surik / hello_pubsub

Publisher-Subscriber implementation over hello framework

Hello PubSub

Publisher-Subscriber implementation over hello framework.

Building and installing

Use rebar for building:

rebar get-deps compile

You can use hello_pubsub in your own project:

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

and ensure hello_pubsub is starder before your application:

{applications, [hello_pubsub]}.

Using

hello_pubsub has the following environment options:

• pubsub_listener_url - URL for binding pubsub API. When hello_pubsub is started hello_pubsub handler will be binded to this listener. This makes pubsub API available on <listener_url>/pubsub. http://127.0.0.1:8081 by default.

• sink_listener_url - default URL for sending events. local means you will be getting notification on local node. local by default.

• connect_to - URL for client connect. local means all pubsub APIs will be evaluated on local node. local by default.

Example:

{ok, _} = application:ensure_all_started(hello_pubsub),
hello_pubsub:subscribe(<<"root">>, <<"sub_1">>, 
                       fun(Topic, Id, Msg) -> 
                           io:format("~s on ~s got ~p~n", [Id, Topic, Msg]) 
                       end),

% prints "sub_1 on root/event1 got <<"message">>" 
hello_pubsub:publish(<<"root/event1">>, <<"message">>),

% prints "sub_1 on root got <<"message">>" 
hello_pubsub:publish(<<"root">>, <<"message1">>),

% prints nothing because here isn't subscription for 'another_root'
hello_pubsub:publish(<<"another_root">>, <<"message">>),

hello_pubsub:unsubscribe(<<"sub_1">>).

% prints nothing because subscription no mote available
hello_pubsub:publish(<<"/root/event1">>, <<"message">>).

Topics are trees. You can subscribe to /root/ and receive events from all nested /root/... topics.