Prevent duplicate toast display in EJ2 JavaScript Toast control

10 May 20234 minutes to read

You can prevent identical same toast displaying in a screen by the event function and terminate the toast displaying process by setting the cancel event property in the beforeOpen event.

The following sample demonstrates preventing duplicate title toast element displaying with custom code blocks.

index.js
index.html
ej.base.enableRipple(true);

//Initialize Toast component
var toasts = [
    { title: 'Warning !', content: 'There was a problem with your network connection.', isOpen: false},
    { title: 'Success !', content: 'Your message has been sent successfully.', isOpen: false },
    { title: 'Error !', content: 'A problem has been occurred while submitting your data.', isOpen: false }
];
var toastFlag = 0;

var toast = new ej.notifications.Toast({
    position: {
        X: 'Center'
    },
    beforeOpen: onBeforeOpen,
    close: onClose,
    created: onCreate
});
//Render initialized Toast component
toast.appendTo('#element');
toast.show(toasts[toastFlag]);
++toastFlag;

document.getElementById('show_toast').onclick = function () {
  toast.show(toasts[toastFlag]);
  ++toastFlag;
  if (toastFlag === (toasts.length)) {
      toastFlag = 0;
  }
};

function onClose(e) {
  for (var i= 0; i < toasts.length; i++) {
    if (toasts[i].title === e.options.title) {
        toasts[i].isOpen = false;
    }
  }
}

function onCreate(e) {
    toast.show(toasts[toastFlag]);
    ++toastFlag;
}

function onBeforeOpen(e) {
    if (preventDuplicate(e)) {
        e.cancel = true;
	}
}

function preventDuplicate(e) {
    for (var i = 0; i < toasts.length; i++) {
      if (toasts[i].title === e.options.title && !toasts[i].isOpen) {
       toasts[i].isOpen = true;
        return false;
      }
    }
    return true;
}
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 Toast</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Typescript Toolbar Controls">
    <meta name="author" content="Syncfusion">
    <link href="index.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div class="row"> <button class="e-btn" id="show_toast"> Show Toast</button> </div>
        <div id="element"></div>
        <br><br>
        <div id="result"></div>
        <div id="templateToast" style="display: none;color:red"> System affected by virus !!! </div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>