CRNS-32: Handling channel.truncated event

Author: vishalnarkhede

src/components/ChannelList.js

@@ -76,6 +76,13 @@ const ChannelList = withChatContext(
        * @param {Event} event       [Event object](https://getstream.io/chat/docs/#event_object) corresponding to `channel.updated` event
        * */
       onChannelUpdated: PropTypes.func,
+      /**
+       * Function to customize behaviour when channel gets truncated
+       *
+       * @param {Component} thisArg Reference to ChannelList component
+       * @param {Event} event       [Event object](https://getstream.io/chat/docs/#event_object) corresponding to `channel.truncated` event
+       * */
+      onChannelTruncated: PropTypes.func,
       /**
        * Function that overrides default behaviour when channel gets deleted. In absence of this prop, channel will be removed from the list.
        *
@@ -108,6 +115,10 @@ const ChannelList = withChatContext(
        * @param channel A Channel object
        */
       setActiveChannel: PropTypes.func,
+      /**
+       * If true, channels won't be dynamically sorted by most recent message.
+       */
+      lockChannelOrder: PropTypes.bool,
     };
 
     static defaultProps = {
@@ -121,6 +132,7 @@ const ChannelList = withChatContext(
       sort: {},
       // https://github.com/facebook/react-native/blob/a7a7970e543959e9db5281914d5f132beb01db8d/Libraries/Lists/VirtualizedList.js#L466
       loadMoreThreshold: 2,
+      lockChannelOrder: false,
       logger: () => {},
     };
 
@@ -301,7 +313,7 @@ const ChannelList = withChatContext(
       }
 
       if (e.type === 'message.new') {
-        this.moveChannelUp(e.cid);
+        !this.props.lockChannelOrder && this.moveChannelUp(e.cid);
       }
 
       // make sure to re-render the channel list after connection is recovered
@@ -416,6 +428,18 @@ const ChannelList = withChatContext(
         }
       }
 
+      if (e.type === 'channel.truncated') {
+        this.setState((prevState) => ({
+          channels: [...prevState.channels],
+        }));
+
+        if (
+          this.props.onChannelTruncated &&
+          typeof this.props.onChannelTruncated === 'function'
+        )
+          this.props.onChannelTruncated(this, e);
+      }
+
       return null;
     };