Protektor

Protektor is an isomorphic role based permission library that protects both UI resources and data models.

Install

From npm

npm install @555platform/protektor.ts

Defining Resource Data Model Mappings

The main feature of Protektor is enforcing permissions for both UI resources as well as related data models, therefore, defining resource data model mapping is the first step to initialize Proteckor. This step also gives Protektor list of all the resources to protect.

To define resource to data model name call:

import Protektor from 'protektor';

Protektor.resourceModels(resourceName, dataModel)

resourceName is a string identifying any resource you want to protect and typically this is some UI component or view. dataModel is a string or list of strings identifying data models needed to access information for the resource.

To retrieve data models for the resource call the same function but only with resourceName:

Protektor.resourceModels(resourceName)

This will return data model(s) associated with the given resource.

Define Role Identifier

Role identifier is an object that uniquely identifies the role. This object should contain all the relevant information to uniquely identify the role. Simplest example would be Role Identifier with just name:

{
  name: 'admin'
}

More complex Role Identifier could also store information about role groups. For example, maybe you need to have roles for your administrator team and default roles for other teams that are added automatically upon team creation. You could handle this by creating group field to differentiate between two admin roles:

admin role for administrator team:

{
  name: 'admin',
  group: 'system_administrators`
}

And for other teams:

Upon creation of each team the default admin role could be assigned:

{
  name: 'admin',
  group: 'default_team_roles'
}

Protektor needs to be able to search for the role identifier but it does not know what fields or combination of fields within role identifier makes it unique search criteria. In order to provide Protektor with this information you must register predicate that returns unique identity for the role. The predicate is a function with that takes role identifier object and returns unique id based on whatever algorithm you choose.

Using the last example above we could write our predicate to return the slug of name and group fields:

function roleId(roleIdentifier) {
  return slug(roleIdentifier.name + ' ' + roleIdentifier.group);
}

Protektor.registerRoleIdentifierPredicate(roleId)

Note that if you do not register role identifier predicate Protektor will scan role identifier object and concatinate values of object's all top level keys. Depending on your application this may be sufficient for you needs.

Define Permissions

To define access permissions within a role specify allowed action on the resource:

Protektor.allow({ action, resource, roleIdentifier })

or to disallow action explicitly:

Protektor.forbid({ action, resource, roleIdentifier })

You can also remove specific permission with:

Protektor.removePermission({ action, resource, roleIdentifier })

It is possible to call allow and then forbid on the same resource, action, role. The last call will overwrite permissions.

Remove Role

To remove entire role use removeRole API:

Protektor.removeRole(roleIdentifier)

Checking Permissions On The Server

Protektor library supports checking permissions for the given role on the server side via hasPermission API:

Protektor.hasPermission({ action, resource, roleIdentifier })

Returns true if permitted, otherwise false

On the server side you can also call hasModel API to verify that the given role has access to the data model you are trying to use:

Protektor.hasModel({ modelName, roleIdentifier })

Returns true if the specified model is accessible by the role, otherwise false

Sometimes it is useful to get the actual model object if the role permits the access. This can be accomplished with getModel API:

Protektor.getModel({ modelName, roleIdentifier, modelTransformCallback })

modelTransformCallback is a function that is called with modelName as parameter if the access to model is permitted or undefined if not permitted.

Searching For Roles On The Server

Protektor provides two APIs to search for roles. One to find a specific Role and second one to filter out roles based on some criteria.

To find specific role call Protektor.roleToJSON(RoleIdentifier). This will return role as JSON object that is ready to be marshalled to the client.

To find roles based on some criteria use Protektor.filterRoles(filterComparator, roleIdentifier). This function will return all roles that match criteria based on the filterComparator and value provided in roleIdentifier object.

For example let's assume you have roles defined like this:

[
  {
    name: 'role1'
  },
  {
    name: 'role2'
  },
  {
    name: 'role1',
    group: 'global'
  },
  {
    name: 'role2',
    group: 'global'
  }
]

and you want to just get the roles that belong to global group. You would call filterRoles as follows:

const globalRoles = await Protektor.filterRoles(
  roleIdentifier => roleIdentifier.group,
  {
    group: 'global'
  }
);

This would return only roles with group global:

[
  {
    name: 'role1',
    group: 'global'
  },
  {
    name: 'role2',
    group: 'global'
  }
]

Marshalling Role To The Client

To send a role with its permissions to the client call server side API: Protektor.roleToJSON(roleIdentifier).

Checking Permissions - ReactJS Client

Protektor provides hasPermission render prop component that will check permissions for the role. If the role is allowed to access to the resource children components will be rendered.

import { hasPermission, RoleBuilder } from 'protektor';

const currentRole = RoleBuilder.fromJSON(roleData);

.
.
.

<HasPermission to="read" access="Home" forRole={currentRole}>
  <SideNavSection
    to="/home"
    label="Home"
  />
</HasPermission>

Here RoleBuilder creates current user role from JSON. You will need to marshal the role from the server to client first.

RoleBuilder

RoleBuilder object is client side helper for unmarshalling JSON representation of Role that comes from the server. RoleBuilder returns client side representation of role described by Role object.

Client Role object

Client Role object is representation of the role defined on the server and it is used with all client APIs. It has the following APIs:

* roleIdentifier() - returns RoleIdentifier object as defined by developer
* hasPermission = ({ action, resource }) - returns true if action is allowed on resource, otherwise false

Protektor Storage

By default Protektor uses default memory store. Protektor storage can persist role and permission data to anywhere you want. protektor-data-adapter package provides base adapter class that you can use to extend.

import Protektor from 'protektor';
import { Adapter } from 'protektor-data-adapter';

class SomeNewAdapter extends Adapter {}
const someNewAdapter = new SomeNewAdapter();

.
.
.

Protektor.registerAdapter(someNewAdapter);