Firebase notifications

A Duct library that provides Integrant keys for managing notifications in Firebase Cloud Messaging.

Installation

Usage

Configuration

To use this library add the following key to your configuration:

:dev.gethop.notifications/firebase

This key expects a configuration map with one mandatory key:

• :google-credentials: A map with five elements:
  • project-id
  • private-key-id
  • private-key
  • client-id
  • client-email

Key initialization returns a Firebase record that can be used to perform the Firebase operations described below.

Configuration example

   :dev.gethop.notifications/firebase
   {:google-credentials {:project-id #duct/env ["G_CREDENTIALS_PROJECT_ID" Str]
                         :private-key-id #duct/env ["G_CREDENTIALS_PRIVATE_KEY_ID" Str]
                         :private-key #duct/env ["G_CREDENTIALS_PRIVATE_KEY" Str]
                         :client-id #duct/env ["G_CREDENTIALS_CLIENT_ID" Str]
                         :client-email #duct/env ["G_CREDENTIALS_CLIENT_EMAIL" Str]}}

Obtaining a Firebase record

If you are using the library as part of a Duct-based project, adding any of the previous configurations to your config.edn file will perform all the steps necessary to initialize the key and return a Firebase record for the associated configuration. In order to show a few interactive usages of the library, we will do all the steps manually in the REPL.

First we require the relevant namespaces:

user> (require '[integrant.core :as ig]
               '[dev.gethop.notifications.core :as core])
nil
user>

Next we create the configuration var holding the Firebase integration configuration details:

user> (def config {:google-credentials {:project-id (System/getEnv "G_CREDENTIALS_PROJECT_ID")
                                        :private-key-id (System/getEnv "G_CREDENTIALS_PRIVATE_KEY_ID")
                                        :private-key (System/getEnv "G_CREDENTIALS_PRIVATE_KEY")
                                        :client-id (System/getEnv "G_CREDENTIALS_CLIENT_ID")
                                        :client-email (System/getEnv "G_CREDENTIALS_CLIENT_EMAIL")}})
#'user/config
user>

Now that we have all pieces in place, we can initialize the :dev.gethop.notifications/firebase Integrant key to get a Firebase record. As we are doing all this from the REPL, we have to manually require dev.gethop.notifications.firebase namespace, where the init-key multimethod for that key is defined (this is not needed when Duct takes care of initializing the key as part of the application start up):

user> (require '[dev.gethop.notifications.firebase :as firebase])
nil
user>

And we finally initialize the key with the configuration defined above, to get our Firebase record:

user> (def fb-record (->
                       config
                       (->> (ig/init-key :dev.gethop.notifications/firebase))))
#'user/fb-record
user> fb-record
#dev.gethop.notifications.firebase.Firebase{:service-credentials #object[com.google.auth.oauth2.ServiceAccountCredentials
                                                              0x307d05cf
                                                              "ServiceAccountCredentials{...}"}
user>

Now that we have our Firebase record, we are ready to use the methods defined by the protocols defined in dev.gethop.notifications.core namespace.

Usage

send-notification

• parameters:
  • A Firebase record.
  • logger: usually a reference to :duct/logger key. But you can use any Integrant key derived from :duct/logger (such as :duct.logger/timbre).
  • recipient: registration token to send a message to. It can be a single value or a collection of multiple tokens.
  • message: a map with the information that will be send as a notification. The values can be strings, numbers, simple keywords or UUID's. They will be converted to strings due to a Firebase limitation.
  • options: optional configuration parameters that will be send in the Firebase message object. See the docs for available keys.
• returning value:
  • :success? true if the notification was successfully sent to all the recipients. false if sending the notification failed for at least one recipient.
  • :errors list of errors that happened when sending the notification. It's one error for each recipient.
• Example:

user> (core/send-notification fb-record logger "token1" {:header "Hello"} {})
{:success? true}

user> (core/send-notification fb-record logger ["token1" "invalid-token"] {:header "Hello"} {})
{:success? false
 :errors [{:recipient "invalid-token"
           :error com.google.firebase.messaging.FirebaseMessagingException
           :error-details "The registration token is not a valid FCM registration token"}]}

• Example with options:

user> (core/send-notification fb-record logger "token1" {:header "Hello"} {:android {:priority :high}
                                                                           :apns {:headers {:apns-priority "10"}
                                                                                  :payload {:content-available true
                                                                                            :badge 0}})
{:success? true}

send-notification-async

Same as send-notification, but returns a Clojure Future object. The return value can be obtained by derefing the object. Note that the notification will be sent no matter if it was derefed or not. This can be useful if we are not interested in the answer and we don't want to block the main thread.

user> (def result (core/send-notification fb-record logger "token1" {:header "Hello"} {}))
#'dev.gethop.notifications.firebase/a

user> result
#<Future@4413771e: :pending>

user> @result
(wait until the request is ended)
{:success? true}

License

Copyright (c) 2022 HOP Technologies

The source code for the library is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.