plone.app.multilingual 1.2.1

Multilingual Plone UI package, enables maintenance of translations for both Dexterity types and Archetypes

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.. contents::


Introduction
============

Talking about multi-language support in Plone is talk about
Products.LinguaPlone. It has been the *defacto* standard for managing
translations of Archetypes-based content types in Plone through the years.
Somehow its functionality never made its way into the Plone core and today it is
in legacy status. Nowadays, Plone faces the rising of Dexterity content types
and its incoming adoption into the Plone core in the near future (4.3) and
complete the transition to Plone as default content types in Plone 5.

plone.app.multilingual was designed originally to provide Plone a whole
multilingual story. Using ZCA technologies, enables translations to Dexterity
and Archetypes content types as well managed via an unified UI.

This module provides the user interface for managing content translations. It's
the app package of the next generation Plone multilingual engine. It's designed
to work with Dexterity content types and the *old fashioned* Archetypes based
content types as well. It only works with Plone 4.1 and above due to the use of
UUIDs for referencing the translations.

After more than 7 years, a GSOC, redesigns, reimplementations due to deprecated
libraries, two major Plone versions finally we are able to say that
plone.app.multilingual is finally here.

Components
==========

PAM is composed of four packages, two are mandatory:

* plone.app.multilingual (UI)
* plone.multilingual (core)

and two optionals (at least one should be installed):

* plone.multilingualbehavior (enables Dexterity support via a behavior)
* archetypes.multilingual (enables Archetypes support)

Usage
=====

To use this package with both Dexterity and Archetypes based content types you
should add the following line to your *eggs* buildout section::

eggs =
plone.app.multilingual[archetypes, dexterity]

If you need to use this package only with Archetypes based content types you
only need the following line::

eggs =
plone.app.multilingual[archetypes]

While archetypes is default in Plone for now, you can strip ``[archetypes]``.
This may change in future so we recommend adding an appendix as shown above.


Setup
=====

After re-running your buildout and installing the newly available add-ons, you
should go to the *Languages* section of your site's control panel and select
at least two or more languages for your site. You will now be able to create
translations of Plone's default content types, or to link existing content as
translations.

Features
========

These are the most important features PAM provides.

Root Language folders
---------------------

After the setup, PAM will create root folders for each of your site's
languages and put translated content into the appropriate folders. A language
folder implements INavigationRoot, so from the user's point of view, each
language is "jailed" inside its correspondent language folder. There are event
subscribers in place to capture user interaction with content and update the
language in contents accordingly, for example when user moves or copy content
between language folders.


Babel view
----------

An evolution of the LP *translate* view, unified for either Archetypes and
Dexterity content types. It features an already translated content viewer for
the current content being edited via an ajaxified dinamic selector that shows
them on the fly on user request.


Language independent fields
---------------------------

PAM has support for language independent fields, but with a twist respect the
LP implementation. As PAM does design does not give more relevance to one
translated object above the others siblings (has no canonical object), fields
marked as language independent get copied over all the members of the
translation group always. The PAM UI will warn you about this behavior by
reminding you that the values in the field on the other group participants
will be overwritten.


Translation locator policy
--------------------------

When translating content, this policy decides how it would be placed in the
site's structure. There are two policies in place:

* LP way, the translation gets placed in the nearest translated folder in
parent's hierarchy

* Ask user where to place the translated element in the destination
language root folder


Language selector policy
------------------------

While browsing the site, the language selector viewlet allows users to switch
site's content language and ease access between translations of the current
content. There are two policies in place in case the translation of a specific
language does not exist (yet):

* LP way, the selector shows the nearest translated container.
* Shows the user an informative view that shows the current available
translations for the current content.


Neutral root folder support
---------------------------

The root language folders are used to place the tree of the correspondent
language content. However, there are some use cases we need content that does
not belongs to any language. For example, for assets or side resources like
images, videos and documents. There is need to maintain a language neutral
folder for place this kind of objects. After PAM setup, there is a special
folder called *Language shared*. All items placed in this folder will have
neutral as its default language and will be visible from the other root
language folders as they were placed there.


Translation map
---------------

In order to ease the translation tasks, we devised a tool that displays in a
useful way all the current translated objects and its current translation
information. The map also shows a list of missing translations in case you
want to build a *mirrored* (completely) translated site.


Google Translation Service integration
--------------------------------------

If you are subscriber of the Google Translation service (a paid service), you
can setup your API key on *Languages* site setup. Then, you will notice a new
icon in the babel view that takes the original field on the left side and
using Google Translations service, translates its contents and fill the right
side field.


LinguaPlone migration
---------------------

You can migrate your existing LP powered sites to PAM using the *Migration* tab
in the *Languages* control panel. The migration has been divided into 4 steps
for separation of concerns and for improving the success of each of the required
procedures.

Step 0 (optional) - Reindex the language index
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The migration of LinguaPlone content depends on an up-to-date Language index.
Use this step to refresh this index. **Warning:** Depending on the number of
items in your site, this can take a considerable amount of time. This step is
not destructive and can be executed as many times as needed.

Step 1 - Relocate content to the proper root language folder
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This step will move the site's content to its correspondent root language folder
and previously will make a search for misplaced content through the site's
content tree and will move them to its nearest translated parent. **Warning:**
This step is destructive as it will alter your content tree structure. Make sure
you have previously configured your site's languages properly in the 'Site
Languages' tab of the 'Languages' control panel. It's advisable that you do not
perform this step on production servers having not tried it in
development/preproduction servers previously. Depending on the distribution of
your site's content and the accuracy of the language information on each content
object you may need to relocate manually some misplaced content after this step.
Despite the fact that this step is 'destructive' it can be executed as times as
needed if some problem is detected and afterwards you fix the problem. Please,
refer to the procedure log when it finishes.

Step 2 - Transfer multilingual catalog information
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This step will transfer the relations between translations stored by LinguaPlone
to the PAM catalog. This step is not destructive and can be executed as many
times as needed.

Step 3 - Cleanup after migration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This step will search and fix some lost dependencies to the ITranslatable
interface hidden in the relation catalog and it gets rid of them. It must be run
only when LinguaPlone is already uninstalled, so this step is hidden until then.


Marking objects as translatables
================================

Archetypes
----------

By default, if PAM is installed, Archetypes-based content types are marked as
translatables


Dexterity
---------

Users should mark a dexterity content type as translatable by assigning a the
multilingual behavior to the definition of the content type either via file
system, supermodel or through the web.


Marking fields as language independant
======================================

Archetypes
----------

The language independent fields on Archetype-based content are marked the same
way as in LinguaPlone::

atapi.StringField(
'myField',
widget=atapi.StringWidget(
....
),
languageIndependent=True
),

.. note::

If you want to completely remove LinguaPlone of your installation, you
should make sure that your code are dependant in any way of LP.


Dexterity
---------

There are four ways of achieve it.

Grok directive
~~~~~~~~~~~~~~

In your content type class declaration::

from plone.multilingualbehavior import directives
directives.languageindependent('field')

Supermodel
~~~~~~~~~~

In your content type XML file declaration::

<field name="myField" type="zope.schema.TextLine" lingua:independent="true">
<description />
<title>myField</title>
</field>

Native
~~~~~~

In your code::

from plone.multilingualbehavior.interfaces import ILanguageIndependentField
alsoProvides(ISchema['myField'], ILanguageIndependentField)

Through the web
~~~~~~~~~~~~~~~

Via the content type definition in the *Dexterity Content Types* control panel.


Internal design of plone.multilingual
======================================

All the internal features are implemented on the package plone.multilingual.

The key points are:

1. Each translation is a content object
2. There is no canonical object
3. The translation reference storage is external to the content
object
4. Adapt all the steps on translation
5. Language get/set via an unified adapter
6. Translatable marker interface(s)


There is no canonical content object
------------------------------------

Having a canonical object on the content space produces a dependency which is
not orthogonal with the normal behavior of Plone. Content objects should be
autonomous and you should be able to remove it. This is the reason because we
removed the canonical content object. There is a canonical object on the
translation infrastructure but is not on the content space.


Translation reference storage
-----------------------------

In order to maintain the relations between the different language objects we
designed a common object called a *translation group*. This translation group
has an UUID on its own and each object member of the group stores it in the
object catalog register. You can use the ITranslationManager utility to access
and manipulate the members of a translation group given one object of the group.


Adapt all the steps on translation
----------------------------------

The different aspects involved on a translation are adapted, so it's possible
to create different policies for different types, sites, etc.

* ITranslationFactory - General factory used to create a new content

* ITranslationLocator - Where we are going to locate the new translated content

Default : If the parent folder is translated create the content on the
translated parent folder, otherwise create on the parent folder.

* ITranslationCloner - Method to clone the original object to the new one

Default : Nothing

* ITranslationIdChooser - Which id is the translation

Default : The original id + lang code-block

* ILanguageIndependentFieldsManager - Manager for language independent fields

Default: Nothing


Language get/set via an unified adapter
---------------------------------------

In order to access and modify the language of a content type regardless the
type (Archetypes/Dexterity) there is a interface/adapter::

plone.multilingual.interfaces.ILanguage

You can use::

from plone.multilingual.interfaces import ILanguage
language = ILanguage(context).get_language()

or in case you want to set the language of a content::

language = ILanguage(context).set_language('ca')


Translatable marker interface
-----------------------------

In order to know if a content can be translated there is a marker interface:

plone.multilingual.interfaces.ITranslatable


License
=======

GNU General Public License, version 2


Roadmap
=======

This is the planned feature list for PAM:

1.0
---

* Babel view
* Root language folders
* Non invasive language selector
* Universal link
* Language selector policy
* Neutral root folder support
* Catalog based storage
* Translation map
* Google Translation Service integration
* LinguaPlone migration


2.0 (PLIP 13091)
----------------

* The first version compatible with PLIP 13091
(https://dev.plone.org/ticket/13091)
* Update, get rid of legacy code and transfer some of the PAM logic to the
Plone core (plone.app.i18n)
* Perform the same for other parts of Plone core to integrate some monkey
patches and update legacy code from Products.PloneLanguageTool


3.0
---

* XLIFF export/import
* Iterate support: we know there are some needs about iterate integration
* LinguaPlus/linguatools set of useful tools
* Outdated translations alerts and translation workflows support
* plone.app.toolbar/plone.app.cmsui support
* Add support for Deco layouts and content types
* Pluggable translation policies
* Pluggable language policies negotiations


Credits
=======

plone.app.multilingual has been developed based on LinguaPlone by:

Design and development --
Iskra_ (Ramon Navarro Bosch, Victor Fernandez de Alba)

.. _Iskra: http://www.iskra.cat

Additional funding/sponsorship:
Hitotsubashi University in Tokyo, Centre for New European studies
(Jonathan Lewis)

Also many thanks to

Jan-Carel Brand:
For language independent field implementation on AT

Anne Walter:
For pushing for a initial working version

Thomas Massmann, Martijn Pieters, Martin Aspeli, David Glick


Changelog
=========

1.2.1 2013-10-16
----------------

- Solving on-the-fly language independent field
[ramon]

1.2 - 2013-09-24
----------------

- Better testsetup for robot tests using it's own layer.
[saily]

- Revert translation: display of default pages of folders (it doesn't show
content which doesn't have 'is_default_page' attributes).
[bogdangi]

- Add new option to allow users to bypass permission checks when updating
objects with language independent fields.
[saily]

- Add a new alternate languages viewlet, see:
https://support.google.com/webmasters/answer/189077
[saily]

- Remove Twitter-Bootstrap css code from ``multilingual.css`` and set
stylesheet rendering to authenticated users only.
[saily]

- Remove twitter bootstrap styles and make style rendered for authenticated
users only. [saily]

- Add an upgrade step to reimport css_registry
>>>>>>> 6b549354da3186f94eec9f0b597a78db3ed8ac0d
[saily]


1.1 - 2013-06-19
----------------

- Add translation: widget missing
- Translating folder with default_page: menu items added
- Add translation: display of default pages of folders
[ksuess]

- Bugfix: p.a.contentmenu fails if access to translation is not permitted.
Solution: Introduce restricted access and use it in vocabulary for menu.
[jensens]

- Added ++add++ and factory support using session var to store where it comes
from. It maintains the old programatic way so it's possible to create
translations using code.
[ramon]

- Extend travis integration to test against Plone 4.1, 4.2, 4.3 and
include following dependencies into tests:
- ``plone.multilingual``
- ``plone.multilingualbehavior``
- ``archetypes.multilingual``
[saily]

- plone.app.contenttypes compatibility on setup
[sneridagh]

- Added French translation
[bouchardsyl]

- take care to filter out translated contents
wich do no have supported language information
[kiorky]

- added support for language neutral objects with country specific language codes
by checking _combinedlanguagelist too
[agitator]


1.0 - 2013-04-16
----------------

- Remove ITG usage to ITranslationManager usage
[ramon]

- Shared folder working on old collections
[fgrcon]

- Shared folder correct name and reference on setup
[ramon]

- Instead of check for Dexterity, check if p.multilingualbehavior is installed.
If it's installed, then Dexterity is installed too
[sneridagh]

- Fixed travis integration, extend from plone buildout-cache.
[saily]

- Clean the migration template [erral]

- Don't assume a transition called 'publish' will exist [erral]

- Show language name if no native language information is available.
[saily]

- Added Ukrainian translation
[kroman0]

- Add to travis-ci
[saily]

- Use drop-down instead of buttons on babel view if there are more than X
translations [pysailor]


1.0rc1 - 2013-01-26
-------------------

- Improve and finish migration code and related 'Languages' configlet tab
[pysailor, sneridagh]
- Testing of migration code on production sites [pysailor, erralin, sneridagh]
- Fix broken tests and new ones [pysailor, erralin, bloodbare, sneridagh]
- New re-designed language selector and related helper views [erralin,
bloodbare]
- Not translated view improvements [erralin, bloodbare]
- fixed getClosestDestination when translation doesn't exist [gborelli]
- Update deprecated imports to work with Plone 4.3
[saily]


1.0b3 2012-10-04
----------------

- Select the original language in the dexterity babel edit form.
[maurits]

- Add after migration action on view
[do3cc]

- Multilingual Map
[ramon]

- Univeral link
[ramon]

- Catalog patch bug solving
[ramon]

- Language selector bug solving
[sneridagh]

- Babel view javascripts unification and optimization
[ramon]

- Neutral language folder and menu options added
[ramon]

- New tests
[sneridagh]

- Moving templates to templates folder
[ramon]

- Updating language options
[ramon]

- Menu refactoring
[ramon]

- Allow to see all content on adding translation
[ramon]


1.0b2 - 2012-07-08
------------------

- change language index to Language to LinguaPlone coexistance
[ramon]

- don't rebuild the complete catalog on installing
[pbauer]

- add indexes via setuphandler instead of xml to prevents purging on reinstall
[pbauer]

- make babel-view align fields next to each other
[do3cc]

- updated .po files
[gborelli]

- Added rebuild.sh script in order to simplify updating translations
[gborelli]

- Added italian translation
[gborelli]

- Do not fail when the front-page cannot be moved to a new folder
during setup.
[maurits]

- Make it possible to override the portal_type that is used when
creating a root language folder.
[maurits]


1.0b1 - 2012-04-03
------------------

- Added Google Translation Service ajax service [ramon]

- Added babel view on AT [sneridagh]

- Added babel view on dexterity [ramon]

- Added the option to not filter language on folder_contents view
[ramon]

- Added to translation menu to edit a translated language [ramon]

- Initial setup of a site moving content to language folders [ramon]


0.1a2 - 2011-12-04
------------------

- Improved Control Panel [ramon]

- Improved Language Control Panel site languages selector widget to be
more usable.

- Setup the root folder layout for each configured site languages on
languages control panel save settings [ramon, sneridagh]

- Adapt languageselector viewlet from LP [ramon]

- Re-enable and adapt the searchResults patch again [ramon]

- Cleaning description of packages and registerProfile of paml
[sneridagh]


0.1a1 - 2011-10-03
------------------

- Initial version [ramon, awello, sneridagh]