Filtr 

Filter javascript arrays using a MongoDB style syntax and is available for node.js
and the browser. It was originally written as an internal component for Seed,
but it had no other dependancies and seemed fit for use in the browser.

Installation

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Filtr is available on npm.

npm install filtr

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A browser build is available in the repository's dist folder.
Download the package and include either the normal or minimized build in your HTML header.

The browser build is fully AMD and CommonJS compatible and should work on all browser.

Features

Filtr is still in early development so expect this list to grow.

##### Expansive Query Language

* Comparators: $gt, $gte, $lt, $lte, $all, $exists, $mod, $eq, $ne, $in, $nin, $size
* Traversables: $or, $nor, $and

##### Data Helpers

* filtr.getPathValue returns the nested value in an object given a string path
* filtr.comparators are available directly for quick value testing

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``js
var query = filtr({ $gt: 15, $lt: 25 })
, results = query.test([ 5, 10, 17, 19, 25 ]);
// results == [ 17, 19 ];
`

#### Test options provide different output

Testing also supports a number of options passed in as the second argument.

spec*: output modifer
* _subset_: (default) return an array containing a subset of matched items
* _boolean_: return an array of the original length with each item being a boolean when object passed or failed.
* _index_: return an array of numbers matching the index of passed object in the original array
type*: input modifier
* _set_: (default) assert that the data provided is an array. test each item.
* _single_: assert that the data provided is a single item. return boolean.

Using the spec output modifier is an easy way to handle post processing of result sets
without having to match up a subset.

`js
var query = filtr({ $gt: 15, $lt: 25 })
, results = query.test([ 5, 10, 17, 19, 25 ], { spec: 'boolean' });
// results == [ false, false, true, true, false ];
`

#### Using paths for deep matching

Filtr also supports using paths for deep matching within a javascript object. Given the
following items, and sample queries.

`js
var dataComplex = [
{ a: { b: 100 }
, c: 'testC'
, d:
[ { e: 'world' } ]
}
, { a: { b: 50 }
, c: 'testC'
, d:
[ { e: 'universe' }
, { e: 'galaxy' } ]
}
];

var query1 = filtr({ 'a.b': { $gt: 75, $lt: 125 } });
, query2 = filtr({ 'a.b': { $gt: 25, $lt: 75 }, 'd[0].e': { $eq: 'universe' } });

var res1 = query1.test(dataComplex) // result would have the first item
, res2 = query1.test(dataComplex); // result would have the second item
`

A helper is also available that returns the value in a nested object given a string path.

`js
var hello = filtr.getPathValue('d[0].e', dataComplex[1]);
// hello == 'universe'
`

Where to Get Help

Please post issues to GitHub Issues.

Tests

Tests are written in the BDD styles for the [Mocha]() test runner using the
should assertion interface from Chai. Running tests is simple:

make test

A browser suite is also available at test/browser/index.js`. The same test definitions are
used in both contexts.

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Interested in contributing? Fork to get started. Contact @logicalparadox
if you are interested in being regular contributor.

#### Contibutors

* Jake Luer (Github: @logicalparadox) (Twitter: @jakeluer) (Website)

License

(The MIT License)

Copyright (c) 2011-2012 Jake Luer

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.