This software provides an Erlang client for Firebase Cloud Messaging.

This supports both Android & iOS notifications.

The project is heavily inspired from pdincau/gcm-erlang. I would like to thank Paolo for the same.

Using fcm-erlang you can:

1. start several gen_servers representing different FCM applications defined by different FCM API keys
2. send notification messages to Mobile devices registered to your specific application and registered to FCM using a specific registration id

fcm-erlang does only provide support for JSON messages.

fcm-erlang user erlang.mk as make system. To compile

$ make

To generate release

$ make rel

You can use fcm_app as a dependency in your rebar.config:

{deps , [
    {fcm, ".*", {git, "https://github.com/softwarejoint/fcm-erlang.git", {tag, "1.0.1"}}}
]}.

make rel will create a release under _rel/fcm directory.

$ cd _rel/fcm
$ bin/fcm console

While fcm-erlang is running you can start several supervised gen_servers, one for each FCM application. Every gen_server is defined by an atom used internally for registration and by a FCM API key.

3> fcm:start(foo, "myapikey").
{ok,<0.60.0>}
4> fcm:start(bar, "myotherapikey").
{ok,<0.65.0>}
5> fcm:start(baz, "mylastapikey").
{ok,<0.79.0>}

You can stop a gen_server representing a FCM Application using:

6> fcm:stop(foo).

At any time you can send a FCM message to one or more mobile devices by calling:

7> fcm:push(RegisteredName, RegIds, Message).
7> fcm:sync_push(RegisteredName, RegIds, Message).
7> fcm:push(RegisteredName, RegId, Message).
7> fcm:sync_push(RegisteredName, RegId, Message).

Where

* `RegistereName` is the atom used during registration
* `RegId` is Registration Id specified as Erlang binary (e.g., `<<"APA91bHun4MxP5egoKMwt2KZFBaFUH-1RYqx...">>`)
* `RegIds` is a list (max 1000 elements) of `RegId`	* `Message` is an Erlang Map or TupleList representing the data you want to send to the device.

In order to understand Message payload see Message Syntax.

The JSON message is built using jsx in the module fcm.erl and in the end will have the following form:

{
  "registration_ids" : ["APA91bHun4MxP5egoKMwt2KZFBaFUH-1RYqx..."],
  "data" : {
    "message" : "a message"
  },
  "time_to_live" : 3600,
  "collapse_key" : "your_update"
}

You can send this message using:

8> fcm:push(RegisteredName, RegIds, [{<<"data">>, [
8>     {<<"message">>, <<"a message">>}
8> ]}, {<<"time_to_live">>,3600}, {<<"collapse_key">>,<<"your_update">>}]).

or simply:

8> fcm:push(RegisteredName, RegIds, [{<<"data">>, [
8>     {<<"message">>, <<"a message">>}
8> ]}]).

fcm-erlang will push the message for you to Firebase Cloud Messaging servers and will parse the JSON provided as result.

In order to understand errors see: Interpreting an error response.