# read-components [![Build Status](https://travis-ci.org/paulmillr/read-components.svg?branch=add-travis)](https://travis-ci.org/paulmillr/read-components)

Read Twitter Bower components.

Install with `npm install read-components`.

> read-components was made for automatic builders like [Brunch](http://brunch.io).
Automatic means you don’t need to specify bower files which will be built.
Instead, read-components reads root `bower.json`, opens `bower.json` of
all packages and their dependencies and auto-calculates concatenation order.

## Component JSON file must have `main` property.

Every component which is handled by bower must have "main" property in bower.json. You can specify this in your own `bower.json` in `overrides` section. See below for examples.

## Why

For automatic builds, read-components requires files to have `dependencies` and `main` properties specified.
But not all bower packages have `bower.json` with `main` property specified.
I’d say less than 50%. So parsing these will fail:

```js
// Root bower.json
{
  ...
  "dependencies": {
    "chaplin": "*"
  }
}

// bower_components/chaplin/bower.json
{
  ...
  "dependencies": {"backbone": "*"}
}

// bower_components/backbone/bower.json
{// no deps, no `main`}
```

read-components solves the problem by allowing user to specify `bower.json`
**overrides** in root config file.

For example, if your root bower.json looks like that

```json
{
  "dependencies": {"chaplin": "*"},
  "overrides": {
    "backbone": {
      "main": "backbone.js",
      "dependencies": {
        "underscore": "~1.5.0",
        "jquery": "~2.0.0"
      }
    }
  }
}
```

read-components will treate backbone bower.json as completed and will produce
correct output for automatic builders.

## Usage

Node.js:

```javascript
var read = require('read-components');

read('your-project-dir-with-bower.json', 'bower', function(error, components) {
  console.log('All components:', components);
});

read('.', 'bower', function(error, components) {});
```

Output is a list of packages like this:

```json
[{ "name": "d",
  "version": "1.0.2",
  "files": [ "/Users/john/project/bower_components/d/index.js" ],
  "dependencies": { },
  "sortingLevel": 2 },
{ "name": "e",
  "version": "1.0.1",
  "files": [ "/Users/paul/project/bower_components/e/index.js" ],
  "dependencies": { "d": "~1.0.0" },
  "sortingLevel": 1 } ]
```

Each package will also have `sortingLevel` and `files` specified.
You can use it to get concatenation order like this:

```javascript
// Note that it is sorted like this by default.
packages
  .sort(function(a, b) {
    var field = 'sortingLevel';
    return b[field] - a[field];
  })
  .map(function(pkg) {
    return pkg.files;
  });
```

## License

The MIT License (MIT)

Copyright (c) 2013 Paul Miller (http://paulmillr.com/)

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.