Add Pusher beams and code that enables push notifications handling (#68)

Author: fdocr

.gitignore

@@ -81,4 +81,7 @@ lint/tmp/
 # lint/reports/
 
 # Detekt Reports
-reports/
+reports/
+
+# Firebase config
+app/google-services.json

README.md

@@ -9,9 +9,9 @@ This is the official repository for the [dev.to](https://dev.to/)'s Android app.
 
 ## Design ethos
 
-DEV Android is an [WebView](https://developer.android.com/guide/webapps/webview) based application. This application is inspired by [Basecamp's approach](https://m.signalvnoise.com/basecamp-3-for-ios-hybrid-architecture-afc071589c25). We will grow to include more native code over time. 
+DEV Android is an [WebView](https://developer.android.com/guide/webapps/webview) based application. This application is inspired by [Basecamp's approach](https://m.signalvnoise.com/basecamp-3-for-ios-hybrid-architecture-afc071589c25). We will grow to include more native code over time.
 
-By leveraging webviews as much as possible, we can smoothly sync up with our web dev work. And where it makes sense, we can re-implement certain things fully native, or build entirely native features. Life's a journey, not a destination. 
+By leveraging webviews as much as possible, we can smoothly sync up with our web dev work. And where it makes sense, we can re-implement certain things fully native, or build entirely native features. Life's a journey, not a destination.
 
 ## Contributions
 
@@ -43,6 +43,11 @@ To see more detail about a task, run gradlew help --task <task>
 
 ```
 
+### Push Notifications
+
+For Push Notification delivery we use [Pusher Beams](https://pusher.com/beams). In order to get the app running locally you'll need a `google-services.json` configuration file from Firebase, otherwise you'll encounter the following error: `File google-services.json is missing. The Google Services Plugin cannot function without it.`
+
+You can [sign up or sign in on Firebase](https://firebase.google.com/) account for free in order to get the app working locally. Steps 1-4 under **Firebase for Android Push Notifications** in our [official docs](https://docs.dev.to/backend/pusher/#mobile-push-notifications) show how to set this up in more detail. Drop the resulting `google-services.json` file in the `app` folder and you'll be good to go.
 
 ### How to contribute
 

app/build.gradle.kts

@@ -30,7 +30,12 @@ dependencies {
     implementation(Libs.kotlin_stdlib_jdk8)
     implementation(Libs.browser)
 
+    implementation("com.google.firebase:firebase-messaging:18.0.0")
+    implementation("com.pusher:push-notifications-android:1.6.2")
+
     testImplementation(Libs.junit)
     androidTestImplementation(Libs.androidx_test_runner)
     androidTestImplementation(Libs.espresso_core)
 }
+
+apply(plugin = "com.google.gms.google-services")

app/src/main/AndroidManifest.xml

@@ -13,8 +13,9 @@
             android:roundIcon="@mipmap/ic_launcher_round"
             android:supportsRtl="true"
             android:theme="@style/AppTheme"
-            android:usesCleartextTraffic="true"
-            tools:ignore="GoogleAppIndexingWarning,UnusedAttribute">
+            tools:ignore="GoogleAppIndexingWarning,UnusedAttribute"
+            tools:replace="android:fullBackupContent"
+    >
         <activity
                 android:name=".view.main.view.MainActivity"
                 android:screenOrientation="portrait">

app/src/main/java/to/dev/dev_android/view/main/view/CustomWebViewClient.kt

@@ -9,6 +9,8 @@ import android.webkit.CookieManager
 import android.webkit.WebView
 import android.webkit.WebViewClient
 import androidx.browser.customtabs.CustomTabsIntent
+import com.pusher.pushnotifications.PushNotifications
+import java.lang.Exception
 
 class CustomWebViewClient(
     private val context: Context,
@@ -23,12 +25,32 @@ class CustomWebViewClient(
         "github.com/sessions/"
     )
 
+    private var registeredUserNotifications = false
+
     override fun onPageFinished(view: WebView, url: String?) {
         onPageFinish()
         view.visibility = View.VISIBLE
         super.onPageFinished(view, url)
     }
 
+    override fun doUpdateVisitedHistory(view: WebView?, url: String?, isReload: Boolean) {
+        val javascript = "JSON.parse(document.getElementsByTagName('body')[0].getAttribute('data-user')).id"
+        view?.evaluateJavascript(javascript) { result ->
+            if (result != "null" && !registeredUserNotifications) {
+                try {
+                    val userId = result.toString().toInt()
+                    PushNotifications.addDeviceInterest("user-notifications-$userId")
+                    registeredUserNotifications = true
+                }
+                catch (e: Exception) {
+                    println(e)
+                }
+            }
+        }
+
+        super.doUpdateVisitedHistory(view, url, isReload)
+    }
+
     override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {
         if (view.originalUrl == "https://dev.to/signout_confirm" && url == "https://dev.to/") {
             view.clearCache(true)

app/src/main/java/to/dev/dev_android/view/main/view/MainActivity.kt

@@ -10,6 +10,7 @@ import android.view.View
 import android.webkit.ValueCallback
 import android.webkit.WebView
 import to.dev.dev_android.R
+import com.pusher.pushnotifications.PushNotifications
 import to.dev.dev_android.base.BuildConfig
 import to.dev.dev_android.base.activity.BaseActivity
 import to.dev.dev_android.databinding.ActivityMainBinding
@@ -29,6 +30,15 @@ class MainActivity : BaseActivity<ActivityMainBinding>(), CustomWebChromeClient.
         setWebViewSettings()
         savedInstanceState?.let { restoreState(it) } ?: navigateToHome()
         handleIntent(intent)
+        PushNotifications.start(getApplicationContext(), BuildConfig.pusherInstanceId);
+        PushNotifications.addDeviceInterest("broadcast");
+    }
+
+    override fun onResume() {
+        if (intent.extras != null && intent.extras["url"] != null) {
+            binding.webView.loadUrl(intent.extras["url"].toString())
+        }
+        super.onResume()
     }
 
     override fun onSaveInstanceState(outState: Bundle) {

build.gradle.kts

@@ -10,7 +10,7 @@ buildscript {
         val agpVersion = findProperty("version.com.android.tools.build..gradle") as String
         classpath("com.android.tools.build:gradle:$agpVersion")
         classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion")
-
+        classpath("com.google.gms:google-services:4.2.0")
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }

buildSrc/src/main/kotlin/Android.kt

@@ -40,6 +40,8 @@ fun Project.configureBuildConfig(android: BaseExtension) {
     android.buildTypes.all {
         resValue("string", "baseUrl", extra.string("chrome.baseUrl"))
         buildConfigString("baseUrl", extra.string("chrome.baseUrl"))
+        resValue("string", "pusherInstanceId", extra.string("pusher.instanceId"))
+        buildConfigString("pusherInstanceId", extra.string("pusher.instanceId"))
         resValue("string", "userAgent", extra.string("chrome.userAgent"))
         buildConfigString("userAgent", extra.string("chrome.userAgent"))
     }

gradle.properties

@@ -1,6 +1,7 @@
 ## dev.to configurations
 chrome.baseUrl=https://dev.to/
 chrome.userAgent=DEV-Native-android
+pusher.instanceId=cdaf9857-fad0-4bfb-b360-64c1b2693ef3
 
 # Android release configurations
 android.targetSdkVersion=28