README.md
nunjucks-date-filter
====================
[](https://travis-ci.org/piwi/nunjucks-date-filter)
[](https://codeclimate.com/github/piwi/nunjucks-date-filter)
This defines a `date` filter for [Nunjucks](http://mozilla.github.io/nunjucks/)
implementing [moment.js](http://momentjs.com/), a rich date manager.
Getting Started
---------------
You may install this plugin with this command:
```shell
npm install nunjucks-date-filter --save-dev
```
Usage
-----
You must first include the filter and then add it to your *nunjucks* environment:
```js
var dateFilter = require('nunjucks-date-filter');
var env = new nunjucks.Environment();
env.addFilter('date', dateFilter);
```
A shortcut is proposed in the package:
```js
var dateFilter = require('nunjucks-date-filter');
dateFilter.install(
[ env ] // by default, current nunjucks environment will be used
[ , custom_filter_name ] // by default, the filter will be named "date"
);
```
You can also define a default date format:
```js
var dateFilter = require('nunjucks-date-filter');
dateFilter.setDefaultFormat('YYYY');
```
Once it is installed, you can call the filter in your *nunjucks* templates:
```
// with no format
This blog has been created at {{ creation_date | date }}.
// with a custom format
This blog has been created at {{ creation_date | date("YYYY") }}.
// with an addition first
This blog has been created at {{ creation_date | date("add", 7, "days") | date }}.
```
*Momentjs* usage
----------------
The moment library proposes [a large set of date formats](http://momentjs.com/docs/#/displaying/format/)
you can use to customize the filter output. It also embeds [a huge set of methods](http://momentjs.com/docs/#/get-set/)
to manipulate dates. Any of these methods can be called using the filter, passing as many
arguments as needed (see example above).
Contributing
------------
In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit
tests for any new or changed functionality. Lint and test your code using [Mocha](http://mochajs.org/).