Casbin Objection Adapter

• Installation
• Basic usage
• Advanced usage
  • Filtered policy loading

Installation

npm install casbin-objection-adapter --save

yarn add casbin-objection-adapter

pnpm add casbin-objection-adapter

Basic usage

See the Casbin adapters documentation for more information.

import Knex from "knex";
import { newEnforcer } from "casbin";
import { ObjectionAdapter } from "casbin-objection-adapter";

const knex = Knex({
  /* regular knex options */
});

// All configuration is optional
const adapter = await ObjectionAdapter.newAdapter(knex, {});

// Create the enforcer with the given model
const enforcer = await newEnforcer("basic_model.conf", adapter);

// Supports auto-save
// See: https://casbin.org/docs/en/adapters#autosave
enforcer.enableAutoSave(true);

// No need to save explicitly since auto-save is enabled
await enforcer.addPolicies([
  ["alice", "data1", "read"],
  ["bob", "data2", "write"],
]);

await enforcer.enforce("alice", "data1", "read"); // true
await enforcer.enforce("bob", "data1", "read"); // false

Advanced usage

The following options are available:

Option	Default value	Description
createTable	true	Whether or not to create the table when initialized.
modelClass	CasbinRule	The model to use when querying policies. You can override this if you would like to control the table name
logger	noop	An optional logger in case additional visiblity is needed into the adapter. The inteface should match console

Filtered policy loading

This adapter supports filtered policy loading as of v0.3.1.

Policies are filtered using the loadFilteredPolicy function on the enforcer. Note that loading a filtered policy clears the in memory policy data. This is a feature of Casbin and not this adapter.

Filter examples taken from casbin-pg-adapter

The filters take an object with keys refering to the ptype of the filter, and values containing an array of filter values.

Any empty string, undefined, or null value is ignored in the filter.

Plain strings (such as those used in the simple filter example below) are tested for simple equality. Strings prefixed with regex: or like: are tested using pattern matching.

Simple filter example:

await enforcer.loadFilteredPolicy({
  p: ["alice"],
  g: ["", "role:admin"],
});

Using the above filter, you will get:

• all records with ptype of p, and subject of admin
• and all records with ptype of g, and a second argument of admin

Complex filter example:

await enforcer.loadFilteredPolicy({
  p: ["regex:(role:.*)|(alice)"],
  g: ["", "like:role:%"],
});

Using the above filter you will get:

• all records with ptype of p, and subjects that match the regex (role:.*)|(alice)
• and all records with ptype of g, and a second argument that is like role:%