Chat.tsx - Load Messages - Ionic Chat App

Chat.tsx

...
const Chat: React.FC = () => {
  const history = useHistory();

  const { cometChat, user, selectedConversation, setCallType } = useContext(Context);

  const [messages, setMessages] = useState<any>([]);
  ...
  const messageRef = useRef<any>(null);
  const messageBottomRef = useRef<any>(null);
  ...
  useEffect(() => {
    if (selectedConversation) {
      // get list of messages.
      getMessages();
      ...
    }
    ...
  }, [selectedConversation]);

  useEffect(() => {
    if (messages && messages.length !== 0) {
      // scroll to bottom.
      scrollToBottom();
    }
  }, [messages]);
  ...

  const scrollToBottom = () => {
    if (messageBottomRef && messageBottomRef.current) {
      messageBottomRef.current.parentNode.scrollTop = messageBottomRef.current.offsetTop;
    }
  }
  ...  

  const getContentMessage = (message: any) => {
    if (message) {
      return message.text ? message.text : message.data && message.data.url ? message.data.url : null;
    }
    return null;
  };

  const transformMessages = (messages: any) => {
    if (messages && messages.length !== 0) {
      const transformedMessages = [];
      for (const message of messages) {
        const messageContent = getContentMessage(message);
        if (messageContent) {
          transformedMessages.push({
            id: message.id,
            text: messageContent,
            receiverId: message.receiverId,
            sender: {
              uid: message.sender.uid,
              avatar: message.sender.avatar ? message.sender.avatar : user.avatar
            },
            type: message.type,
            deliveredAt: message.deliveredAt,
            readAt: message.readAt
          });
        }
      }
      return transformedMessages;
    }
    return messages;
  };

  const getReceiverIdForMarkingAsRead = (message: any) => {
    if (message.receiverType === cometChat.RECEIVER_TYPE.USER) {
      return message.sender.uid;
    }
    return message.receiverId;
  };

  const sendReadBulkReceipts = (messages: any) => {
    if (messages && messages.length !== 0) {
      // get the last message.
      const lastMessage = messages[messages.length - 1];
      const receiverId = getReceiverIdForMarkingAsRead(lastMessage);
      cometChat.markAsRead(lastMessage.id, receiverId, lastMessage.receiverType, lastMessage.sender.uid).then();
    }
  };

  const getMessages = () => {
    const limit = 50;
    const messageRequestBuilder = new cometChat.MessagesRequestBuilder()
      .setCategories(["message"])
      .setLimit(limit)
    if (selectedConversation.contactType === 1) {
      messageRequestBuilder.setGUID(selectedConversation.guid);
    } else if (selectedConversation.contactType === 0) {
      messageRequestBuilder.setUID(selectedConversation.uid);
    }

    const messagesRequest = messageRequestBuilder.build();

    messagesRequest
      .fetchPrevious()
      .then((messages: any) => {
        setMessages(() => transformMessages(messages));
        sendReadBulkReceipts(messages);
        scrollToBottom();
      })
      .catch((error: any) => { });
  }

  const getReceiverId = () => {
    if (selectedConversation && selectedConversation.guid) {
      return selectedConversation.guid;
    }
    if (selectedConversation && selectedConversation.uid) {
      return selectedConversation.uid;
    }
    return null;
  };

  const getReceiverType = () => {
    if (selectedConversation && selectedConversation.guid) {
      return cometChat.RECEIVER_TYPE.GROUP;
    }
    return cometChat.RECEIVER_TYPE.USER;
  };
  ...

  const sendMessage = (e: any) => {
    if (e.key === 'Enter') {
      // get the value from input.
      const message = messageRef.current.value;
      if (message) {
        // call cometchat api to send the message.
        const textMessage = new cometChat.TextMessage(
          selectedConversation.contactType === 0 ? selectedConversation.uid : selectedConversation.guid,
          message,
          selectedConversation.contactType === 0 ? cometChat.RECEIVER_TYPE.USER : cometChat.RECEIVER_TYPE.GROUP
        );

        cometChat.sendMessage(textMessage).then(
          (msg: any) => {
            // reset input box.
            messageRef.current.value = '';
            // append the new message to "messages" state.
            setMessages((prevMessages: any) => [...prevMessages, {
              id: uuidv4(),
              text: message,
              receiverId: getReceiverId(),
              sender: {
                uid: user.uid,
                avatar: user.avatar
              },
              isRight: true
            }]);
            // scroll to bottom.
            scrollToBottom();
            // send end typing notification.
            sendEndTypingNotification();
          },
          (error: any) => {
            alert('Cannot send you message, please try later');
          }
        );
      }
    }
  }

  const isRight = (message: any) => {
    if (message.isRight !== null && message.isRight !== undefined) {
      return message.isRight;
    }
    return message.sender.uid === user.uid;
  }
  ...

  if (!selectedConversation) {
    history.push('/');
  }
  ...

  return (
    <>
      <IonHeader>
        <IonToolbar>
          <IonButtons slot="start">
            <IonBackButton defaultHref="/" />
          </IonButtons>
          <IonButtons slot="end">
            <IonButton onClick={startAudioCall}>
              <IonIcon slot="icon-only" icon={callOutline} />
            </IonButton>
          </IonButtons>
          <IonButtons slot="end">
            <IonButton onClick={startVideoCall}>
              <IonIcon slot="icon-only" icon={videocamOutline} />
            </IonButton>
          </IonButtons>
          {selectedConversation && selectedConversation.contactType === 1 && <IonButtons slot="end">
            <IonButton onClick={goToManageGroup} >
              <IonIcon slot="icon-only" icon={settings} />
            </IonButton>
          </IonButtons>}
          <div className='chatbox__title'>
            <div className='chatbox__title-avatar-container'>
              <img src={selectedConversation?.avatar ? selectedConversation?.avatar : selectedConversation?.icon ? selectedConversation?.icon : ''} alt={selectedConversation?.name} />
              {selectedConversation && selectedConversation.contactType === 0 && <span className={`chatbox__title-status ${isUserOnline ? 'chatbox__title-status--online' : 'chatbox__title-status--offline'}`}></span>}
            </div>
            <span>{selectedConversation?.name}</span>
          </div>
        </IonToolbar>
      </IonHeader>
      <div className="chatbox">
        <div className="message__container">
          {messages && messages.length !== 0 && messages.map((message: any) => (
            <Message key={message.id} message={message.text} messageType={message.type} deliveredAt={message.deliveredAt} readAt={message.readAt} senderId={message.sender.uid} avatar={message.sender.avatar} isRight={isRight(message)} />
          ))}
          <div ref={messageBottomRef} id="message-bottom"></div>
        </div>
        <div className="chatbox__input">
          <span ref={typingRef} className='hide'>Someone is typing...</span>
          <div>
            <img src={imageIcon} alt='file-chooser' className='chatbox__file-chooser' onClick={toggleActionsSheet(true)} />
            <input type="url" placeholder="Message..." onKeyDown={sendMessage} ref={messageRef} onChange={onInputChanged} onBlur={onInputBlured} />
            <svg fill="#2563EB" className="crt8y2ji" width="20px" height="20px" viewBox="0 0 24 24"><path d="M16.6915026,12.4744748 L3.50612381,13.2599618 C3.19218622,13.2599618 3.03521743,13.4170592 3.03521743,13.5741566 L1.15159189,20.0151496 C0.8376543,20.8006365 0.99,21.89 1.77946707,22.52 C2.41,22.99 3.50612381,23.1 4.13399899,22.8429026 L21.714504,14.0454487 C22.6563168,13.5741566 23.1272231,12.6315722 22.9702544,11.6889879 C22.8132856,11.0605983 22.3423792,10.4322088 21.714504,10.118014 L4.13399899,1.16346272 C3.34915502,0.9 2.40734225,1.00636533 1.77946707,1.4776575 C0.994623095,2.10604706 0.8376543,3.0486314 1.15159189,3.99121575 L3.03521743,10.4322088 C3.03521743,10.5893061 3.34915502,10.7464035 3.50612381,10.7464035 L16.6915026,11.5318905 C16.6915026,11.5318905 17.1624089,11.5318905 17.1624089,12.0031827 C17.1624089,12.4744748 16.6915026,12.4744748 16.6915026,12.4744748 Z" fillRule="evenodd" stroke="none"></path></svg>
          </div>
        </div>
      </div>
      ...
    </>
  );
};
...