Twerl

An Erlang client for the Twitter Streaming API.

Goals

A lightweight client which can consume the Twitter Streaming API.
A client manager which allows you to change the search queries without losing any data (WIP).

Usage

You probably want to include it as a depedency in Rebar:

{deps,
  [
    {twerl, ".*", {git, "https://github.com/lucaspiller/twerl.git", "master"}},
  ]
}.

Client

Generate auth headers:

Headers = stream_client_util:generate_auth_headers(TwitterUsername, TwitterPassword).

Generate params:

{ok, Params} = stream_client_util:keywords_to_track(["erlang"]).

Build a callback function:

Callback = fun(Data) ->
  Tweet = proplists:get_value(<<"text">>, Data),
  io:format("Erlang <3: ~s~n", [Tweet])
end.

Start streaming:

stream_client:connect(stream_client_util:filter_url(), Headers, Params, Callback).

Manager

The function stream_client:connect/4 blocks, and only returns once the stream ends. You can use the manager which is a simple gen_server which wraps the functionality and adds some nice additions, such as allowing you to change filter params and the callback.

Start the manager:

stream_client_manager:start_link(awesomeness).

Set auth headers:

Headers = stream_client_util:generate_auth_headers(TwitterUsername, TwitterPassword),
stream_client_manager:set_headers(awesomeness, Headers).

Set params:

{ok, Params} = stream_client_util:keywords_to_track(["erlang"]),
stream_client_manager:set_params(awesomeness, Params).

Start streaming (you can set a callback after, and change it without losing data):

stream_client_manager:start_stream(awesomeness).

Set a callback:

stream_client_manager:set_params(awesomeness, fun(Data) ->
  Tweet = proplists:get_value(<<"text">>, Data),
  io:format("Erlang <3: ~s~n", [Tweet])
end).

Stop streaming:

stream_client_manager:stop_stream(awesomeness).

Stop the manager:

stream_client_manager:stop(awesomeness).

One of the goals is to be able to change the filter params without losing any data. This is still WIP as data could be lost or duplicated.

Development

Start an Erlang shell with reloader support:

make dev

Compile new code:

make compile

Run tests (written in espec):

make test

Contributing

Fork the project.
Make your feature addition or bug fix.
Use the same indentation (4 spaces).
Add a line to CHANGELOG.md describing your change.
Add tests. Pull requests without tests will be ignored.
Send me a pull request. Bonus points for topic branches.

License

MIT License. See LICENSE.md for details.

mworrell/twerl