# ![http.rb](https://raw.github.com/httprb/http.rb/master/logo.png)

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## About

HTTP (The Gem! a.k.a. http.rb) is an easy-to-use client library for making requests
from Ruby. It uses a simple method chaining system for building requests, similar to
Python's [Requests].

Under the hood, http.rb uses [http_parser.rb], a fast HTTP parsing native
extension based on the Node.js parser and a Java port thereof. This library
isn't just yet another wrapper around Net::HTTP. It implements the HTTP protocol
natively and outsources the parsing to native extensions.

[requests]: http://docs.python-requests.org/en/latest/
[http_parser.rb]: https://github.com/tmm1/http_parser.rb


## Another Ruby HTTP library? Why should I care?

There are a lot of HTTP libraries to choose from in the Ruby ecosystem.
So why would you choose this one?

Top three reasons:

1. **Clean API**: http.rb offers an easy-to-use API that should be a
   breath of fresh air after using something like Net::HTTP.

2. **Maturity**: http.rb is one of the most mature Ruby HTTP clients, supporting
   features like persistent connections and fine-grained timeouts.

3. **Performance**: using native parsers and a clean, lightweight implementation,
   http.rb achieves the best performance of any Ruby HTTP library which
   implements the HTTP protocol in Ruby instead of C:

  | HTTP client              | time      |
  |--------------------------|-----------|
  | curb (persistent)        | 2.519088  |
  | em-http-request          | 2.731645  |
  | Typhoeus                 | 2.851911  |
  | StreamlyFFI (persistent) | 2.853786  |
  | http.rb (persistent)     | 2.970702  |
  | http.rb                  | 3.588964  |
  | HTTParty                 | 3.931913  |
  | Net::HTTP                | 3.959342  |
  | Net::HTTP (persistent)   | 4.043674  |
  | open-uri                 | 4.479817  |
  | Excon (persistent)       | 4.618361  |
  | Excon                    | 4.701262  |
  | RestClient               | 26.832668 |

Benchmarks performed using excon's benchmarking tool

DISCLAIMER: Most benchmarks you find in READMEs are crap,
including this one. These are out-of-date. If you care about
performance, benchmark for yourself for your own use cases!

## Help and Discussion

If you need help or just want to talk about the http.rb,
visit the http.rb Google Group:

https://groups.google.com/forum/#!forum/httprb

You can join by email by sending a message to:

[httprb+subscribe@googlegroups.com](mailto:httprb+subscribe@googlegroups.com)

If you believe you've found a bug, please report it at:

https://github.com/httprb/http/issues


## Installation

Add this line to your application's Gemfile:

    gem "http"

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install http

Inside of your Ruby program do:

    require "http"

...to pull it in as a dependency.


## Documentation

[Please see the http.rb wiki](https://github.com/httprb/http/wiki)
for more detailed documentation and usage notes.


## Basic Usage

Here's some simple examples to get you started:


### GET requests

```ruby
>> HTTP.get("https://github.com").to_s
=> "<html><head><meta http-equiv=\"content-type\" content=..."
```

That's all it takes! To obtain an `HTTP::Response` object instead of the response
body, all we have to do is omit the #to_s on the end:

```ruby
>> HTTP.get("https://github.com")
=> #<HTTP/1.0 200 OK @headers={"Content-Type"=>"text/html; charset=UTF-8", "Date"=>"Fri, ...>
 => #<HTTP::Response/1.1 200 OK @headers={"Content-Type"=>"text/html; ...>
```

We can also obtain an `HTTP::Response::Body` object for this response:

```ruby
>> HTTP.get("https://github.com").body
 => #<HTTP::Response::Body:814d7aac @streaming=false>
```

The response body can be streamed with `HTTP::Response::Body#readpartial`:

```ruby
>> HTTP.get("https://github.com").body.readpartial
 => "<!doctype html><html "
```

In practice you'll want to bind the HTTP::Response::Body to a local variable (e.g.
"body") and call readpartial on it repeatedly until it returns `nil`.


### POST requests

Making POST requests is simple too. Want to POST a form?

```ruby
HTTP.post("http://example.com/resource", :form => {:foo => "42"})
```
Making GET requests with query string parameters is as simple.

```ruby
HTTP.get("http://example.com/resource", :params => {:foo => "bar"})
```

Want to POST with a specific body, JSON for instance?

```ruby
HTTP.post("http://example.com/resource", :json => { :foo => "42" })
```

Or just a plain body?

```ruby
HTTP.post("http://example.com/resource", :body => "foo=42&bar=baz")
```

Posting a file?

``` ruby
HTTP.post("http://examplc.com/resource", :form => {
  :username => "ixti",
  :avatar   => HTTP::FormData::File.new("/home/ixit/avatar.png")
})
```

It's easy!


### Proxy Support

Making request behind proxy is as simple as making them directly. Just specify
hostname (or IP address) of your proxy server and its port, and here you go:

```ruby
HTTP.via("proxy-hostname.local", 8080)
  .get("http://example.com/resource")
```

Proxy needs authentication? No problem:

```ruby
HTTP.via("proxy-hostname.local", 8080, "username", "password")
  .get("http://example.com/resource")
```


### Adding Headers

The HTTP gem uses the concept of chaining to simplify requests. Let's say
you want to get the latest commit of this library from GitHub in JSON format.
One way we could do this is by tacking a filename on the end of the URL:

```ruby
HTTP.get("https://github.com/httprb/http/commit/HEAD.json")
```

The GitHub API happens to support this approach, but really this is a bit of a
hack that makes it easy for people typing URLs into the address bars of
browsers to perform the act of content negotiation. Since we have access to
the full, raw power of HTTP, we can perform content negotiation the way HTTP
intends us to, by using the Accept header:

```ruby
HTTP.headers(:accept => "application/json")
  .get("https://github.com/httprb/http/commit/HEAD")
```

This requests JSON from GitHub. GitHub is smart enough to understand our
request and returns a response with `Content-Type: application/json`.

Shorter alias exists for `HTTP.headers`:

```ruby
HTTP[:accept => "application/json"]
  .get("https://github.com/httprb/http/commit/HEAD")
```


### Authorization Header

With [HTTP Basic Authentication](http://tools.ietf.org/html/rfc2617) using
a username and password:

```ruby
HTTP.basic_auth(:user => "user", :pass => "pass")
# <HTTP::Headers {"Authorization"=>"Basic dXNlcjpwYXNz"}>
```

Or with plain as-is value:

```ruby
HTTP.auth("Bearer VGhlIEhUVFAgR2VtLCBST0NLUw")
# <HTTP::Headers {"Authorization"=>"Bearer VGhlIEhUVFAgR2VtLCBST0NLUw"}>
```

And Chain all together!

```ruby
HTTP.basic_auth(:user => "user", :pass => "pass")
  .headers("Cookie" => "9wq3w")
  .get("https://example.com")
```


### Content Negotiation

As important a concept as content negotiation is to HTTP, it sure should be easy,
right? But usually it's not, and so we end up adding ".json" onto the ends of
our URLs because the existing mechanisms make it too hard. It should be easy:

```ruby
HTTP.accept(:json).get("https://github.com/httprb/http/commit/HEAD")
```

This adds the appropriate Accept header for retrieving a JSON response for the
given resource.


### Reuse HTTP connection: HTTP Keep-Alive

If you need to make many successive requests against the same host,
you can create client with persistent connection to the host:

``` ruby
begin
  # create HTTP client with persistent connection to api.icndb.com:
  http = HTTP.persistent "http://api.icndb.com"

  # issue multiple requests using same connection:
  jokes = 100.times.map { http.get("/jokes/random").to_s }
ensure
  # close underlying connection when you don't need it anymore
  http.close if http
end

```

If the optional code block is given, it will be passed the client with
persistent connection to the host as an argument and `client.close` will be
automatically called when the block terminates.
The value of the block will be returned:

``` ruby
jokes = HTTP.persistent "http://api.icndb.com" do |http|
  100.times.map { http.get("/jokes/random").to_s }
end
```

##### NOTICE

You must consume response before sending next request via persistent connection.
That means you need to call `#to_s`, `#parse` or `#flush` on response object.
In the example above we used `http.get("/jokes/random").to_s` to get response
bodies. That works perfectly fine, because `#to_s` reads off the response.

Sometimes you don't need response body, or need whole response object to
access it's status, headers etc instead. You can either call `#to_s` to
make sure response was flushed and then use response object itself, or use
`#flush` (syntax sugar for `#tap(&:to_s)` that will do that for you:


``` ruby
contents = HTTP.persistent "http://en.wikipedia.org" do |http|
  %w(Hypertext_Transfer_Protocol Git GitHub Linux Hurd).map do
    http.get("/wiki/#{target}").flush
  end
end
```


### Timeouts

By default, HTTP does not timeout on a request. You can enable per operation
(each read/write/connect call) or global (sum of all read/write/connect calls).

Per operation timeouts are what `Net::HTTP` and the majority of HTTP clients do:

``` ruby
HTTP.timeout(:per_operation, :write => 2, :connect => 5, :read => 10)
  .get "http://example.com"

# For convinience, you can omit timeout type in this case. So following has
# same result as the above:

HTTP.timeout(:write => 2, :connect => 5, :read => 10).get "http://example.com"
```

Global timeouts let you set an upper bound of how long a request can take,
without having to rely on `Timeout.timeout`:

``` ruby
HTTP.timeout(:global, :write => 1, :connect => 1, :read => 1)
  .get "http://example.com"
```

Uses a timeout of 3 seconds, for the entire `get` call.

*Warning!* You cannot use Celluloid::IO with timeouts currently.


## Supported Ruby Versions

This library aims to support and is [tested against][travis] the following Ruby
versions:

* Ruby 1.9.3
* Ruby 2.0.0
* Ruby 2.1.x
* Ruby 2.2.x
* Ruby 2.3.x
* JRuby 1.7.x
* JRuby 9000+

If something doesn't work on one of these versions, it's a bug.

This library may inadvertently work (or seem to work) on other Ruby versions,
however support will only be provided for the versions listed above.

If you would like this library to support another Ruby version or
implementation, you may volunteer to be a maintainer. Being a maintainer
entails making sure all tests run and pass on that implementation. When
something breaks on your implementation, you will be responsible for providing
patches in a timely fashion. If critical issues for a particular implementation
exist at the time of a major release, support for that Ruby version may be
dropped.

[travis]: http://travis-ci.org/httprb/http


## Contributing to http.rb

* Fork http.rb on GitHub
* Make your changes
* Ensure all tests pass (`bundle exec rake`)
* Send a pull request
* If we like them we'll merge them
* If we've accepted a patch, feel free to ask for commit access!


## Copyright

Copyright (c) 2011-2016 Tony Arcieri, Erik Michaels-Ober, Alexey V. Zapparov, Zachary Anker.
See LICENSE.txt for further details.
