From 8ec52793270ffd2b4c43585b0a3247571650dfcb Mon Sep 17 00:00:00 2001
From: Alec Gibson <12036746+alecgibson@users.noreply.github.com>
Date: Tue, 12 Jul 2022 15:58:35 +0100
Subject: [PATCH] =?UTF-8?q?=F0=9F=93=9D=20Update=20presence=20documentatio?=
 =?UTF-8?q?n?=
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This change updates our presence documentation to highlight that
disconnections can be seen with a `null` value.
---
 docs/api/presence.md |  3 +++
 docs/presence.md     | 16 ++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/docs/api/presence.md b/docs/api/presence.md
index 8d55b04c3..d8768a7a9 100644
--- a/docs/api/presence.md
+++ b/docs/api/presence.md
@@ -143,6 +143,9 @@ presence.on('receive', function(id, value) { ... });
 
 > The presence value. The structure of this object will depend on the [type]({{ site.baseurl }}{% link types/index.md %})
 
+{: .info }
+> A `null` value means the remote client is no longer present in the document (e.g. they disconnected)
+
 ### `'error'`
 
 An error has occurred.
diff --git a/docs/presence.md b/docs/presence.md
index 7555d0994..9567446e2 100644
--- a/docs/presence.md
+++ b/docs/presence.md
@@ -22,6 +22,14 @@ In this case, clients just need to subscribe to a common channel using [`connect
 ```js
 const presence = connection.getPresence('my-channel')
 presence.subscribe()
+
+presence.on('receive', (presenceId, update) => {
+  if (update === null) {
+    // The remote client is no longer present in the document
+  } else {
+    // Handle the new value by updating UI, etc.
+  }
+})
 ```
 
 In order to send presence information to other clients, a [`LocalPresence`]({{ site.baseurl }}{% link api/local-presence.md %}) should be created. The presence object can take any arbitrary value
@@ -51,6 +59,14 @@ Clients subscribe to a particular [`Doc`]({{ site.baseurl }}{% link api/doc.md %
 ```js
 const presence = connection.getDocPresence(collection, id)
 presence.subscribe()
+
+presence.on('receive', (presenceId, update) => {
+  if (update === null) {
+    // The remote client is no longer present in the document
+  } else {
+    // Handle the new value by updating UI, etc.
+  }
+})
 ```
 
 The shape of the presence value will be defined by the [type]({{ site.baseurl }}{% link types/index.md %}):