Angular Material: main service ts file for pagination sample

main.service.ts

import {Injectable} from '@angular/core';
import {HttpClient, HttpParams} from '@angular/common/http';

@Injectable()
export class MainService {
    constructor(protected http: HttpClient) {}
    
    private readonly baseUrl = "127.0.0.1:8000/api"; // here use your project's base url
    private additionalUrl = "/employees"; // here use your remaining route url
    protected _url = `${this.baseUrl}${this.additionalUrl}`;
    
    getAll(pageOffset: any, page, orderBy?): Observable<any> {
        const params = new HttpParams({
          fromObject: {pageOffset, page, orderBy}
        });
		
	return this.http.get(`${this._url}`, {params: params ? params : null});
    }
}