It took me some time to check how GCM works. See Erels example: https://www.b4x.com/android/forum/t...ion-gcm-framework-and-tutorial.19226/#content
A lot of excellent stuff but sometimes too much for a quick try. So here I would like to do a summary with more explanations and how it works.
Let's take a look at WhatsApp. If you get a message you get notified about it. The developers of the app could check the server's databases every second if there's a new message for you. This would cause about 1 billion apps to make db requests every second which will cause very big troubles. The servers would be killed due to traffic.
Checking all users if a new message has arrived makes no sence, too because - let's say in a minute - only "50.000" users send messages. So it would be better to notify just those 50K.
As the creator of WhatsApp you then have to think about how to reach a user (app) when a message has arrives for him/her. That's the moment when Google does the trick. They offer a api to send some sort of a ping to the device (phone/tablet, etc.) to say "hey, there is a message".
As there are several apps on your device which need to receive "notifications" (e.g. WhatsApp, Facebook, GMail, etc.) each app has to register itsself to the Google api for a sender.
So what is a "sender" and how is it named?
Get to https://console.cloud.google.com and login with your developer account. Here you can create a new project (see Erel's example above how to do that). When the project is created, you get a project number. And this is the sender-id (12 digits like 123456789012)
Register the app
See Erel's example code (device). Open it in B4a. In "Main/Process_Globals" you find:
Change "123456789012" to the one you get from Google (project-number/id).
Start it. In "RegisterDevice" the device will be registered to the project number (Google services are called). In "HandleRegistrationResult" Google get's back and answeres with a registration id. This long string is the unique key for the device registered to the sender. 10 devices will have 10 different id's
In debug just copy the content of "rid" to the clipboard. It looks like:
How do we send a notification/message to the device?
This is a server thing as this is not about sending messages like a WhatsApp massage. It's a server message from the sender to the device (ID) that there IS something to do. Of course (like WhatsAPP) we can send some additional data, too (e.g. to show the first line of the real message for a notification).
Erel uses a php-script to do that (this of course a similar one)
Replace "'AI*********************'" with your own key of the project. That's it!
To send a message from a browser just call it (I've put it in a folder called "GCM"):
APA91bHX8sFyx413fEDhL8e696zWe -> this is the key from above which you copied into the clipboard.
That's all you have to do..
Google returns:
In Erel's app "MessageArrived" will called immediately like magic (take care you didn't stop the debugger). Here you can get the data from the php (e.g. "'message' => 'here is a message. message'"). Inside the code you get it with:
In the php you just can expand the array with other key/value pairs like you want. Very easy.
Summary:
1. Create an new Messaging project
2. Get the project name (12 digits) - sometimes called project id
3. Get the "browser key" (=api access key)
Workflow:
Project name -> put it inside the app as "SenderID"
Access Key -> put it in the php
Run the app -> get the rid (registration id)
Call the php with the rid via HttpUtils or via Browser to send a message
Errors:
- rid correct?
- others: Use Google
As always:
- protect the php and the access key
- use the php code inside your database php's as a function
- store the registration id's in a table with user credentials (phone number?)
- use pw's, etc.
A lot of excellent stuff but sometimes too much for a quick try. So here I would like to do a summary with more explanations and how it works.
Let's take a look at WhatsApp. If you get a message you get notified about it. The developers of the app could check the server's databases every second if there's a new message for you. This would cause about 1 billion apps to make db requests every second which will cause very big troubles. The servers would be killed due to traffic.
Checking all users if a new message has arrived makes no sence, too because - let's say in a minute - only "50.000" users send messages. So it would be better to notify just those 50K.
As the creator of WhatsApp you then have to think about how to reach a user (app) when a message has arrives for him/her. That's the moment when Google does the trick. They offer a api to send some sort of a ping to the device (phone/tablet, etc.) to say "hey, there is a message".
As there are several apps on your device which need to receive "notifications" (e.g. WhatsApp, Facebook, GMail, etc.) each app has to register itsself to the Google api for a sender.
So what is a "sender" and how is it named?
Get to https://console.cloud.google.com and login with your developer account. Here you can create a new project (see Erel's example above how to do that). When the project is created, you get a project number. And this is the sender-id (12 digits like 123456789012)
Register the app
See Erel's example code (device). Open it in B4a. In "Main/Process_Globals" you find:
B4X:
b Process_Globals
Public DeviceBoardPassword, BoardUrl, SenderId, DeviceName As String
DeviceBoardPassword = "********"
BoardUrl = "http://b4aserver******************.php"
'Set this field to match the project ID in Google Console.
SenderId = "123456789012"
End SubChange "123456789012" to the one you get from Google (project-number/id).
Start it. In "RegisterDevice" the device will be registered to the project number (Google services are called). In "HandleRegistrationResult" Google get's back and answeres with a registration id. This long string is the unique key for the device registered to the sender. 10 devices will have 10 different id's
B4X:
...
Else If Intent.HasExtra("registration_id") Then
Dim rid As String
rid = Intent.GetExtra("registration_id")In debug just copy the content of "rid" to the clipboard. It looks like:
B4X:
APA91bHX8sFyx413fEDhL8e696zWeJWivpYB-isYmrJDiU4oBG042-E-SMLwatbc4l*********************************************************************How do we send a notification/message to the device?
This is a server thing as this is not about sending messages like a WhatsApp massage. It's a server message from the sender to the device (ID) that there IS something to do. Of course (like WhatsAPP) we can send some additional data, too (e.g. to show the first line of the real message for a notification).
Erel uses a php-script to do that (this of course a similar one)
B4X:
<?php
// API access key from Google API's Console
define( 'API_ACCESS_KEY', 'AI*********************' );
$registrationIds = array( $_GET['id'] );
// prep the bundle
$msg = array
(
'message' => 'here is a message. message',
'title' => 'This is a title. title',
'subtitle' => 'This is a subtitle. subtitle',
'tickerText' => 'Ticker text here...Ticker text here...Ticker text here',
'vibrate' => 1,
'sound' => 1,
'largeIcon' => 'large_icon',
'smallIcon' => 'small_icon'
);
$fields = array
(
'registration_ids' => $registrationIds,
'data' => $msg
);
$headers = array
(
'Authorization: key=' . API_ACCESS_KEY,
'Content-Type: application/json'
);
$ch = curl_init();
curl_setopt( $ch,CURLOPT_URL, 'https://android.googleapis.com/gcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode( $fields ) );
$result = curl_exec($ch );
curl_close( $ch );
echo $result;Replace "'AI*********************'" with your own key of the project. That's it!
To send a message from a browser just call it (I've put it in a folder called "GCM"):
B4X:
http://yourdomain.com/GCM/gcm.php?id=APA91bHX8sFyx413fEDhL8e696zWeAPA91bHX8sFyx413fEDhL8e696zWe -> this is the key from above which you copied into the clipboard.
That's all you have to do..
Google returns:
B4X:
{"multicast_id":8199xxxxxxxxxxx,"success":1,"failure":0,"canonical_ids":0,"results":[{"message_id":"0:146238xxxxxxxxxxxxxxxxxx"}]}In Erel's app "MessageArrived" will called immediately like magic (take care you didn't stop the debugger). Here you can get the data from the php (e.g. "'message' => 'here is a message. message'"). Inside the code you get it with:
B4X:
If Intent.HasExtra("message") Then Data = Intent.GetExtra("message")In the php you just can expand the array with other key/value pairs like you want. Very easy.
Summary:
1. Create an new Messaging project
2. Get the project name (12 digits) - sometimes called project id
3. Get the "browser key" (=api access key)
Workflow:
Project name -> put it inside the app as "SenderID"
Access Key -> put it in the php
Run the app -> get the rid (registration id)
Call the php with the rid via HttpUtils or via Browser to send a message
Errors:
- rid correct?
- others: Use Google
As always:
- protect the php and the access key
- use the php code inside your database php's as a function
- store the registration id's in a table with user credentials (phone number?)
- use pw's, etc.
