Adding a new BaaS method for executing a password reset email notification using Kinvey

A couple of days ago, I covered how to add password reset functionality to your application for resetting the password inside your app.
A common question I got was how to leverage the cloud based password reset email functionality that many BaaS providers offer. Today, I thought I would cover how to add password reset functionality via an email notification to your BaaS enabled mobile application using RAD Studio XE6. This tutorial uses Kinvey, but I am going to do a blog post on Parse soon as well.

This demo shows you how to derive from the existing Kinvey API class (TExtendKinveyAPI = class(TKinveyAPI)) for the Kinvey component and add a new method for executing Kinvey's password reset.

Inside your Kinvey.com account, go to AddOns->Messaging->Email Templates and customize your 'Password Reset' email template. There you can define Sender and Reply To information, the Subject line and the HTML for the body of your email. The App Name referenced in the email is the name of your application you defined inside your Kinvey.com account.



My application consists of 4 edit controls parented to 4 TListBox items:

• EditUsername


• EditPassword


• EditSessionToken


• EditEmail

TListBox has GroupingKind set to Grouped and StyleLookUp set to 'transparentlistboxstyle'.

I added the KinveyProvider1 component to my form and entered the AppKey, AppSecret and MasterSecret that is displayed inside my Kinvey.com account under 'AppName'->Manage Environments. In order to extend the functionality, I had to add a new method for triggering a password reset email notification which you can see in the code samples below.






Shown: Mobile app running on Windows with Mobile Preview style.

Here is the code for my ExtendKinveyApiUnit

unit ExtendKinveyApiUnit;



interface



uses REST.Backend.Kinveyapi, System.JSON, REST.Client, REST.Types;



type

  TExtendKinveyApi = class(TKinveyApi)

  private

  public

    procedure SignupUser(const AUserName, APassword, AEmail: string;

      out ALogin: TKinveyApi.TLogin); overload;

    procedure PasswordReset(const AEmail: string);

  end;



implementation



// New version of signup user that has a password parameter

procedure TExtendKinveyApi.SignupUser(const AUserName, APassword, AEmail: string;

  out ALogin: TKinveyApi.TLogin);

var

  LJSON: TJSONObject;

begin

  LJSON := TJSONObject.Create;

  try

    LJSON.AddPair('email', AEmail);

    inherited SignupUser(AUserName, APassword, LJSON, ALogin);

  finally

    LJSON.Free;

  end;

end;



//POST /rpc/:appKey/:email/user-password-reset-initiate HTTP/1.1

//Host: baas.kinvey.com

//Authorization: [Basic Auth with app credentials]

procedure TExtendKinveyApi.PasswordReset(const AEmail: string);

var

  LConnectionInfo: TConnectionInfo;

begin

  Request.ResetToDefaults;

  // Basic Auth

  LConnectionInfo := Self.ConnectionInfo;

  LConnectionInfo.UserName := AEmail;

  ConnectionInfo := LConnectionInfo;

  AddAuthParameter(TAuthentication.UserName);

  // App credentials

  AddAuthParameter(TAuthentication.AppSecret);

  Request.Method := TRESTRequestMethod.rmPOST;

  Request.Resource := 'rpc/{appkey}/{email}/user-password-reset-initiate';

  Request.AddParameter( 'email', AEmail, TRESTRequestParameterKind.pkURLSEGMENT );

  Request.Execute;

  CheckForResponseError([201]);

end;



end.

Here is the code for my mobile client

unit KinveyFormUnit;



interface



uses

  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,

  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, IPPeerClient,

  REST.OpenSSL, REST.Backend.KinveyProvider, FMX.StdCtrls,

  FMX.Edit, ExtendKinveyApiUnit, REST.Backend.ParseProvider, FMX.ListBox,

  FMX.Layouts, REST.Backend.ServiceTypes, REST.Backend.MetaTypes, System.JSON,

  REST.Backend.KinveyServices, REST.Backend.Providers,

  REST.Backend.ServiceComponents;



type

  TKinveyForm = class(TForm)

    EditUserName: TEdit;

    EditPassword: TEdit;

    ButtonSignup: TButton;

    EditEmail: TEdit;

    ButtonPasswordReset: TButton;

    EditSessionToken: TEdit;

    ToolBar1: TToolBar;

    Label5: TLabel;

    ListBox1: TListBox;

    UserLabel: TListBoxItem;

    PasswordLabel: TListBoxItem;

    EmailLabel: TListBoxItem;

    SessionLabel: TListBoxItem;

    KinveyProvider1: TKinveyProvider;

    procedure ButtonSignupClick(Sender: TObject);

    procedure ButtonPasswordResetClick(Sender: TObject);

    procedure FormCreate(Sender: TObject);



  private

    { Private declarations }

    FApi: TExtendKinveyAPI;

    procedure ClearFields;

  public

    { Public declarations }

  end;



var

  KinveyForm: TKinveyForm;



implementation



{$R *.fmx}



uses REST.Backend.KinveyApi;



procedure TKinveyForm.ButtonPasswordResetClick(Sender: TObject);

begin

  FApi.PasswordReset(EditEmail.Text);

  ShowMessage('Message sent to ' + EditEmail.Text);

end;



procedure TKinveyForm.ButtonSignupClick(Sender: TObject);

var

  LLogin: TKinveyAPI.TLogin;

begin

  FApi.SignupUser(EditUsername.Text, EditPassword.Text, EditEmail.Text, LLogin);

  FApi.Login(LLogin);  // Make subsequent calls as this user



  EditSessionToken.Text := LLogin.AuthToken;

  ShowMessage('Welcome ' + LLogin.User.UserName);

end;



procedure TKinveyForm.FormCreate(Sender: TObject);

begin

  FApi := TExtendKinveyAPI.Create(Self);

  KinveyProvider1.UpdateApi(FApi);

end;



procedure TKinveyForm.ClearFields;

begin

  EditUserName.Text := '';

  EditPassword.Text := '';

  EditEmail.Text := '';

  EditSessionToken.Text := '';



end;



end.

Below you see a screenshot of the email that I received after clicking on the 'Reset Password via Email' button inside my app:



After clicking on the automatically generated reset URL, you see a web based form where you can reset your password: