# Ref Inspector

Referer parser library.


## Setup

### Dependency

To use Ref Inspector with your projects, edit your `mix.exs` file and add the
required dependencies:

```elixir
defp deps do
  [ { :ref_inspector, "~> 0.9" },
    { :yamerl,        github: "yakaz/yamerl" } ]
end
```

You should also update your applications to include all necessary projects:

```elixir
def application do
  [ applications: [ :ref_inspector ]]
end
```

### Referer Database

Using `mix ref_inspector.yaml.download` you can store a local copy of the
regexes database in the configured path. This database is taken from the
[referer-parser](https://github.com/snowplow/referer-parser) project.

The local path of the downloaded file will be shown to you upon command
invocation.

### Configuration

Add the path to the referer database you want to use to your project
configuration:

```elixir
use Mix.Config

# static configuration
config :ref_inspector,
  yaml: Path.join(Mix.Utils.mix_home, "ref_inspector/referers.yml")

# system environment configuration
config :ref_inspector,
  yaml: { :system, "SOME_SYSTEM_ENV_VARIABLE" }
```

The shown path is the default download path used by the mix task.

Upon application start the database will be automatically loaded.
You can always reload it like this:

```elixir
:ref_inspector
|> Application.get_env(:yaml)
|> RefInspector.load()
```


## Usage

```elixir
iex(1)> RefInspector.parse("http://www.google.com/search?q=ref_inspector")
%RefInspector.Result{
  referer: "http://www.google.com/search?q=ref_inspector",
  medium:  "search",
  source:  "google",
  term:    "ref_inspector"
}
```

_Medium_ will be one of `:unknown`, `:email`, `:search` or `:social`
(always an atom). If configured to do so it might also be `:internal`.

_Source_ will be `:unknown` (as atom) if nothing was matched, otherwise a string
with the detected provider.

_Term_ will be `:none` (as atom) if no query parameters were given to parse or the
provider does not send any terms to detect (mostly social or email referers).
Otherwise it will be an unencoded string will the term passed (can be empty).

_Referer_ will return the passed referer unmodified.

### Internal Domains

To exclude some domains from parsing you can mark them as `:internal` using
your configuration:

```elixir
config :ref_inspector,
  internal: [ "www.example.com", "www.example.org" ]
```

If a referer matches (== ends with) at least one of the configured domains
(paths ignored!), it will return a result with the medium `:internal`.
Both `:source` and `:term` will be left at the initial/unknown state not
intended for further processing.


## Testing

Some (mix task) tests may download files from the internet.
These tests are all tagged `:download` to allow skipping them.


## Resources

- [referer-parser](https://github.com/snowplow/referer-parser)
- [yamerl](https://github.com/yakaz/yamerl)


## License

[Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0)

_Referers.yml_ taken from the [referer-parser](https://github.com/snowplow/referer-parser)
project. See there for detailed license information about the data contained.