# Region

The `region` module is a module meant to standardize the detection of various
regions, such as EU or APAC. It exposes functions that can test if a locale
belongs to various regions. It can also simply lookup the region for a given
locale.

So far, the only region supported is EU, but the module is designed to be
easily extendable when the need to support other regions pops up.

## Usage Examples

Loading the root module:
```javascript
var region = require('bv-ui-core/lib/region');

region.hasLocale('europe', 'en_US'); // false
region.hasLocale('europe', 'en_GB'); // true

region.hasTerritory('europe', 'US'); // false
region.hasTerritory('europe', 'GB'); // true

region.lookupTerritory('US'); // unsupported
region.lookupTerritory('GB'); // europe

region.lookupLocale('en_US'); // unsupported
region.lookupLocale('en_GB'); // europe

```
This can be useful when you'll have to support detection of multiple regions.
As only the EU region is supported for now, it's not particularly useful yet.

Loading a specific region module:
```javascript
var europe = require('bv-ui-core/lib/region/europe');

europe.hasLocale('en_US'); // false
europe.hasLocale('en_GB'); // true

europe.hasTerritory('US'); // false
europe.hasTerritory('GB'); // true

// Get an Array with all the region's country codes.
var europeanTerritories = europe.listTerritories();

// If you prefer a map, you can require it directly.
var europeanTerritoryMap = require('bv-ui-core/lib/region/europe/territories');
```
This can be useful if you've no need for other regions and would like to shave
every last byte from your client-side code.

Errors will be thrown if invalid locale or territory codes are provided. This
is to protect the user against mistaking language codes for territory codes.
For example, 'fr' is the code for the French language, and 'FR' is the code
for France. To avoid the case where `region.hasTerritory('europe', 'fr');`
returns false, we throw an error.

```javascript
var region = require('bv-ui-core/lib/region');

// The user likely meant to check 'FR'. To avoid confusion, we throw an error
// instead of just returning false.
region.hasTerritory('europe', 'fr');
```