Accounts (multi-server)

Documentation of how to use the Accounts client to connect to other servers.

The accounts-base package exports two constructors, called AccountsClient and AccountsServer, which are used to create the Accounts object that is available on the client and the server, respectively.

This predefined Accounts object (along with similar convenience methods of Meteor, such as Meteor.logout) is sufficient to implement most accounts-related logic in Meteor apps. Nevertheless, these two constructors can be instantiated more than once, to create multiple independent connections between different accounts servers and their clients, in more complicated authentication situations.

Anywhere
new AccountsCommon(options)
import { AccountsCommon } from 'meteor/accounts-base' (accounts-base/accounts_common.js, line 1)

Super-constructor for AccountsClient and AccountsServer.

The AccountsClient and AccountsServer classes share a common superclass, AccountsCommon. Methods defined on AccountsCommon.prototype will be available on both the client and the server, via the predefined Accounts object (most common) or any custom accountsClientOrServer object created using the AccountsClient or AccountsServer constructors (less common).

Here are a few of those methods:

Anywhere but publish functions
AccountsCommon#userId()

Get the current user id, or null if no user is logged in. A reactive data source.

Anywhere but publish functions
AccountsCommon#user()

Get the current user record, or null if no user is logged in. A reactive data source.

Anywhere
AccountsCommon#config(options)

Set global accounts options.

Options

sendVerificationEmail Boolean

New users with an email address will receive an address verification email.

forbidClientAccountCreation Boolean

Calls to createUser from the client will be rejected. In addition, if you are using accounts-ui, the "Create account" link will not be available.

restrictCreationByEmailDomain String or Function

If set to a string, only allows new users if the domain part of their email address matches the string. If set to a function, only allows new users if the function returns true. The function is passed the full email address of the proposed new user. Works with password-based sign-in and external services that expose email addresses (Google, Facebook, GitHub). All existing users still can log in after enabling this option. Example: Accounts.config({ restrictCreationByEmailDomain: 'school.edu' }).

loginExpirationInDays Number

The number of days from when a user logs in until their token expires and they are logged out. Defaults to 90. Set to null to disable login expiration.

oauthSecretKey String

When using the oauth-encryption package, the 16 byte key using to encrypt sensitive account credentials in the database, encoded in base64. This option may only be specifed on the server. See packages/oauth-encryption/README.md for details.

Anywhere
AccountsCommon#onLogin(func)

Register a callback to be called after a login attempt succeeds.

Arguments

func Function

The callback to be called when login is successful.

See description of AccountsCommon#onLoginFailure for details.

Anywhere
AccountsCommon#onLoginFailure(func)

Register a callback to be called after a login attempt fails.

Arguments

func Function

The callback to be called after the login has failed.

Either the onLogin or the onLoginFailure callbacks will be called for each login attempt. The onLogin callbacks are called after the user has been successfully logged in. The onLoginFailure callbacks are called after a login attempt is denied.

These functions return an object with a single method, stop. Calling stop() unregisters the callback.

On the server, the callbacks get a single argument, the same attempt info object as validateLoginAttempt. On the client, no arguments are passed.

Anywhere
AccountsCommon#onLogout(func)

Register a callback to be called after a logout attempt succeeds.

Arguments

func Function

The callback to be called when logout is successful.

Client
new AccountsClient(options)
import { AccountsClient } from 'meteor/accounts-base' (accounts-base/accounts_client.js, line 3)

Constructor for the Accounts object on the client.

Options

connection Object

Optional DDP connection to reuse.

ddpUrl String

Optional URL for creating a new DDP connection.

At most one of options.connection and options.ddpUrl should be provided in any instantiation of AccountsClient. If neither is provided, Meteor.connection will be used as the .connection property of the AccountsClient instance.

Note that AccountsClient is currently available only on the client, due to its use of browser APIs such as window.localStorage. In principle, though, it might make sense to establish a client connection from one server to another remote accounts server. Please let us know if you find yourself needing this server-to-server functionality.

These methods are defined on AccountsClient.prototype, and are thus available only on the client:

Client
AccountsClient#loggingIn()

True if a login method (such as Meteor.loginWithPassword, Meteor.loginWithFacebook, or Accounts.createUser) is currently in progress. A reactive data source.

Client
AccountsClient#logout([callback])

Log the user out.

Arguments

callback Function

Optional callback. Called with no arguments on success, or with a single Error argument on failure.

Client
AccountsClient#logoutOtherClients([callback])

Log out other clients logged in as the current user, but does not log out the client that calls this function.

Arguments

callback Function

Optional callback. Called with no arguments on success, or with a single Error argument on failure.

Server
new AccountsServer(server)
import { AccountsServer } from 'meteor/accounts-base' (accounts-base/accounts_server.js, line 5)

Constructor for the Accounts namespace on the server.

Arguments

server Object

A server object such as Meteor.server.

These methods are defined on AccountsServer.prototype, and are thus available only on the server:

Server
AccountsServer#validateNewUser(func)

Set restrictions on new user creation.

Arguments

func Function

Called whenever a new user is created. Takes the new user object, and returns true to allow the creation or false to abort.

This can be called multiple times. If any of the functions return false or throw an error, the new user creation is aborted. To set a specific error message (which will be displayed by accounts-ui), throw a new Meteor.Error.

Example:

// Validate username, sending a specific error message on failure.
Accounts.validateNewUser(function (user) {
  if (user.username && user.username.length >= 3)
    return true;
  throw new Meteor.Error(403, "Username must have at least 3 characters");
});
// Validate username, without a specific error message.
Accounts.validateNewUser(function (user) {
  return user.username !== "root";
});

If the user is being created as part of a login attempt from a client (eg, calling Accounts.createUser from the client, or logging in for the first time with an external service), these callbacks are called before the Accounts.validateLoginAttempt callbacks. If these callbacks succeed but those fail, the user will still be created but the connection will not be logged in as that user.

Server
AccountsServer#onCreateUser(func)

Customize new user creation.

Arguments

func Function

Called whenever a new user is created. Return the new user object, or throw an Error to abort the creation.

Use this when you need to do more than simply accept or reject new user creation. With this function you can programatically control the contents of new user documents.

The function you pass will be called with two arguments: options and user. The options argument comes from Accounts.createUser for password-based users or from an external service login flow. options may come from an untrusted client so make sure to validate any values you read from it. The user argument is created on the server and contains a proposed user object with all the automatically generated fields required for the user to log in, including the _id.

The function should return the user document (either the one passed in or a newly-created object) with whatever modifications are desired. The returned document is inserted directly into the Meteor.users collection.

The default create user function simply copies options.profile into the new user document. Calling onCreateUser overrides the default hook. This can only be called once.

Example:

// Support for playing D&D: Roll 3d6 for dexterity
Accounts.onCreateUser(function(options, user) {
  var d6 = function () { return Math.floor(Random.fraction() * 6) + 1; };
  user.dexterity = d6() + d6() + d6();
  // We still want the default hook's 'profile' behavior.

  if (options.profile)
    user.profile = options.profile;
  return user;
});

Server
AccountsServer#validateLoginAttempt(func)

Validate login attempts.

Arguments

func Function

Called whenever a login is attempted (either successful or unsuccessful). A login can be aborted by returning a falsy value or throwing an exception.

Call validateLoginAttempt with a callback to be called on login attempts. It returns an object with a single method, stop. Calling stop() unregisters the callback.

When a login attempt is made, the registered validate login callbacks are called with a single argument, the attempt info object:

typeString

The service name, such as “password” or “twitter”.

allowedBoolean

Whether this login is allowed and will be successful (if not aborted by any of the validateLoginAttempt callbacks). False if the login will not succeed (for example, an invalid password or the login was aborted by a previous validateLoginAttempt callback).

errorException

When allowed is false, the exception describing why the login failed. It will be a Meteor.Error for failures reported to the user (such as invalid password), and can be a another kind of exception for internal errors.

userObject

When it is known which user was attempting to login, the Meteor user object. This will always be present for successful logins.

connectionObject

The connection object the request came in on. See Meteor.onConnection for details.

methodNameString

The name of the Meteor method being used to login.

methodArgumentsArray

An array of the arguments passed to the login method.

A validate login callback must return a truthy value for the login to proceed. If the callback returns a falsy value or throws an exception, the login is aborted. Throwing a Meteor.Error will report the error reason to the user.

All registered validate login callbacks are called, even if one of the callbacks aborts the login. The later callbacks will see the allowed field set to false since the login will now not be successful. This allows later callbacks to override an error from a previous callback; for example, you could override the “Incorrect password” error with a different message.

Validate login callbacks that aren’t explicitly trying to override a previous error generally have no need to run if the attempt has already been determined to fail, and should start with

if (!attempt.allowed)
  return false;

Rate Limiting

By default, there are rules added to the DDPRateLimiter that rate limit logins, new user registration and password reset calls to a limit of 5 requests per 10 seconds per session. These are a basic solution to dictionary attacks where a malicious user attempts to guess the passwords of legitimate users by attempting all possible passwords.

These rate limiting rules can be removed by calling Accounts.removeDefaultRateLimit(). Please see the DDPRateLimiter docs for more information.

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Licensed under the MIT License.
https://docs.meteor.com/v1.3.5/api/accounts-multi.html