Question

I am creating a basic Php Ajax chat application.

when i am using this basic application on my own PC in cross browser(means in one time chrome and Mozilla assuming two person) is working fine. but when i am using this application on cross PC means one man is chatting from one PC and another man is chatting from 2nd PC then it is not working..

Problem : send chat content from one PC is receiving on 2nd pc
but from second PC (chat Reply) send chat content is not receiving

 Ajax response is not coming using `set Interval` and browser is not refreshing..

Code :

J query

setInterval(function() { 
   $.ajax({
     url: "http://192.168.1.13/naresh/ajaxchat/chatsave.php?q=getChat",
     success: function(response) {
        $("#ulShowChatContent").append(response);
         }
    });
}, 1000);

Php

function getChat(){
        $useremail  = $_SESSION['email'];
        $sqlGetUserInfo = mysql_query("select * from  users where email = '$useremail'") or die(mysql_error());
        if(mysql_num_rows($sqlGetUserInfo)>0){
            $userInfo = mysql_fetch_array($sqlGetUserInfo);
            $userId = $userInfo['id']; 
            $currentdate =  date('Y-m-d H:i:s');

            $sqlGetChatContent = mysql_query("select chat_id,chat_content,name from pvt_chat 
                                                INNER JOIN users ON pvt_chat.userid = users.id 
                                                where pvt_chat.userid != '$userId' 
                                                and receive_status = 0
                                                and send_datetime <= '$currentdate' 
                                                ORDER BY send_datetime DESC limit 1") or die(mysql_error());

            if(mysql_num_rows($sqlGetChatContent)>0) {
                $resGetChatContent = mysql_fetch_array($sqlGetChatContent);
                $receiveChatId = $resGetChatContent['chat_id'];
                echo '<li>'.$resGetChatContent['name'].' says : '.$resGetChatContent['chat_content'].'</li>';
                $sqlUpdateRecStatus = mysql_query("UPDATE pvt_chat SET receive_status = '1' WHERE chat_id ='$receiveChatId'") or die(mysql_error());
            }
        }
    }

Answer 1

My question to you: what web page (+ domain) is PC2 using to access the chat? If the page is accessed from his localhost or any domain/IP other than 192.168.1.13 you have a cross-domain issue.
Browsers today block AJAX calls to webpages on another domain (and even subdomain and port has to be the same IIRC) for security reasons. If PC2 is accessing the webpage from http://localhost/chatPage.html (for example), then he cannot make a request to “http://192.168.1.13” in the AJAX call.

Some solutions:

• Host the chatpage on the same server as where your AJAX calls are originated from (so that the domain of the chatpage is the same as the domain of the AJAX call)
• Use a JSON response and convert it to HTML in the browser. There is a workaround for cross-domain issues when you’re using JSON, but that means that you have to convert the JSON output to HTML by yourself. You also need to make sure that you put the attribute dataType: 'jsonp' in your AJAX call.