How to display a please wait message when the server is processing using addBusyStateListener in ADF ? https://cedricleruth.com/how-to-display-a-please-wait-message-when-the-server-is-processing-using-addbusystatelistener-in-adf/

warnAndPreventUserInputADF.js

var popup = null;
var clickedElem = null;

function triggerOnLoad(event) {
    //You can either set the popup using the pure html div id (recommended)
    popup = AdfPage.PAGE.findComponentByAbsoluteId(document.getElementById('loaderId').nextSibling.id);
    //or set the popup knowing the full id of your popup for example :
    //popup = AdfPage.PAGE.findComponentByAbsoluteId('p1:processingP');
    //popup = AdfPage.PAGE.findComponent('processingP');
    return true;
}

function warnAndPreventUserInput(evt) {
    //To avoid most mistake where addBusyStateListener and removeBusyStateListener don't have the same arguments
    //You can set the element to listen for the application busy state to be the one the user just clicked : 
    clickedElem = evt.getSource();
    if (popup != null) {
        //Adds a listener to call the handleBusyState function whenever there is a busy state event.
        AdfPage.PAGE.addBusyStateListener(clickedElem, handleBusyState);
        //Don't authorize the user to interact with ADF while it's busy
        evt.preventUserInput();
    } else {
        console.error('The processing pop up isnt defined on this page ');
    }
}

//JavaScript call back handler
function handleBusyState(evt) {
    if (popup != null) {
        if (evt.isBusy()) {
            //Processing in progress so we display the popup
            popup.show();
        } else {
            //Processing is done so we can close the popup
            popup.hide();
            //Important : We remove the listener from the clicked object so it will 
            //stop looking for a busy event to display the popup
            AdfPage.PAGE.removeBusyStateListener(clickedElem, handleBusyState);
        }
    } else {
        console.error('The processing pop up isnt defined on this page ');
    }
}