note that you can prevent Interpret to remove anything setting the soft option described at the bottom of this document.

  • For any key that exists in both .yml files and database backend it will not do anything.

Main language

The I18n.default_locale configured in your application will be the master language Interpret will use. Keep in mind that rails lets you have a diferent locale key hierarchy for each language in the .yml files, and this behaviour is prohibited in Interpret. Here, the I18n.default_locale is the only language that can be trusted to have all the required and correct locale keys and it will be used to check for inconsitent translations into other languages, knowing what you haven't translated yet.

This is also the locale used when an update action is performed. The synchronization will only check for inconsistent keys between .yml files and database backend within that master language.

Built-in Backoffice

As an Engine, Interpret provides you with a set of backoffice views in order to manage your translations, and to perform some operations with them. You can access it to the following path in your app (unless you define some scope, see later):



This view shows all the translations organized by their keys, in a tree structure as if they were folders and files. If you're used to the typical filesystem architecture it's pretty simple.

Here you can edit your translations using best_in_place, such amazing in-place edition tool by bernat.


Here you have some tools you can use to work with the translations:

  • Export: Clicking the download link you will get a typical rails locale file for the current language. It's generated with ya2yaml so it may be safe to use with utf8.

  • Import: With the upload option you can select a locale file from your computer and it will be used to perform a massive translations update. To be precise, for each translation you have in that file it will either:

    1. Update that translation if it already exists, or
    2. Create that translation if not
  • Update: This action will perform an update from your .yml locale files. It's described in an earlier section of this readme.

  • Dump: Dump the contents of your .yml locale files into I18n backend. All contents will be overwritten, so be cautious!

All of these operations can be very expensive if you have a large number of translations, some optimization work is still required!

You can search by translation key or value, or both of them. The results will be shown in the same way as in Overview, so you can also edit them from there.


To configure Interpret create an initializer file and put in there something like this:

Interpret.configure do |config|
  config.parent_controller = "admin/base_controller"
  # Some other configuration options

The following sections describe in detail all the configuration options available.

Registered environments

Interpret is intended to be used along with I18n active-record backend in order to provide live edition capabilities for your translations. It will automatically register the I18n.backend to the active-record one, with Memoize and Flatten, if the current Rails environment is included in the registered_envs list. By default i's initialized to the following:

Interpret.registered_envs = [:production, :staging]

You can override it in order to activate it also in development:

Interpret.configure do |config|
  config.registered_envs << :development
  # ...

Or to disable it if you only want to use Interpret as a translation tool:

Interpret.configure do |config|
  config.registered_envs = []
  # ...

Adding authorization and custom filters

If you want to add some authorization control over Interpret backoffice, or any custom filters, you can use the Interpret.parent_controller option. This will make all the Interpret controllers to inherit from it, so you can check for user authentication or whatever:

Interpret.configure do |config|
  config.parent_controller = "admin/base_controller"
  # ...

For instance, the above code will make Interpret use Admin::BaseController as a base class for all their controllers, and you can put in there any before_filter you want to check for the current logged in user permissions. It's likely you already have some controller like this to act as a base for all your existing admin or backoffice controllers.

Custom layouts

In order to integrate the Interpret views into your existing backoffice, you can define your own layout to be used by Interpret:

Interpret.configure do |config|
  config.layout = "backoffice"
  # ...

Then Interpret will use the layouts/backoffice.html.<wathever> layout.

If you want further customizations, you can edit the css file Interpret use, it's in public/stylesheets/interpret_style.css. Be aware that this file will be overwritten the next time you run a rails g interpret:setup.

For now there is no generator to copy all the views into your app, but you can do it yourself by-hand if you want to also customize them.

Remember to load the Interpret stylesheet if you use your own layout:

= stylesheet_link_tag "interpret_style"

Routes scope

You can make Interpret build their routes inside a scope of your choice:

Interpret.configure do |config|
  config.scope = "(:locale)"
  # ...

The above code for instance will produce better looking urls inside interpret, as the current locale will be a prefix of the route instead of a GET parameter.


You can allow Interpret to know who is the current logged in user by setting the following:

Interpret.configure do |config|
  config.current_user = "current_user"
  # ...

If the Interpret.current_user option is setted, Interpret will use it in their controllers and views to retrieve the current user, and log their name (or whatever string returned by calling to_s on it) into the log messages every time a translation is modified.


Once you have configured a current_user function, Interpret can work with two different roles. Use the following configuration option:

Interpret.configure do |config|
  config.current_user = "current_user"
  config.admin = "interpret_admin?"
  # ...

In this example, Interpret will call current_user.interpret_admin? to know if the current logged in user is an interpret admin or not. Depending on the result of this call Interpret allow more or less functionalities. If you don't set any admin method, all users will be admins inside Interpret. The same happens if you don't set the current_user option. The following roles are available:


When the result is evaluated to false, the user is considered an editor. This role is for an user who is intended to make translations, but no to administrate the site.

  • It will be able to edit translations.
  • It won't be able to use any of the Tools.
  • It won't be able to modify any protected translation.


When the result is evaluated to true, then the user is considered an admin, so it can:

  • Do everything described in the Built-in Backoffice section.
  • Mark some translations as protected, which means only editable by admins. This can be used to prevent non-technical people to mess up with interpolated translations and things like this.

Live translation edition

This feature will let you edit your translations and contents directly from your application views. This way the edition work is much more user-friendly, since you're changing what your are seeing. To do so, you will need to do two things:

  1. Let Interpret know about who is logged in, setting the current_user option.

  2. Also set an admin option, to discriminate which users are interpret admins.

  3. Use the following helper in your main layout (or all layouts your application use):

    = interpret_live_edition

You should use it at the bottom of your body block.

  1. Set the Interpret.live_edit variable to true, to enable live edition.

From there, if the current logged in user is an admin, he will be able to translate contents in live. Note that this is NOT per user, it's a global setting. Also note that only admins can use it. We know about this limitations and we will improve this functionality in the future for sure.

You also need to take care about caching, obviously this will not work with cached views.


Interpret register the I18n activerecord backend with Flatten and Memoize, so it takes care to reload the I18n backend every time a translation is edited, created or destroyed. Unfortunately I18n only provides a global method .reload! to expire the cache, so we can't be more precise about what exactly translation we want to expire, without patching I18n itself at least.

Besides that, if you're using any kind of caching technique you should use the following:

Interpret.configure do |config|
  config.sweeper = "my_sweeper"
  # ...

Using the above code you tell Interpret to register the MySweeper class as an observer to Interpret::Translation, so you will be able to run expiration logic when a translation changes. With this, you sweeper is the entirely responsible to expire caching, and it's responsible to run an I18n.backend.reload! too, unless you inherit from the given Interpret::ExpirationObserver class.

If you want some help with that, the recommended way to run custom expiration logic is to build your sweeper class like the following:

class MySweeper < Interpret::ExpirationObserver
  def expire_cache(key)
    # run your expiration logic

One parameter will be passed to your expire_cache method, a string containing the key of the affected translation. It's your business to find out which page or fragment you have to expire from here.

Also take note that your sweeper class is in fact an observer, not a Rails sweeper. I've initially implemented this using real sweepers, but I simply don't like the idea to bind the expiration logic to the controllers. And Interpret can't afford it since it needs to expire the cache from a rake task, for example, to run an update after a deployment.

So, you won't be able to use the default expire methods rails provides you, since they are only available from within a controller. You will need to find out a more raw way to expire your cache.

Rake tasks

Interpret comes with two rake tasks, which are simply interfaces to run the same update and dump actions you can run from the Tools section of the backoffice.

rake interpret:update
rake interpret:dump

The update task is what you may want to run after a deployment.

Soft behavior

Using this option you choose between give a full control to Interpret over the I18n translations or not. It defaults to false and you can change it with:

Interpret.configure do |config|
  config.soft = true
  # ...
  • When soft is set to false: Then Interpret is the owner of all I18n translations, in the sense that it hasn't to be worried about creating or deleting translations. This way, if you remove a key from the .yml locale file Interpret will remove that translation from the I18n backend when you run an update.

  • When soft is set to true: Then Interpret will be more cautious with your translations, and won't remove any of them even though if you have removed the key in the .yml file. This is intented to be used when you have a situation where your I18n translations are used by some other means. Initially I've implemented this to make Interpret compatible with Armot, a tool for handle model translations directly with I18n activerecord backend.

In this case, if some translation exists in the I18n backend but not in .yml files, Interpret has no way to know if it's because you have removed them or because it's a translation handled outside Interpret. So, you will end up with unused translations in your database.


Updating, removing or creating a translation will result in a new entry in the log file log/interpret.log. The user who made the modification will be also registered in the log entry, if current_user is available.

This can be used as a sort-of backup system, to restore the old contents of a certain translation. It won't be very difficult to write some script to do this, but by now it's not included in Interpret.

Final notes

Thanks to NodeThirtyThree for their website templates released under CreativeCommons 3.0 license, one of which is used here.

This piece of software is on a very early stage of development, so use it at your own risk!