LOCALIZATION

The EZID UI supports hostname-based customization, or "localization."
Under localization, there are multiple versions of certain components
(templates and static files), and the version used or returned is
determined by the hostname in the request URL, or more specifically,
the HTTP Host header.  Localization can be used to create branded
instances of EZID that sport different logos, text, and contact email
addresses.

Localizations are defined by the LOCALIZATIONS variable declared
primarily in settings/common.py and modified or augmented by the
settings modules corresponding to the different deployment levels.
The variable has the structure:

   LOCALIZATIONS = { hostname: (key, [email_address, ...]), ... }

There must be an entry for the fictitious hostname "default", which,
as its name suggests, serves as a default in case a Host header is
received that doesn't match any entry, or if there is no Host header
at all.  An entry's key field is used to select localized components
as described below.  The email addresses are the help contacts for
that localization.

Components subject to localization reside in .../localized/{key}/
directories.  For example, if the template file logo.html nominally
resides in templates/includes/, and if there are two localizations
with keys "cdl" and "purdue", then there are two versions of logo.html
at templates/includes/localized/cdl/logo.html and
templates/includes/localized/purdue/logo.html.

Within templates, localized components are referenced using the custom
"host_based_include" tag, which has the usage:

   {% host_based_include ".../localized/_/.../file" %}

At runtime, the single underscore ("_") path component is replaced
with the localization key.

To create a localized version of EZID:

1) Add an entry to the LOCALIZATIONS variable.

2) Create versions of localized components.  Search for directories
named "localized", or grep template files for "host_based_include"
tags.

3) Place static files under the "static" directory, following the same
naming pattern.  For example, place static images under
static/images/localized/{key}/.

4) If running under Apache and if using SSL, then each localization
requires its own SSL certificate.  The certificates should be
referenced from separate <VirtualHost> sections in the SSL
configuration file.