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logical-permissions

This is a generic library that provides support for array-based permissions with logic gates such as AND and OR. You can register any kind of permission types such as roles and flags. The idea with this library is to be an ultra-flexible foundation that can be used by any framework. Supported PHP version is 5.6 or higher.

Getting started

Installation

composer require ordermind/logical-permissions

Usage

Register permission types

Permission types are used to check different kinds of conditions for access control, and the first thing to do is to create one of these and register it. Let's say, for example, that we want to determine access using the current user's roles. First you create a class that implements like this:

Now we have implemented the two required methods - getName() and checkPermission() - and created a simple example for checking a role for a user. The name of the permission type is going to be used later as a key in your permission tree, and the checkPermission() method is where you, in this case, check whether the current user has a role or not.

Once you have created a permission type you can register it like this:

Check access

Now everything is set and you can check the access for a user based on their roles:

Permission trees

In the previous example, we had a variable called that looked like this:

This is an example of a permission tree. A permission tree is a hierarchical combination of permissions that is evaluated in order to determine access for a specific action. Let's say for example that you want to restrict access for updating a user. You'd like only users with the role "admin" to be able to update any user, but users should also be able to update their own user data (or at least some of it). With the format that this library provides, these conditions could be expressed elegantly in a permission tree as such:

In this example role and flag are the evaluated permission types. For this example to work you will need to register the permission types 'role' and 'flag' according to the previous guide.

Bypassing access checks

This library also supports rules for bypassing access checks completely for superusers. In order to use this functionality you first need to create a class that implements like this:

Then you can register it like this:

From now on, every time you call the user with the id 1 will be exempted so that no matter what the permissions are, they will always be granted access. If you want to make exceptions, you can do so by adding 'NO_BYPASS' => TRUE to the first level of a permission tree. You can even use permissions as conditions for NO_BYPASS.

Examples:

Logic gates

Currently supported logic gates are NOT. You can put logic gates anywhere in a permission tree and nest them to your heart's content. All logic gates support only an array as their value, except the NOT gate which has special rules. If an array of values does not have a logic gate as its key, an OR gate will be assumed.

AND

A logic AND gate returns true if all of its children return true. Otherwise it returns false.

Examples:

NAND

A logic NAND gate returns true if one or more of its children returns false. Otherwise it returns false.

Examples:

OR

A logic OR gate returns true if one or more of its children returns true. Otherwise it returns false.

Examples:

Shorthand OR

As previously mentioned, any array of values that doesn't have a logic gate as its key is interpreted as belonging to an OR gate.

In other words, this permission tree:

is interpreted exactly the same way as this permission tree:

NOR

A logic NOR gate returns true if all of its children returns false. Otherwise it returns false.

Examples:

XOR

A logic XOR gate returns true if one or more of its children returns true and one or more of its children returns false. Otherwise it returns false. An XOR gate requires a minimum of two elements in its value array.

Examples:

NOT

A logic NOT gate returns true if its child returns false, and vice versa. The NOT gate is special in that it supports either a string or an array with a single element as its value.

Examples:

Boolean Permissions

Boolean permissions are a special kind of permission. They can be used for allowing or disallowing access for everyone (except those with bypass access). They are not allowed as descendants to a permission type and they may not contain children. Both true booleans and booleans represented as uppercase strings are supported. Of course a simpler way to allow access to everyone is to not define any permissions at all for that action, but it might be nice sometimes to explicitly allow access for everyone.

Examples:

API Documentation

Table of Contents

• AccessChecker
  • setPermissionTypeCollection
  • getPermissionTypeCollection
  • setBypassAccessChecker
  • getBypassAccessChecker
  • getValidPermissionKeys
  • checkAccess
• PermissionTypeCollection
  • add
  • remove
  • has
  • get
  • toArray

AccessChecker

Checks access based on registered permission types, a permission tree and a context.

• Full name: \Ordermind\LogicalPermissions\AccessChecker
• This class implements: \Ordermind\LogicalPermissions\AccessCheckerInterface

setPermissionTypeCollection

Sets the permission type collection.

Parameters:

getPermissionTypeCollection

Gets the permission type collection.

setBypassAccessChecker

Sets the bypass access checker.

Parameters:

getBypassAccessChecker

Gets the bypass access checker.

getValidPermissionKeys

Gets all keys that can be used in a permission tree.

Return Value:

Valid permission keys.

checkAccess

Checks access for a permission tree.

Parameters:

Return Value:

TRUE if access is granted or FALSE if access is denied.

PermissionTypeCollection

Collection of permission types.

• Full name: \Ordermind\LogicalPermissions\PermissionTypeCollection
• This class implements: \Ordermind\LogicalPermissions\PermissionTypeCollectionInterface

add

Adds a permission type to the collection.

Parameters:

remove

Removes a permission type by name from the collection. If the permission type cannot be found in the collection, nothing happens.

Parameters:

has

Checks if a permission type exists in the collection.

Parameters:

get

Gets a permission type by name. If the permission type cannot be found, NULL is returned.

Parameters:

toArray

Returns a PHP array representation of this collection.