C#

This tutorial provides you with a step-by-step walkthrough of how to build a ‘Doctor’s Appointment App’ to send appointment reminders via SMS using Live Link 365.

This is not a production-ready application. Please take your time to enhance it for production so that it meets your specific business requirements.

The main panel on the right highlights the right piece of code for each step.

Steps

Create a class Person, since two of our entities share the same information, we are using this class to extend one of them, a patient will be treated as a person. Person will have the next attributes:

  • id: String
  • firstName: String
  • lastName: String
  • phoneNumber: String

Create a class Doctor and extend it from Person class, override the constructor to reflect the parameters needed for a Doctor. Doctor will have the same properties as Person and a new attribute:

  • specialization: Specialization

Create the class Specialization, that will have the next attributes:

  • id: String
  • name: String

Create the java class for Appointment using the Doctor, Patient, Specialization and Date class objects.

Create the getter/setter methods to access the attributes of the Appointment class

The properties.json file contains the information needed by the MessageHandler class in order to be able to send the SMS. It has three properties:

  • appKey
  • appSecret
  • defaultOrigin
Where appKey and appSecret are the ones generated for your app in the Live Link 365 Main Portal and defaultOrigin is the default number the message will be sent to

MessageHandler class works as a container for the functionalities required to send SMS through the API. For this step we have created two methods:

  • GetAccessToken(): This method will take the app Key and app Secret and combine them into a Base64 string, which will then be sent to the /api/oauth/token endpoint to generate and return the authentication token
  • sendMessage(): This method makes the POST request to the API to send the SMS; it receives the message to be sent, the number which we want to send the message, and optionally we can define from wich number we want to send the message

Now we finally call the main() function. Retrieve the information from properties.json to access the API data.

Create an instance of the MessageHandler class, passing the information we just retrieved.

Create the respective data needed, in our case, one specialization, one doctor, one patient and one appointment. NOTE: You can have a resources file to have more data and fetch these data.

Once an Appointment is created, we send the notification SMS to the patient where we let him/her known the details for the appointment (doctor and date of the appointment)

Code

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using System;
namespace appointmentReminder.Class
{

    // _Step_1
    public class Person
    {
        private String id;
        private String firstName;
        private String lastName;
        private String phoneNumber; //Phone numbers have to be in E.164 format.


        public Person()
        {
        }

        public Person(String id, String firstName, String lastName, String phoneNumber)
        {
            this.id = id;
            this.firstName = firstName;
            this.lastName = lastName;
            this.phoneNumber = phoneNumber;
        }

        public String getFullName()
        {
            return this.firstName + " " + this.lastName;
        }

        public String Id { get => id; set => id = value; }
        public String FirstName { get => firstName; set => firstName = value; }
        public String LastName { get => lastName; set => lastName = value; }
        public String PhoneNumber { get => phoneNumber; set => phoneNumber = value; }
    }
}

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using System;
namespace appointmentReminder.Class
{

    // _Step_2
    public class Doctor : Person
    {
        private Specialization specialization;

        public Specialization Specialization { get => specialization; set => specialization = value; }

        public Doctor()
        {
        }

        public Doctor(String id, String firstName, String lastName, Specialization specialization)
        {
            this.Id = id;
            this.FirstName = firstName;
            this.LastName = lastName;
            this.specialization = specialization;
        }
    }
}

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using System;
namespace appointmentReminder.Class
{
    // _Step_3
    public class Specialization
    {
        private Int32 id;
        private String name;

        public Specialization()
        {
        }

        public Specialization(Int32 id, String name)
        {
            this.id = id;
            this.name = name;
        }

        public Int32 Id { get => id; set => id = value; }
        public String Name { get => name; set => name = value; }
    }
}

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using System;

namespace appointmentReminder.Class
{
    // _Step_4
    public class Appointment
    {
        private Doctor doctor;
        private Person patient;
        private DateTime date;
        private Specialization specialization;

        public Appointment()
        {
        }

        public Appointment(Doctor doctor, Person patient, DateTime date)
        {
            this.doctor = doctor;
            this.patient = patient;
            this.date = date;
            this.specialization = doctor.Specialization;
        }

        public Doctor Doctor { get => doctor; set => doctor = value; }
        public Person Patient { get => patient; set => patient = value; }
        public DateTime Date { get => date; set => date = value; }
        public Specialization Specialization { get => specialization; set => specialization = value; }
    }
}

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/* _Step_5 */
{
    "appKey": "",
    "appSecret": "",
    "defaultOrigin": ""
}

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using System;
using System.Net;
using System.Text;
using Newtonsoft.Json;
using RestSharp;

namespace appointmentReminder.Class
{
    public class MessageHandler
    {
        private String baseUrl = "https://livelink.sapdigitalinterconnect.com/api";
        private String appKey;
        private String appSecret;
        private String defaultOrigin;
        private WebProxy globalProxy;

        public MessageHandler()
        {
        }

        public MessageHandler(String appKey, String appSecret, String defaultOrigin = "", WebProxy proxy = null)
        {
            this.appKey = appKey;
            this.appSecret = appSecret;
            this.defaultOrigin = defaultOrigin;
            this.globalProxy = proxy;
        }

        // _Step_6
        public String GetAccessToken()
        {
            String oAuthUrl = this.baseUrl + "/oauth/token";
            String bearer = Convert.ToBase64String(Encoding.UTF8.GetBytes(this.appKey + ":" + this.appSecret));
            RestClient client = new RestClient(oAuthUrl);
            if (this.globalProxy != null) {
                client.Proxy = this.globalProxy;
                client.Proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;
            }
            RestRequest request = new RestRequest(Method.POST);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddHeader("authorization", "Basic " + bearer);
            request.AddParameter("application/x-www-form-urlencoded", "grant_type=client_credentials", ParameterType.RequestBody);

            IRestResponse<oAuthToken> response = client.Execute<oAuthToken>(request);

            if (response.StatusCode != HttpStatusCode.OK) {
                Console.WriteLine("..... Error: " + response.StatusDescription);
                return "";
            }

            String accessToken = response.Data.access_token;
            return accessToken;
        }

        public void sendMessage(String message, String destination, String origin = "")
        {
            String messageUrl = this.baseUrl + "/v2/sms";
            Object messagePayload = new {
                message = message,
                origin =  origin == "" ? this.defaultOrigin : origin,
                destination = destination //Phone numbers have to be in E.164 format.
            };
            String messageData = JsonConvert.SerializeObject(messagePayload);
            String bearer = GetAccessToken();
            if (String.IsNullOrEmpty(bearer)) {
                return;
            }
            RestClient client = new RestClient(messageUrl);
            if (this.globalProxy != null) {
                client.Proxy = this.globalProxy;
                client.Proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;
            }

            RestRequest request = new RestRequest(Method.POST);
            request.AddHeader("authorization", "Bearer " + bearer);
            request.AddHeader("content-type", "application/json");
            request.AddParameter("application/json", messageData, ParameterType.RequestBody);

            IRestResponse response = client.Execute(request);

            if (response.StatusCode != HttpStatusCode.OK) {
                Console.WriteLine("..... failed to send message.");
                Console.WriteLine("..... Error: " + response.ErrorMessage);
            }
        }
    }
}

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using System;
using System.IO;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using appointmentReminder.Class;

namespace appointmentReminder
{
    class MainClass
    {

        // _Step_7
        public static void Main(string[] args)
        {
            JObject properties = JObject.Parse(File.ReadAllText(@"../../Resources/properties.json"));

            MessageHandler messageHandler = new MessageHandler(properties.GetValue("appKey").ToString(), properties.GetValue("appSecret").ToString(), properties.GetValue("defaultOrigin").ToString());

            Specialization cardio = new Specialization(1, "Cardiology");
            Doctor doctor = new Doctor("1", "Christina", "Yang", cardio);
            Person patient = new Person("2", "Steven", "Gorwell", "+2349092054");
            DateTime bookingDate = new DateTime(2018, 06, 18, 16, 0, 0);

            Appointment appointment = new Appointment(doctor, patient, bookingDate);

            String message = "Mr/Ms " + appointment.Patient.getFullName() + ", you have an appointment with Dr. " + appointment.Doctor.getFullName()
                                                   + "(" + appointment.Specialization.Name + ") scheduled on " + appointment.Date.ToString("D") + " at "
                                                   + appointment.Date.ToString("t");
            Console.WriteLine("Sending appointment reminder...");
            messageHandler.sendMessage(message, appointment.Patient.PhoneNumber);
        }
    }
}