How to competently organize a page refresh to send a request?

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daminik002016-06-19 02:12:16

PHP

daminik00, 2016-06-19 02:12:16

There is a page on which, using php, a code is written that checks the last message in VK and responds to it under certain conditions. What is the best way to organize a page update, since the code only works when the page is updated. It is necessary that the site is somehow updated in the background if a new message arrives. The main thing is that there would not be a large load on the server. You can not paint the solution completely, but simply direct it in the right direction. Thank you very much in advance)

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3 answer(s)

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Daemon23RUS, 2016-06-19
@Daemon23RUS

Fragment HTML

<body onload="(function() {getVSD();window.setInterval(getVSD, 3000)})()">

In addition to it, a function in Java

function getVSD(){			//Get Status of Servers
  var xmlhttp = getXmlHttp();
  xmlhttp.open('GET', 'status.php', true);

  xmlhttp.onreadystatechange = function() {
    if (xmlhttp.readyState == 4) {
      if(xmlhttp.status == 200) {
        var response = JSON.parse(xmlhttp.responseText);
        response.forEach(function(item){loadContent(item.element,item.status);});
      } else {GLOBAL_STATUS.forEach(function(item){loadContent(item.element,item.status);});}
    };}
  xmlhttp.send(null);
}

If my memory serves me, then this bundle will poll status.php once every 3 seconds. This is a fragment from a working project, so finish it for yourself ..
In my case, with a successful request ( if(xmlhttp.status == 200)), the corresponding info on the page changes without reloading the page as such.

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Rou1997, 2016-06-19
@Rou1997

To get a message from the server without refreshing the page, it's enough to make an AJAX request (HTTP request using JavaScript), you can start with jQuery or from here , but in your case you will have to send requests very often, this is a big load on both the client and the server, you can use long polling instead of frequent, but WebSockets is better, it's almost "raw" TCP / IP, unlike HTTP, you don't have to send requests (packets) at all, so there will be no load on the client and server until the server itself sends a message .

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profesor08, 2016-06-19
@profesor08

Try using a widget. Or are there none?