ArcGIS map polygon store in ArcGIS

Question

I have to store the created polygon in ArcGIS. Once the polygon is stored in ArcGIS, it returns an ID (Object ID). With the object ID, the administrator can access the polygon in ArcGIS. I found a piece of code in one of our old systems the code is written in version 3xx.

function SendFeaturesToParent()
    {
        editingEnabled = false;
        editToolbar.deactivate();
        lyrMeters.clearSelection();

        polygon = currentEVT.graphic.geometry;

        var query = new Query();
        query.geometry = polygon;

        lyrAreas.applyEdits(null, [currentEVT.graphic], null);

        var attributes = [];
        var featureValues = [];
        for (var x = 0; x < selectedfeatures.length; x++) {
            featureValues.push("METER_ID: " + selectedfeatures[x].attributes["METER_ID"] + ", Type: " + selectedfeatures[x].attributes["Type"]);
            attributes.push(selectedfeatures[x].attributes);
        }
        console.log("attributes"+ attributes);
        //Send the array of meter values back to the parent page.
        var objectId = lyrAreas._defnExpr;
      objectId = objectId.split('=');
        window.parent.postMessage(
            {
                event_id: 'my_cors_message',
                data: attributes,
              objectId: objectId[1]
            }, 
            "*" //or "www.parentpage.com"
        ); 
        $('#modelConfirm').modal('hide');
    }

I need to implement in latest version of arcGIS API 4.23. What are the applyEdits do?

Answer 1

applyEdits method is the way you to add/update/delete features in a feature layer. Both version of the library have the method although in version 4 takes an object that contain the edits instead of the separated parameters. In your code, version 3, it is,

lyrAreas.applyEdits(null, [currentEVT.graphic], null);

first parameter is for new features, second for updates on features and third for features to delete.

While in version 4 it should be,

lyrAreas.applyEdits({
    updateFeatures: [currentEVT.graphic] /*updates*/
});

the object goes all the informations about the edits, in this case you only have updates.

I am not completely sure about this line,

var objectId = lyrAreas._defnExpr;
objectId = objectId.split('=');

I am guessing is the definition expression of the feature layer, a sql expression, that is why in the next line it is split, to use later the value. Version 3 library did not expose the property but gives set and get methods. Version 4 have the property and works in similar way. In this case for latest version it should be,

var objectId = lyrAreas.definitionExpression;
objectId = objectId.split('=');

So I do not think you will have

ArcGIS API v3 - FeatureLayer ArcGIS API v4 - FeatureLayer