QueryTask and IdentifyTask replacement in Arcgis version 4.27

[samitalebi]

I'm about to update Arcgis from version 3 to 4.27 but don't have any idea how can I convert the below function:

function InfWindow(point, screenPoint) {
var qtLGA = new esri.tasks.QueryTask(WaterConnectMapServerURL + "/16/");
var qLGA = new esri.tasks.Query();

qtLGA.requestTimeout = 180;
qLGA.requestTimeout = 180;

qLGA.returnGeometry = false;
qLGA.outFields = ["ABBNAME"];
qLGA.geometry = point;
var qLGADefer = qtLGA.execute(qLGA);

var identifyTask = new esri.tasks.IdentifyTask(FloodMapServerURL);
identifyTask.requestTimeout = 180;
var identifyParams = new esri.tasks.IdentifyParameters();
identifyParams.tolerance = 0;
identifyParams.returnGeometry = false;
identifyParams.layerOption = esri.tasks.IdentifyParameters.LAYER_OPTION_ALL;
identifyParams.width = map.width;
identifyParams.height = map.height;
identifyParams.geometry = point;
identifyParams.mapExtent = map.extent;
var identifyDefer = identifyTask.execute(identifyParams);

map.infoWindow.show(screenPoint, map.getInfoWindowAnchor(screenPoint));
map.infoWindow.setTitle("Loading...");
map.infoWindow.setContent("");

var promises = new all([qLGADefer, identifyDefer]);
promises.always(function (results) {
var infContent = [];
infContent.push("<table class='tblInfoWindow'>");
infContent.push("<tr class='tblInfoWindowTrHeader'>");
infContent.push("<th>Study</th>");
infContent.push("<th class='th-Internal-Pad'>Layer</th>");
infContent.push("<th class='th-Internal-Pad'>Depth&nbsp;Range&nbsp;(m)</th>");
infContent.push("</tr>");

for (var i = 0; i < results.length; i++) {
if (results[i].features != null) {
if (jQuery.isEmptyObject(results[i].features)) {
map.infoWindow.setTitle("Outside Local Council Area");
}
else {
map.infoWindow.setTitle(results[i].features[0].attributes.ABBNAME);
}
}

if ($.isArray(results[i])) {
if (results[i].length == 0) {

}
for (var j = 0; j < results[i].length; j++) {
infContent.push("<tr class='tblInfoWindowTrData'>");
infContent.push("<td>" + IDtoLabel[results[i][j].layerId] + "</td>");
infContent.push("<td class='td-Internal-Pad'><a title='Turn on layer' href='javascript&colon;void(0)' class='LayerLink " + results[i][j].layerId + "'>" + results[i][j].layerName + "</a></td>");
if (results[i][j].displayFieldName.toUpperCase().indexOf("RANGE") != -1)
infContent.push("<td class='td-Internal-Pad'>" + results[i][j].value + "</td>");
else
infContent.push("<td class='td-Internal-Pad'>Extent only</td>");
infContent.push("</tr>");
}
}
}
infContent.push("</table>");
map.infoWindow.resize(400, 200);
var infContentJoined = infContent.join('');
if (infContentJoined.indexOf("tblInfoWindowTrData") == -1) {
map.infoWindow.setContent("No study data available at this location. Searching nearby...");
SearchWithTolerance(point);
}
else {
map.infoWindow.setContent(infContentJoined);
$(".tblInfoWindow").find("img.pdfIcon_layer").click(function () {
var layerID = $(this).attr("id").replace("img_layer", "");
OpenPDFLink(layerID);
});
$(".tblInfoWindow").find("img.Question").click(function () {
var layerID = $(this).attr("id").replace("question_layer", "");
var layerName = $.trim($(this).parent().text());
OpenQuestionLink(layerID, layerName);
});
$(".LayerLink").click(function () {
var $tree2 = $("#tree2");
var layerId = parseInt($(this).attr("class").replace("LayerLink ", ""), 10);
var node = $tree2.tree('getNodeById', layerId);
if (node) {
$tree2.tree('openNode', node.parent, false);
$tree2.tree('selectNode', node);
DisplayFeature(null, null, layerId, FloodMapServerURL);

if ($("#chkChangeExtent").prop("checked")) {
SetMapExtent(node.parent.extent);
}
$(this).closest("table").find("tr.tblInfoWindowTrSelected").removeClass("tblInfoWindowTrSelected");
$(this).closest("tr").addClass("tblInfoWindowTrSelected");
}
});
}
});
}

QueryTask exixsts in the new version but IdentifyTask has been removed and the replacement is "esri/rest/identify". 

I used identify based on the sample https://codepen.io/pen?editors=1010 and rewrote the code got "promise" error. How can I write the code in Arcgis version 4.x? What is the replacements?

[UndralBatsukh]

Hi there, 

The link to your codepen is points to an empty codepen. In any case you can use the identify similar to what is shown below. 

const params = {
  geometry: event.mapPoint,
  tolerance: 3,
  mapExtent: view.extent
};

identify.identify("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer", params).then((results)=>{
   console.log(results);
});

Hope this helps,

-Undral