# Imgix

Official Ruby Gem for signing [imgix](http://imgix.com) URLs. Tested under 1.9.2, 2.2.2, JRuby 1.7.19, and Rubinius 2.2.7.

[![Build Status](https://travis-ci.org/imgix/imgix-rb.png?branch=master)](https://travis-ci.org/imgix/imgix-rb)


## Installation

Add this line to your application's Gemfile:

``` ruby
gem 'imgix'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install imgix


## Usage

Simply initialize a client with a host and your token. You can optionally generate secure URLs.

Now, if you have the URL ready to go, you can call `sign_path` to get the Imgix URL back. If you would like to manipulate the path parameters you can call `path` with the resource path to get an Imgix::Path object back.

``` ruby
client = Imgix::Client.new(host: 'your-subdomain.imgix.net', token: 'your-token', secure: true)

client.sign_path('/images/demo.png?w=200')
#=> https://your-subdomain.imgix.net/images/demo.png?w=200&s=2eadddacaa9bba4b88900d245f03f51e

# OR
client.path('/images/demo.png').to_url(w: 200)

# OR
path = client.path('/images/demo.png')
path.width = 200
path.to_url

# OR
client.path('/images/demo.png').width(200).height(300).to_url

# Some other tricks
path.defaults.width(300).to_url # Resets parameters
path.rect(x: 0, y: 50, width: 200, height: 300).to_url # Rect helper
```


## Domain Sharded URLs

Domain sharding enables you to spread image requests across multiple domains. This allows you to bypass the requests-per-host limits of browsers. We recommend 2-3 domain shards maximum if you are going to use domain sharding.

In order to use domain sharding, you need to add multiple domains to your source. You then provide a list of these domains to a builder.


``` ruby
client = Imgix::Client.new(hosts: ['your-subdomain-1.imgix.net',
  'your-subdomain-2.imgix.net'])
```

By default, shards are calculated using a checksum so that the image path always resolves to the same domain. This improves caching in the browser. However, you can also specify cycle that simply cycles through the domains as you request them.


``` ruby
client = Imgix::Client.new(hosts: ['your-subdomain-1.imgix.net',
  'your-subdomain-2.imgix.net'], shard_strategy: :cycle))
```


## Multiple Parameters

When the imgix api requires multiple parameters you have to use the method rather than an accessor.

For example to use the [noise reduction](http://www.imgix.com/docs/urlapi/enhance#nr-nrs) options:

``` ruby
path.noise_reduction(50,50)
```

## URL encoding and signed ImgIX URLs

Some important third parties (like Facebook) apply URL escaping to query string components, which can cause correctly signed ImgIX URLs to to be transformed into incorrectly signed ones. We URL encode the query part of the URL before signing, so you don't have to worry about this.

## What is the `ixlib` param on every request?

For security and diagnostic purposes, we sign all requests with the language and version of library used to generate the URL.

This can be disabled by including `:`include_library_param: false` in the instantiation Hash parameter for `Imgix::Client`:

```ruby
client = Imgix::Client.new({ include_library_param: false })
```

## Contributing

See the [contributing guide](Contributing.markdown).