Merge pull request #50 from alexislefebvre/readme-explain-channel-name

README: Explain channel name

README.md

@@ -14,26 +14,72 @@ Server-side library for working with Expo push notifications using PHP
 
         require_once __DIR__.'/vendor/autoload.php';
 
-        $interestDetails = ['unique identifier', 'ExponentPushToken[unique]'];
+        $channelName = 'news';
+        $recipient= 'ExponentPushToken[unique]';
 
         // You can quickly bootup an expo instance
         $expo = \ExponentPhpSDK\Expo::normalSetup();
 
         // Subscribe the recipient to the server
-        $expo->subscribe($interestDetails[0], $interestDetails[1]);
+        $expo->subscribe($channelName, $recipient);
 
         // Build the notification data
         $notification = ['body' => 'Hello World!'];
 
         // Notify an interest with a notification
-        $expo->notify($interestDetails[0], $notification);
+        $expo->notify($channelName, $notification);
 
 Data can be added to notifications by providing it as a JSON object. For example
 
 
         // Build the notification data
         $notification = ['body' => 'Hello World!', 'data'=> json_encode(array('someData' => 'goes here'))];
 
+# Channel name
+
+You can use channels to send a notification to only one user, or to a group of users:
+
+## One recipient
+
+In order to target one recipient (and avoid sending a notification to the wrong recipient), use a channel name specific to each user:
+
+```php
+$channelName = 'user_528491';
+$recipient = 'ExponentPushToken[unique]';
+
+// …
+
+// Subscribe the recipient to the server
+$expo->subscribe($channelName, $recipient);
+
+// …
+
+// Notify an interest with a notification, only one recipient will receive it
+$expo->notify($channelName, $notification);
+```
+
+## Several recipients
+
+Declare a channel name that will be shared between the recipients:
+
+```php
+$channelName = 'group_4815';
+
+$recipient1 = 'ExponentPushToken[unique1]';
+$recipient2 = 'ExponentPushToken[unique2]';
+
+// …
+
+// Subscribe the recipients to the server
+$expo->subscribe($channelName, $recipient1);
+$expo->subscribe($channelName, $recipient2);
+
+// …
+
+// Notify an interest with a notification, the 2 recipients will receive it
+$expo->notify($channelName, $notification);
+```
+
 # TODO
 - Need to create tests