Firebase 网络应用聊天重复聊天输入

Question

您好，我是 firebase 的新手，正在尝试开发一个聊天应用程序，对于聊天消息的处理，一切看起来都不错，只是它会在用户切换到 pm 另一个用户时立即复制发件人面板上的数据，并且在他/她回到前一个用户之后，它也复制了那个人的聊天..虽然它没有存储在 Firebase 数据库中，这也很奇怪.. 重复从 1 开始，然后如果用户增加，它会增加再次切换到其他用户

这是聊天应用程序的整个 firebase 代码，这是状态和聊天教程的组合

   // Reference for tbl message
  var messagesRef = new Firebase('https://url-for-tablemessage');


  // Reference for tbl userprofile
  var userListRef = new Firebase("https://url-for-userprofile");


  var myUser = userListRef.child(idf);
  // Get a reference to my own presence status.
  var connectedRef = new Firebase("https://url-for-userprofile//.info/connected");

 function getmsg(){
            // Loads Previous Message with the selected user/s.
     messageList.html("");
     messagesRef.limit(10).on('child_added', function (snapshot) {
           //GET DATA
           var data = snapshot.val(), username = data.name, message = data.text,
               sendr = data.sender, recievr = data.reciever, ui =  $('#chat-avatar').attr("data-ui"),
               style_c = "";

 if (username != nameField){ style_c = "message chat";}
             else{ style_c = "message user";  }

                    var messageElement = $('<div class="'+style_c+'"><div class="message-info">'+
             '<img width="40" height="40" src="temp/user/'+username+'.jpg">' +
                 '<div class="message-timestamp">' +
                 ' <time datetime="" class="timeago uk-text-small">09:22 am</time>' +
                 '</div></div>' +
               ' <div class="message-data">' +
               ' <div class="bubble"></div></div></div>');
         if (((idf == sendr) && (ui == recievr) )||((idf == recievr) && (ui == sendr) )){
               messageElement.find('.bubble').html(message).emoji();
               //ADD MESSAGE

               messageList.append(messageElement);}
           //SCROLL TO BOTTOM OF MESSAGE LIST
              messageList[0].scrollTop = messageList[0].scrollHeight;
   });
  }
  // A helper function to let us set our own state.
  function setUserStatus(status) {
    // Set our status in the list of online users.
    currentStatus = status;
    myUser.set({ id:idf, names: name, firstname:fname, lastname:lname, status: status });
  }
  function getMessageId(snapshot) {
    return snapshot.name().replace(/[^a-z0-9\-\_]/gi,'');
  }
  // Update our GUI to show someone"s online status.
  userListRef.on("child_added", function(snapshot) {
    var user = snapshot.val();

  if (user.names != name) {
         $("<a />")
        .attr({"id": getMessageId(snapshot),"data-username":user.names,"data-fname":user.firstname,"data-lname":user.lastname})
        .html(user.names + "<br />")
        .appendTo("#presenceDiv")
        .click(function(){
           var dt = $(this).attr("data-username"),df=$(this).attr("data-fname"),dl=$(this).attr("data-lname"),
               src="temp/user/"+dt+".jpg";
               $('#chat-avatar').show();
           $('#chat-avatar').attr({'src':src,"data-os":user.status,"data-ui":user.id})
           $('#chat-name').html(df + " " + dl);
           console.log(dt);
         messageList.html(""); 
         getmsg();
    });
        $("<li />")
        .attr({"id": getMessageId(snapshot),"data-username":user.names,"class":"offcanvas-chat-avatar","data-fname":user.firstname,"data-lname":user.lastname})
        .html("<small id='ofstat' data-os="+user.status+" data-ui="+user.id+" ></small><img width='40' height='40' src='temp/user/"+user.names+".jpg'>"+ user.names )
        .appendTo("#clist")
        .click(function(){
                  var dt = $(this).attr("data-username"),df=$(this).attr("data-fname"),dl=$(this).attr("data-lname"),
               src="temp/user/"+dt+".jpg";
                  $('#chat-avatar').show();
           $('#chat-avatar').attr({'src':src,"data-os":user.status,"data-ui":user.id});
           $('#chat-name').html(df + " " + dl);
           console.log(dt);
           messageList.html(""); 
           getmsg();

    });


    }

  });




  // LISTEN FOR KEYPRESS EVENT
  messageField.keypress(function (e) {
    if (e.keyCode == 13) {
      //FIELD VALUES
  //messageList.html(""); 
      var username = nameField;
      var message = messageField.val();
      var ui =  $('#chat-avatar').attr("data-ui");
  if(message != ""){
      //SAVE DATA TO FIREBASE AND EMPTY FIELD

      messagesRef.push({name:username, text:message, sender:idf, reciever:ui});

      }else{
      alert("Text Field Empty");
      }
      //getmsg();

      messageField.val('');

      e.preventDefault();
      // return false;
    } 
  });

我真的需要这个才能继续工作.. 被困在这里将近 3 周了，因此我不确定我所做的是否真的正确，但我可以说的是我认为错误在于getmsg() 函数虽然不确定...请帮助我:(

Answer 1

当消息来自当前经过身份验证的用户时，您是否尝试以不同的方式格式化消息？这就是调用 getMsg() 的原因吗？

我将为您提供另一种思考方式，因为这是我设法做到的，而且我没有这个错误。我认为你的错误来自这样一个事实，即无论你是否调用 getMsg()，都可能调用 .on('child_added')。

我的解决方案涉及以下内容

messagesRef.limit(msgLimit).on('child_added', function (snapshot) {
        var message = snapshot.val();

        //format timestamp from linux epoch to readable format
        var ts = getTimestamp(message.timestamp);

        //gets the image from the user who sent the message
        var userImg = userSnapshot.child(message.userID).child('img').val();

        //variables for message layout
        var chatMsgImg = $('<img>',{class:'avatar', src:userImg});
        var chatMsgDiv = $('<div/>',{class:'message'});
        var chatMsgArrow = $('<span/>', {class:'arrow'});
        var chatMsgName = $('<span/>', {class:'name'}).text(message.from);
        var chatMsgTimestamp = $('<span/>', {class:'datetime'}).text(' '+ts);
        var chatMsgContent = $('<span/>', {class:'body'}).text(message.text);

        //if the message is from the currently signed in user, then align right and use class out
        if((message.userID) == userID){
            var msg = $('<li/>', {class:'out'});
            msg.append(chatMsgImg);
            chatMsgDiv.append(chatMsgArrow);
            chatMsgDiv.append(chatMsgName);
            chatMsgDiv.append(chatMsgTimestamp);
            chatMsgDiv.append(chatMsgContent);
            msg.append(chatMsgDiv);
            msg.appendTo($('#chatDiv'));
        }
        //otherwise align left and use class in
        else{
            var msg = $('<li/>', {class:'in'});
            msg.append(chatMsgImg);
            chatMsgDiv.append(chatMsgArrow);
            chatMsgDiv.append(chatMsgName);
            chatMsgDiv.append(chatMsgTimestamp);
            chatMsgDiv.append(chatMsgContent);
            msg.append(chatMsgDiv);
            msg.appendTo($('#chatDiv'));
        }

        $('#chatDiv')[0].scrollTop = $('#chatDiv')[0].scrollHeight;
    });

通过这种方式，我仍然可以获得相同的消息详细信息，但我将格式留给 CSS，只使用输入和输出或传入和传出消息（分别来自其他用户和来自当前用户）