Backendless Login API

Description

Registered users can login using the API described below. The login operation requires two properties: one marked as user identity and the second is password. Backendless automatically assigns the "AuthenticatedUser" role to all successfully logged in users. The role can be used to differentiate access to various resources (data in the database, files, messaging channels) between authenticated users and guests.

Method

Non-Blocking API

The method call does not block - it returns immediately. The AsyncCallback argument receives either the response or the fault returned by the Backendless servers.

public void Backendless.UserService.login( String identity, 
                                           String password, 
                                           AsyncCallback<BackendlessUser> callback );

public void Backendless.UserService.login( String identity, 
                                           String password,   
                                           AsyncCallback<BackendlessUser> callback,
                                           boolean stayLoggedIn );

Blocking API

public BackendlessUser Backendless.UserService.login( String identity, 
                                                      String password, 
                                                      boolean stayLoggedIn ) 
                                                      throws BackendlessException;

where:

Argument	Description
identity	A value for a property marked as identity. String value.
password	User's password. String value.
callback	an object which receives either a return value or an error from the server. The class must implement the AsyncCallback<BackendlessUser> interface.
stayLoggedIn	Optional parameter. A boolean value requesting user login information to be saved so it can be reused when the application restarts (or page is reloaded).

Return Value

The BackendlessUser object representing the logged in user. The object has the values for all the properties stored in Users data table.

Example

The example below logs in as "alice@yourmail.com" using password "wonderland".

Non-Blocking API

// do not forget to call Backendless.initApp in the app initialization code

Backendless.UserService.login( "alice@yourmail.com", "wonderland", new AsyncCallback<BackendlessUser>()
{
 public void handleResponse( BackendlessUser user )
  {
    // user has been logged in
  }

  public void handleFault( BackendlessFault fault )
  {
    // login failed, to get the error code call fault.getCode()
  }
});

Blocking API

// do not forget to call Backendless.initApp in the app initialization code

BackendlessUser user;

try
{
  user = Backendless.UserService.login( "alice@yourmail.com", "wonderland" );
}
catch( BackendlessException exception )
{
  // login failed, to get the error code, call exception.getFault().getCode()
}

Errors

The following errors may occur during the Login API call. See the Error Handling section for details on how to retrieve the error code when the server returns an error.

Error Code	Description
2002	Version is disabled or provided wrong application info (application id or secret key)
3000	Login has been disabled for the user account.
3001	Missing login settings, possibly invalid application id or version.
3002	User cannot login because Multiple Logins disabled and there is a logged in user for the account.
3003	Invalid login or password.
3006	Either login or password is an empty string value.
3034	User logins are disabled for the version of the application.
3036	Account locked out due to too many failed logins.
3038	One of the required parameters (application id, version, login or password) is null
3044	Multiple login limit for the same user account has been reached.
8000	Property value exceeds the length limit

Codeless Reference

where:

Argument	Description
identity	Represents a value for the property marked as identity in the Users data table. Usually, the default is the user's email, which is used for the login operation.
password	User's password.
stay logged in	A boolean value requesting user login information to be saved so it can be reused when the application restarts (or page is reloaded).
return user	Optional parameter. When this option is checked, the operation returns the BackendlessUserobject containing user data.

Returns the BackendlessUser object representing the logged in user. The object has the values for all the properties stored in Users data table.

Consider the following record in the Users data table:

The example below logs in as "alice@wonderland.com" and returns the BackendlessUser object, since the return user option is checked.

The BackendlessUser object will look as shown below after the Codeless logic runs: