Push Notifications on Android GM version: GM: Studio 1.4.1804 Professional (2018-03-18) Target platform: Android Download: https://marketplace.yoyogames.com/assets/4818/push-notifications-example Links: N/A Latest change: 2018-08-09 Level: Advanced Summary This tutorial will explain how you can make your own Push Notifications on Android. The tutorial will first cover the local push notifications (which means that a user gets a notification after a specific amount of time) and the remote push notifications (for example, you receiving a WhatsApp message from another user). I created an example in which you can see the code yourself. You can download it from YoyoGames’s Marketplace: https://marketplace.yoyogames.com/assets/4818/push-notifications-example Please note that if you want to fully understand this tutorial, it is strongly advisable to read my earlier tutorial about “Online Highscores” first since we will use the same database system: https://forum.yoyogames.com/index.php?threads/online-highscores.4291/ Table of contents Introduction Chapter 1: Local Push Notifications Chapter 2: Remote Push Notifications: Google Cloud Messaging Chapter 3: Remote Push Notifications: In Altervista Chapter 4: Remote Push Notifications: In GameMaker: Studio Conclusion Error solving: 401 unauthorised Changelog Introduction Have you ever wanted to create an awesome app where players would be able to battle each other? After you came to the conclusion that making a real-time online app was too difficult, you started searching for a turn-based method (of which chess is the most famous example). But how could you let the other player know it is their turn to play? In this tutorial this problem will be solved. I will try to go in-depth and tell why and how this can be done using push notifications. First we will be going through the local push notifications and secondly we will explore the remote push notifications. YoyoGames has already written a decent tutorial about this subject, so I strongly recommend you reading that first: http://www.yoyogames.com/blog/31. After reading the introductory blog post, you should know what the general idea is. Since Yoyo also wrote a decent introductory tutorial about remote push notifications on Android, I strongly suggest that you read that too so you know what I'm talking about: http://help.yoyogames.com/hc/en-us/articles/216753458-Push-Notifications-Android. Now you’re done reading that whole lot of information, it’s time to start to go in-depth and look into the myths of push notifications. This tutorial and all its assets are completely free, there is no need for any credit at all to Appsurd. We do appreciate if you rate the script in the Marketplace such that we know what can be improved. Thanks in advance and enjoy the tutorial! Chapter 1: Local Push Notifications Local Push Notifications are actually quite easy to implement. After reading YoyoGames’ tutorial, it should be clear how you should use it. Don’t forget to download Yoyo’s asset https://marketplace.yoyogames.com/assets/2008/google-play-services from the Marketplace and add it to your project. I’ll now just present you some useful functions. The notifications are local, implying that the local push notification will be send to the player’s device only. Generally, one could use this after a user hasn’t opened your app for a while, and you want to grab his/her attention with a special offer or maybe a reminder of getting his/her daily reward. Pushing a notification is done using the function push_local_notification(fire_time, title, message, data). An example is shown below. Code: var time = date_inc_second(date_current_datetime(),15); push_local_notification(time, "My App name", "Just for testing local push notifications", "This is a test message from the local push notification."); The first argument of the function is the fire time, which is the time at which the notification should pop up. In this example, I used date_inc_second, but normally date_inc_day is all that you need. Just look into the documentation on how to use this function specifically, it’s been explained quite well there. The second argument is the title of your message, which you would mostly want to be the title of your game or app. The third argument is the message displayed below the title, here you should place the message you want to give to the player. An example is: “Come back and claim your daily reward!” The fourth argument is the data passed to the app. Unfortunately, it does not matter whether the player opens the app via the local push notification or the player swipes it away and opens the app in the normal way, in both scenarios the data is transmitted to the app. This makes it in my opinion quite useless, but maybe you can think of a useful application for it. Just as I said before, the data of the notification can be received by the app. First load the player’s registration ID in the Create Event. Code: // Initialise register_id ini_open("File.ini"); global.reg_id = ini_read_string("Reg","Reg",""); ini_close(); Enter the following code in the Asynchronous Push Event of a persistent object which is ALWAYS present, also at the very start of the game. Putting it in another object may cause errors! Code: /// Handle the data of the push notification var type = ds_map_find_value(async_load, "type"); var status = ds_map_find_value(async_load, "status"); if status == 0 { //error of some kind var error = ds_map_find_value(async_load, "error"); show_message_async("Error:#" + string(error)); } else { // registering for the first time (this is always called at the start of the app) if type == "register" { var reg_id = ds_map_find_value(async_load, "reg_id"); // If the player's hasn't registered before, save the registration ID to the ini file if reg_id != global.reg_id { global.reg_id = reg_id; ini_open("File.ini"); ini_write_string("Reg","Reg",global.reg_id); ini_close(); show_message_async("New register ID:#"+string(global.reg_id)); } else { show_message_async("Old register ID:#"+string(global.reg_id)); } } else // show the data received { var data = ds_map_find_value(async_load, "data"); show_message_async("Data:#"+string(data)); } } This script is actually almost the same as on http://www.yoyogames.com/blog/31, with the exception that I check if the player is new (and thus requires to get a new register ID) or has played the game before. The usefulness of storing the register ID is not really there, since you do not use it at all for local push notifications. We will however see that it is required to store the registration ID whenever you want to use remote push notifications. More about that in chapters 3 and 4. There are three more functions available for the local push notifications. Push_get_first_local_notification retrieves the first local notification which is coming up. Push_get_next_local_notification can be used after the previous function and simply gives the next notification. Push_cancel_local_notification can be used to cancel a specific notification which you had already set before. The usefulness of these functions is covered by an example which I took directly from Yoyo’s manual as it’s just perfect to illustrate how to use them. Code: var map = ds_map_create(); // Find the first notification var ntf = push_get_first_local_notification(map); // As long as this notification exists while(ntf >= 0) { // If the notification is a daily reward, remove it var data = ds_map_find_value(map, "data"); if data == "Daily_Reward" { push_cancel_local_notification(ntf); } // Go to the next notification ntf = push_get_next_local_notification(map); } ds_map_destroy(map); That’s actually it for the local ones. Now let’s continue the tutorial with the more interesting stuff: remote push notifications. Chapter 2: Remote Push Notifications: Google Cloud Messaging Remote push notifications are almost the same as local ones, except that the developer or other players can set the notification for someone else. This ensures the possibility to create a chat and the other chatter receiving a message as a push notification, just like WhatsApp does. In order to be able to start the whole process, we should first create a project in Firebase. Just a small side note: since September 2016 it is obligatory to use Firebase Cloud Messaging. Before that, there was another system simply called Google Cloud Messaging. Please DO NOT use the old system anymore, it might cause strange errors! Let’s go to https://console.firebase.google.com/ and login with your Google account (preferably use the same one as you use for your apps on the Google Play Store). Of course you may create a new account for it as well. Now let’s create a new project, so press “Create new project” as shown in Figure 1. Figure 1: The Firebase welcome screen. Click on "Add project" to create a new project. After pressing the “Create new project” , you are prompted to give your project’s name. I will choose “Push Notifications Tutorial” in this case. I recommend you to use the name of your game as a project name. Furthermore, select your country. Figure 2: Creating a new project. Preferably choose the project name to be the name of your game. Now press “Create Project”. Now your project is being created. This could take a couple of seconds. After that, you are forwarded to a screen and quickly after that, you will see the overview of the project. See Figure 3. Figure 3: The overview of the your project. We will only need one function in this tutorial, all others are not interesting for now. Notice your project name in the top left orange frame, this should of course be the same as the project name you just entered. Until now, we created a project only so we need to get some information about the project to be able to use the push notifications. Let’s go to the “Project settings” for that (see Figure 3). You should now be seeing something like I have (see Figure 4). Figure 4: The general settings of your project. Go to the “Cloud Messaging” tab as indicated by the orange frame. Here you see the general section of the settings, thus some general information about your project. First of all, your project name is displayed. Thereafter, the public-facing name is shown. This is the name visible to your users, so I would recommend to leave it as it is. Below that, your project ID is displayed. We DO NOT use this ID, since we cannot use it. And last but not least, the Web API key is shown. As the name already suggests, this key is for web developing, so it is of no interest to us. Next to the general tab, there is a tab called “Cloud Messaging” as shown in Figure 4 by the orange frame. Click on it to go to the “Cloud Messaging” section. You should now see the screen shown in Figure 5. Figure 5: The section “Cloud Messaging” in the settings of your project. The most important codes are the sender ID and the Server key. Here we have exactly what we need. First of all, copy the sender ID code (see Figure 5) and save it somewhere because we will need it further on in the tutorial! You will use this code for GameMaker: Studio to identity with Firebase. After that, copy the code below the Server key (see the lower orange frame in Figure 5) and save it somewhere because we will need this too! This is to make sure that your PHP script (which we will create in chapter 3 of this tutorial) is able to connect to the Cloud Messaging service. And actually that’s it! You may close this page as we do not need it anymore in this tutorial. Do remember to save the codes I mentioned, since we definitely need those. Let’s continue the tutorial and set up a database system. Chapter 3: Remote Push Notifications: In Altervista Now we have set up the project correctly in the Google Firebase environment, it is time to look into the PHP side. For me, it was quite weird to find out that you could not directly communicate from GameMaker: Studio with the Google Cloud Messaging server. This makes it a little more complicated, but since Google chose for this, we will have to deal with it! On the other hand, communication with another player requires you to have his registration ID, so it’s quite logical actually! So let’s get started! This is the part that YoyoGames’s tutorial is actually lacking information on how you should do this, especially if your knowledge about web communication is not too big. In this tutorial, we will use a free website and a database, known as Altervista. If you do not know what I’m talking about, please follow my earlier posted tutorial “Online Highscores” https://forum.yoyogames.com/index.php?threads/online-highscores.4291 first, and especially the first two chapters of that tutorial contain vital information about the registering on and working with Altervista. From now on, I assume that you have an Altervista account and that you know how to add a table and how to add PHP files. If you do not, please recall the tutorial “Online Highscores” for more information. It’s time to move into the coding of the online part. Login to Altervista and go to your Dashboard. Then you should see something like this: Figure 6: The Dashboard of Altervista. First of all go to the “File Management” section as in the upper orange frame. There I will create a new map, called “PushNotifications”. Maybe your app’s file name is already there, then you can use the same map and you do not have the create a new one. Inside the map, we will create two PHP files: one for registering and one for sending the notification to the GCM server. First create a PHP file called addpush. Open it and put the following code into it. Do not forget to change the names tutorialappsurd (account name) and my_tutorialappsurd (database name) and the 1234 (secret key) to the ones you have chosen! Code: <?php // Connect to database $db = new PDO('mysql:host=localhost;dbname=my_tutorialappsurd', 'tutorialappsurd'); // Check secret key, if correct, then insert name and score $secretKey = "1234"; if($secretKey == $_POST['hash']) { // Send variables for the MySQL database class. $sql = "INSERT INTO PushNotificationsIDs VALUES (NULL, :reg_id)"; $stmt = $db->prepare($sql); $stmt->bindParam(':reg_id', $reg_id, PDO::PARAM_STR); // Get reg_id from URL string $reg_id = $_POST['reg_id']; // Execute statement $stmt->execute(); echo '1'; } else { echo '0'; } ?> In this script, first a connection is ensured with the database. Just to remind you, do not forget to change the dbname on the first line to your my_accountname and the second one to your account name. In my case, that is my_tutorialappsurd and tutorialappsurd. Also carefully check your secret key. And finally, check the tablename (which in my case is PushNotificationsIDs). After the connection is established, the secret key is compared with the one on the server. If both are equal, first the statement is prepared. Then the player’s registration ID is attached to the statement. And finally, the statement is executed. You need to call this script only once, so only when the player opens your app for the very first time, but I will explain this in detail in chapter 4. Now create the second script sendpush and put the following code into it. Code: <?php // Connect to database $db = new PDO('mysql:host=localhost;dbname=my_tutorialappsurd', 'tutorialappsurd'); $secretKey = "1234"; if($secretKey == $_POST['hash']) { // Get all data from the table $sql = "SELECT reg_id FROM PushNotificationsIDs"; // Prepare statement $stmt = $db->prepare($sql); // Execute statement $stmt->execute(); // Fetch all results and put them in an array $rows = $stmt->fetchAll(PDO::FETCH_ASSOC); foreach ($rows as $row) { $list_reg_id[] = $row['reg_id']; } //print_r($list_reg_id); // Check if the array isn't empty if ($list_reg_id == "") { echo "No push ID's found"; exit(); } // Initialize curl $ch = curl_init(); $api_key = "AIzaSyBTAM******************"; // Enter variables (the Authorization key is the Server key from Firebase) $header = array( 'Authorization: key=' . $api_key, 'Content-Type: application/json' ); // Enter variables for the push notifications itself (you may change these of course) $body = array( 'data' => array( 'ntf_title' => 'Tutorial Push Notification', 'ntf_message' => 'Just for testing remote push notifications', ), 'registration_ids' => $list_reg_id ); // Setting some parameters, please do not change this curl_setopt($ch, CURLOPT_URL, 'https://android.googleapis.com/gcm/send'); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_HTTPHEADER, $header); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body)); // Execute posting to GCM $result = curl_exec($ch); if ($result === FALSE) { die("Curl failed: " . curl_error($ch)); } // Results of post in $result echo $result; } else { echo '0'; } ?> And again, don’t forget to change the first line containing your account name and database name. Also check the table name and the secret key! Just as in the previous script, at first a connection is made with the database. After that, the secret key is compared to the one on the server. If correct, all registration IDs known by the server are gathered and put together in a list. Then curl is initialised. This set of functions takes care of the POST request to the GCM server. You will see the so called API key in the script. Here you should put in the code from the Server key from the Firebase environment which we saved in chapter 2. After that, the title and message of the request are entered. You may of course change these values into whatever you want. Directly after that, all parameters used by the GCM are set up. Do not change these, otherwise you might get weird errors! Finally, the created request is posted to the GCM server. Just a final remark about this script, when you are curious to know what a certain function does, try to google it first, there are many (also non-GameMaker) examples available which explain the PHP and Curl functions in a very clear way. This script creates an array of all users known in the database. Maybe you want to send a push notification to a specific user only. You will then need to store (and get) the registration ID of the other player and submit that to the GCM. I cannot give one a cut-and-clear answer to this, since the final construction of the database and the PHP files are different whenever you want something different. I’m afraid you will have to figure it out alone, but I assume you’re almost a professional GameMaker developer, so I’m sure you can do it. Now it’s time to create a database. Go back to your Dashboard (see Figure 6) and click this time on the lower orange frame on “Access to PHPMyAdmin”. Now a new tab opens. Click in the left column on your my_tutorialappsurd database. You will see something comparable with the following figure. Figure 7: Creating a new table in the PHPMyAdmin environment in Altervista. Now enter a suitable name for your table, such as PushNotificationsIDs (preferably the name of your game + something like IDs). We will need two columns, so set the number of columns to 2. Then press “Go”. Go to the first row under “Name” and enter the word id. Leave the Type to INT. Fill at Length/Values the value 10 and check the checkmark in the one but last column called “A_I”. This ensures that each player in the list gets its own id and that registration IDs will not be overwritten accidently. Now continue on the second row and enter reg_id under “Name” and choose VARCHAR as “Type” and fill in the value 1000 in “Length/values”. This means that reg_id is a string with a maximal length of 1000 characters. This is all you need, so you can save the table now. This means that we are finished in Altervista. In the next chapter, we will see how you can code in GameMaker: Studio such that you can actually use the remote push notifications in your own game! Chapter 4: Remote Push Notifications: In GameMaker: Studio In the previous chapter, we went through all code in Altervista, such that we only need to finish the job in GameMaker: Studio. The first thing we need to do is to go to the Global Game Settings -> Android/Fire -> Social. Here you should check the checkbox with “Enable Push Notifications”. Immediately below it, you will see “GCM Sender ID”. Here you should enter the Sender ID of the project you have created in Firebase (recall the end of chapter 2 in case you forgot). We will now follow the same route as in chapter 1 about the local push notifications, however, it’s actually easier now. Let’s create a script called send_push_notification. Put the following code into it. Code: ///send_push_notification() // // Script: Sends a remote push notification to all other users // Date: 2018-07-28 // Copyright: Appsurd var data = "reg_id="+string(global.reg_id)+"&hash=1234"; post = http_post_string("http://ftp.tutorialappsurd.altervista.org/PushNotifications/sendpush.php",data); If you want to push a remote notification, simply call send_push_notification(). Don’t forget to change your address/account name (tutorialappsurd in my case) and the map name (PushNotifications in my case) and the secret key (1234 in my case). When executing this script, it sends a request to the PHP file on Altervista which on his turn finds all registration IDs and sends the request to the GCM server. Now we need something in-game to handle the data send. We will use almost the same code as in chapter 1. Now put the following code in the Create Event of the first object in your game. Please note that this object should be persistent and always present. This ensures that it won’t miss the return from the GCM server. Code: /// Initialise register_id post = -1; ini_open("File.ini"); global.reg_id = ini_read_string("Reg","Reg",""); ini_close(); And this code in the Asynchronous Push Event. Code: /// Handle the data of the push notification var type = ds_map_find_value(async_load, "type"); var status = ds_map_find_value(async_load, "status"); if status == 0 { //error of some kind var error = ds_map_find_value(async_load, "error"); show_message_async("Error:#" + string(error)); } else { // registering for the first time (this is always called at the startup of the app) if type == "register" { var reg_id = ds_map_find_value(async_load, "reg_id"); // If the player's hasn't registered before, add reg_id to the database on Altervista if reg_id != global.reg_id { global.reg_id = reg_id; ini_open("File.ini"); ini_write_string("Reg","Reg",global.reg_id); ini_close(); var data = "reg_id="+string(global.reg_id)+"&hash=1234"; // Fill in your own hash (1234) post = http_post_string("http://ftp.tutorialappsurd.altervista.org/PushNotifications/addpush.php",data); // Fill in your own account name (tutorialappsurd) and map name (PushNotifications) here show_message_async("New register ID:#"+string(global.reg_id)); } else { show_message_async("Old register ID:#"+string(global.reg_id)); } } else // show the data received { var data = ds_map_find_value(async_load, "data"); show_message_async("Data:#"+string(data)); } } Just in case you forgot, please place this script in the Asynchronous Push Notification Event in an object which is persistent and which is present from the very beginning of your game. The time it takes for the event to trigger varies from a couple of milliseconds to a few seconds, so it is very important to put it into the right place to prevent all kinds of trouble! Also, don’t forget to change the directory and table name in the code above in the http_post_string function! We are almost done by now! The only thing we still haven’t done is adding the Google Play Services extension to the project. Open up the Marketplace and download the Google Player Services extension from https://marketplace.yoyogames.com/assets/2008/google-play-services and add it to your project. That’s it! You are done by now and know now how you can use push notifications in your own app! Perhaps not everything is too clear yet for you, so I created an example in which all code is used which I discussed in this tutorial. You can download the project in the Marketplace: https://marketplace.yoyogames.com/assets/4818/push-notifications-example. You may copy the code to use in your own projects, but please do not sell it under your own name. Please note that you cannot compile the code given in the example since I used a different secret key. In my previous tutorial, I noticed that many users (accidently) screwed up the highscore table and I don’t want that to happen in this tutorial too, so I hope you can forgive me Conclusion The tutorial is finished by now, I hope you have learned how you can create your own push notifications in GameMaker: Studio. We saw that local push notifications barely cost any time, but remote push notifications required much more work but the result is very awesome. If there are any questions or if you find anything unclear, please post your response in the comments below. Thanks for reading the tutorial and have fun with your push notifications! Error solving: 401 unauthorised Sometimes the GCM server returns a “401 Unauthorised Error”. I am not completely aware of what is going wrong. Mostly this is due to sending the GCM a registration ID which is not known by GCM. This could happen if the player has deleted your app or something got messed up in the Altervista database which yields incorrect registration IDs. I first recommend to empty the database. Thereafter carefully check if the PHP files and your GameMaker: Studio setup is the same as described in the tutorial. Whenever you are still experiencing the problem, you may try to create a new project in Firebase. If it still doesn’t work, I’m afraid I can’t help you out and I would love to hear from you when you found a solution. Note that if you are accidently using the old version of Google Cloud Messaging, the message “401 Unauthorised Error” will be shown every single time. So DO NOT use the old version! Changelog Changelog, huh? Yes, it’s actually just for me to check when and what I changed in the tutorial. Any people contributing something will be added too. V1.0.3 (2018-08-09) - New screenshots since Firebase looks a little different - Small text fixes V1.0.2 (2018-04-08) - Removed APK as it was not used by many - Small text fixes V1.0.1 (2017-07-24) - Fix: You require the Google Play Services asset for local notifications - Fix: PHP send script only took one value instead of all - Text fixes V1.0.0 (2016-11-28) First English version of the tutorial was written.
i have been looking for these answers for so long, i mean months and months. i will read it over and over then get back to you with the results (well, i guess some questions will come first) THANK YOU! @PeliStar
Would be wonderful a demonstrative video of how to do, although it is a great tutorial has a lot that went unnoticed, For example, Altervista did not work in Brazil, so I went to hostinger and got lost, but I had already lost before hehe
Thanks for your reply! I understand that a video could be really useful, but I don't feel very comfortable creating a video... So I'm afraid you will have to read through the tutorial And I didn't know Altervista doesn't work in Brazil, could you please explain why it doesn't work? If possible, could you add a screenshot? And getting lost in this tutorial isn't too bad, I wrote it for more advanced GameMaker users, so don't expect to be able to follow this when you've just started to use GameMaker: Studio.
Thanks for trying out the tutorial! It's a shame you couldn't make it work, could you please explain where you think it is going wrong? Did you follow the tutorial step-by-step and you are therefore sure you didn't miss out on a step? In case you're not sure, please double check that first It's very difficult for me to understand what's going wrong because I can't look into your project.
Thanks for this, helped a lot. I got it working, (had to change some php as it was only getting the first entry it found.) I wanna make a multiplayer game now... Lots of work ahead, but lots behind me now thanks to your tutorial
Changelog V1.0.1 (2017-07-24) - Fix: You require the Google Play Services asset for local notifications - Fix: PHP send script only took one value instead of all - Text fixes Download the example now for free from the Marketplace: https://marketplace.yoyogames.com/assets/4818/push-notifications-example
Very detailed tutorial. Indeed the level is advanced but if follow whatever that's written closely, you won't go wrong. The author was also helpful and patient in solving an issue as I was not familiar with "server" and "php" jargons.
Thanks very much! If you have some spare time, could you please rate the asset as well in the Marketplace? Thanks in advance!
Sure, I do! Your tutorial saved countless hours of research and testing. How can I not have spare time for that? I really appreciate this! Don't mention it, I should be thanking you
ok thanks for the turtial i did as u saed but you did't mention how to send the remote push notifications to user device
I'm pretty sure I did Please take a little more time to read through the tutorial more carefully. Perhaps try to copy it along while you read, usually that really helps to understand what is going on. Good luck and if you have any questions regarding a specific problem, please post it here!
while to be honest i readed one more time i really don't see where you saed how to send a message to user using remote push notifaction can u give a hint
Certainly. In Chapter 3, we create PHP scripts in Altervista. From GameMaker (as explained in Chapter 4), you call these PHP files. Then the PHP files make a submission to GCM (Google Cloud Messaging) which sends the correct push notification to the right user. That's the general idea.
Hi , cant we send Notifications to our app users using firebase anymore ? , everything is correct ( google play service extension , the values ( ntf_title ... ) , the id , the package name ... ) but the app still dont recieve anything ! it was working before .. please help
Hi, that's strange indeed! What bothers me the most is that it worked before. Are you certain you did not change anything in the meantime? And what kind of response does it give when you call it? A 401 error?
Changelog V1.0.2 (2018-04-08) - Removed APK as it was not used by many - Small text fixes Download the example now for free from the Marketplace: https://marketplace.yoyogames.com/assets/4818/push-notifications-example
