tt-permissions

A strongly typed, serializable permissions system

Install

Download package

Grab the latest release from the Releases page. You want to download the tt-permissions.tgz file.

Add to project

To install the package we recommend copying it into a shared folder in your repo. Then you can install the local package with

yarn add tt-permissions@file:../packages/tt-permissions

Usage

The tt-permissions package is built on the core concepts of schemas, resources, actions and permission sets. A schema describes what possible resources exist. A resource can be anything in your application that needs managed access control. Actions include the standard Create Read Update Delete (CRUD) operations. A permission set is simply a set of granted actions on particular resources.

Import the required classes from tt-permissions

import { TTActions, TTPermissionSchema, TTResource } from '../src/tt_index'
import { TTPermissionSet } from '../src/tt_permission_set'

Define your resources.

class ResourceUser extends TTResource {}
class ResourceChannel extends TTResource {}
class ResourceInvite extends TTResource {}

Define your schema.

const schema = new TTPermissionSchema([
    ResourceUser,
    ResourceInvite,
    ResourceChannel
])

Now you can create a permission set.

const permissionSet = new TTPermissionSet(schema)
permissionSet.Grant(ResourceUser, TTActions.R)
permissionSet.Grant(ResourceChannel, TTActions.CRUD)

To get a serialized version of this permission set you can use ToString() This string can then be saved to the database and for example sent to the frontend to selectively show pages.

const permissionSetString = ps.ToString()

To get a permission set from a string you can use FromString(somePermissionSetString) This makes the package ideal for cases where you want to define permissions once and use it across the backend and frontend.

const anotherPermissionSet = new TTPermissionSet(schema)
anotherPermissionSet.FromString(permissionSetString)

Finally to query whether a certain action can be taken on a certain resource for a given permission set you can do :

if (permissionSet.Can(TTActions.C, ResourceInvite)) {
    console.log('I can create invites !!!')
}

if (permissionSet.Can(TTActions.UD, ResourceInvite) === false) {
    console.log('I can\'t update or delete invites !!!')
}