Class: Pragma::Policy::Base Abstract

Inherits:
Object
  • Object
show all
Defined in:
lib/pragma/policy/base.rb

Overview

This class is abstract.

Subclass and implement action methods to create a policy.

This is the base policy class that all your record-specific policies should inherit from.

A policy provides predicate methods for determining whether a user can perform a specific action on a record.

Direct Known Subclasses

Pundit

Constant Summary collapse

Scope = 
::Pragma::Policy::Scope

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(user, record) ⇒ Base

Initializes the policy.

Parameters:

  • user (Object) —

    the user operating on the record

  • record (Object) —

    the record being operated on



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# File 'lib/pragma/policy/base.rb', line 26

def initialize(user, record)
  @user = user
  @record = record
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object

Provides bang form of predicates (create!, update! etc.).

Parameters:

  • method_name (String) —

    the method name

  • *args (Array<Object>) —

    the method arguments

Returns:

  • (Object) 


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# File 'lib/pragma/policy/base.rb', line 50

def method_missing(method_name, *args, &block)
  return super unless method_name[-1] == '!'
  authorize method_name[0..-2], *args
end

Instance Attribute Details

#record ⇒ Object (readonly)

Returns the value of attribute record.



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# File 'lib/pragma/policy/base.rb', line 19

attr_reader :user, :record

#user ⇒ Object (readonly) Also known as: context

Returns the user operating on the record.

Returns:

  • (Object) —

    the user operating on the record



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# File 'lib/pragma/policy/base.rb', line 19

def user
  @user
end

Instance Method Details

#authorize(action) ⇒ Object

Authorizes the user to perform the given action. If not authorized, raises a ForbiddenError.

Parameters:

  • action (Symbol) —

    the action to authorize

Raises:

  • (ArgumentError) —

    if the action is not defined in this policy

  • (ForbiddenError) —

    if the user is not authorized to perform the action



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# File 'lib/pragma/policy/base.rb', line 62

def authorize(action)
  unless respond_to?("#{action}?")
    fail(ArgumentError, "'#{action}' is not a valid action for this policy.")
  end

  return if send("#{action}?")

  fail(
    NotAuthorizedError,
    user: user,
    action: action,
    record: record
  )
end

#respond_to_missing?(method_name, include_private = false) ⇒ Boolean

Returns whether the policy responds to the provided missing method.

Supports bang forms of predicates (create!, update! etc.).

Parameters:

  • method_name (String) —

    the method name

  • include_private (Boolean) (defaults to: false) —

    whether to consider private methods

Returns:

  • (Boolean) 


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# File 'lib/pragma/policy/base.rb', line 39

def respond_to_missing?(method_name, include_private = false)
  return super unless method_name[-1] == '!'
  respond_to?("#{method_name[0..-2]}?", include_private) || super
end