Class: Checkpoint::Agent::Resolver

Inherits:
Object
  • Object
show all
Defined in:
lib/checkpoint/agent/resolver.rb

Overview

An Agent Resolver is the bridge between a concrete user (or other account/actor) and Checkpoint::Agents that the user represents.

There are two basic operations:

  • Conversion maps an actor to a single Agent

  • Expansion maps an actor to all of the Agents it represents

These allow credentials to be granted, matched, or revoked with the appropriate semantics, depending on the operation. In general, a Grant is given to or revoked from a single Agent, while matching is applied to all Agents the actor represents.

This implementation does not implement any expansion semantics other than to convert the actor into an Agent and return it as a list.

To extend the set of Checkpoint::Agents resolved, implement a subclass that returns an array of agents from #expand. This customized implementation would typically be injected to an application-wide Checkpoint::Authority, rather than being used directly.

For example, a custom resolver might add a group agent for each group that the user is a member of, or IP address-based geographical regions or organizational affiliations.

Instance Method Summary collapse

Instance Method Details

#convert(actor) ⇒ Agent

Default conversion from an actor to an Checkpoint::Agent.

If the actor implements #to_agent, we will delegate to it. Otherwise, we will instantiate an Checkpoint::Agent with the supplied actor.

Override this method to use a different or conditional Agent type.

Returns:

  • (Agent) —

    the actor converted to an agent



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# File 'lib/checkpoint/agent/resolver.rb', line 54

def convert(actor)
  if actor.respond_to?(:to_agent)
    actor.to_agent
  else
    Agent.new(actor)
  end
end

#expand(actor) ⇒ Agent

Expand an actor to a list of Agents it represents.

This implementation simply converts the actor and wraps the resulting Agent in an array.

If extending or overriding, you will likely want to call super or #convert on the concrete actor to make sure that the most specific Agent is included. It is acceptable to return subclasses of Agent, though that is generally unnecessary because of its design of delegating to actor methods.

Returns:

  • (Agent) —

    an array of agents for this actor



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# File 'lib/checkpoint/agent/resolver.rb', line 42

def expand(actor)
  [convert(actor)]
end