Infinite Lightning Data Table Scrolling using @wire decorator

datatable_wire.html

<template>
    <div> <span class="slds-badge slds-badge_inverse badge"> Total Records in Table - {totalRecords} </span> </div>
    <div style="height: 300px">
        <lightning-datatable key-field="empId" data={dataRow} columns={columns} enable-infinite-loading="true"
        onloadmore={loadMoreData} load-more-offset="20" 
         > </lightning-datatable>
    </div>
</template>

datatable_wire.js

import { LightningElement, track, wire } from 'lwc';
import wireCall from '@salesforce/apex/DataTableDemoController.wireCall';


const columns = [
    { label: 'Employee Name', fieldName: 'empName', type:"text" }, 
    { label: 'Phone', fieldName: 'empPhone' , type:'phone' },  
    { label: 'Email', fieldName: 'empEmail' , type: 'email'}, 
    { label: 'Website', fieldName: 'empWebsite', type:"url" } 
]; 

export default class Datatable_wire extends LightningElement {
    maxRows=1000;
    tableElement;
    @track dataRow; 
    @track totalRecords;
    columns = columns;

    @wire( wireCall, {recToReturn : 10} )
    wireMethodCallback({error,data}){
        console.log('Callout JS');
        console.log(data);
        if(data){
            this.dataRow = data;  
            this.totalRecords = data.length;
            console.log(data );
            console.log(this.dataRow );
        }
    }

    loadMoreData(event) {
        console.log('Load more JS made');
        //Display a spinner to signal that data is being loaded
        if(event.target){
            event.target.isLoading = true;
        }
        this.tableElement = event.target;
        //Display "Loading" when more data is being loaded
        this.loadMoreStatus = 'Loading';

        wireCall( {recToReturn : 10} )
            .then((data) => {
                console.log('Load more Call made');  
                    const currentData = this.dataRow;
                    //Appends new data to the end of the table
                    this.dataRow = this.dataRow.concat(data); 
                    this.loadMoreStatus = '';
                    this.totalRecords = this.dataRow.length; 
                    if (this.dataRow.length  >= this.maxRows) {
                        this.tableElement.enableInfiniteLoading = false;
                        this.loadMoreStatus = 'No more data to load';
                    }

                if(this.tableElement){
                    this.tableElement.isLoading = false;
                } 
            }
        );
    }
}

DataTableDemoController.cls

/**
 *  @desc   Apex Controller class for LWC Data Table Demo
 *  @Author Jitendra Zaa
 *  @Date   June 4 2020
 */
public with sharing class DataTableDemoController { 

    public class DataTableWrapper{
        @AuraEnabled
        public String empName;
        @AuraEnabled
        public String empEmail;
        @AuraEnabled
        public String empPhone;
        @AuraEnabled
        public String empWebsite;
        @AuraEnabled
        public String empId;
    }

    @AuraEnabled(cacheable=false)
    public static List<DataTableWrapper>  imperativeCall(Integer recToReturn){
        return getRandomEmployees(recToReturn);
    }

    @AuraEnabled(cacheable=true)
    public static List<DataTableWrapper>  wireCall(Integer recToReturn){
        return getRandomEmployees(recToReturn);
    }


    private static  List<DataTableWrapper>  getRandomEmployees(Integer recToReturn){
        List<DataTableWrapper> lstRet = new List<DataTableWrapper>();
        for(Integer i=0;i<recToReturn;i++){
            DataTableWrapper obj = new DataTableWrapper();
            obj.empId = DummyData_Generator.generateRandomString(18);
            obj.empName = DummyData_Generator.generateRandomString(15);
            obj.empEmail = DummyData_Generator.getRandomEmail();
            obj.empPhone = String.valueOf(DummyData_Generator.generateRandomNumber(10));
            obj.empWebsite = DummyData_Generator.generateRandomString(15)+'.com';
            lstRet.add(obj);
        }   
        return lstRet;
    }
}

DummyData_Generator.cls

/**
 *  @desc   Temporary class to generate Dummy data quickly
 *  @Author Jitendra Zaa
 *  @Date   June 4 2020
 */
public with sharing class DummyData_Generator {
 
    /**
     * @Description Generate random alpha numeric string of length X
     */
    public static String generateRandomAlphaNumeric(Integer len) {
        final String chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';
        String randStr = '';
        while (randStr.length() < len) {
           Integer idx = Math.mod(Math.abs(Crypto.getRandomInteger()), chars.length());
           randStr += chars.substring(idx, idx+1);
        }
        return randStr; 
    }

    /**
     * @Description Generate random alpha numeric string of length X
     */
    public static String generateRandomString(Integer len) {
        final String chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
        String randStr = '';
        while (randStr.length() < len) {
           Integer idx = Math.mod(Math.abs(Crypto.getRandomInteger()), chars.length());
           randStr += chars.substring(idx, idx+1);
        }
        return randStr; 
    }

    /**
     * @Description Generate random Number of length X
     */
    public static Decimal generateRandomNumber(Integer len) {
        final String chars = '0123456789';
        String randStr = '';
        while (randStr.length() < len) {
           Integer idx = Math.mod(Math.abs(Crypto.getRandomInteger()), chars.length());
           randStr += chars.substring(idx, idx+1);
        }
        return Decimal.valueOf(randStr); 
    }

    public static Integer generateRandomInteger(Integer len) {
        final String chars = '0123456789';
        String randStr = '';
        while (randStr.length() < len) {
           Integer idx = Math.mod(Math.abs(Crypto.getRandomInteger()), chars.length());
           randStr += chars.substring(idx, idx+1);
        }
        return Integer.valueOf(randStr); 
    }

    /**
     * @Description Generate random date in future
     */
    public static Date generateRandomDateInFuture(){
        Integer daysinFuture = generateRandomInteger(3);
        return Date.today().addDays(daysinFuture);
    }

    /**
     * @Description Generate random date in past
     */
    public static Date generateRandomDateInPast(){
        Integer daysinFuture = generateRandomInteger(3);
        return Date.today().addDays(-daysinFuture);
    }

    /**
     * @Description Generate random email address
     */
    public static String getRandomEmail(){
        return generateRandomString(10)+'@'+generateRandomString(5)+'.com';
    }

}