Ramaze::Helper::UserHelper

This helper provides a convenience wrapper for handling authentication and persistence of users.

On every request, when you use the {UserHelper#user} method for the first time, we confirm the authentication and store the returned object in the request.env, usually this will involve a request to your database.

@example Basic usage with User::authenticate

# We assume that User::[] will make a query and returns the requested
# User instance. This instance will be wrapped and cached.

class User
  def self.authenticate(creds)
    User[:name => creds['name'], :pass => creds['pass']]
  end
end

class Profiles < Ramaze::Controller
  helper :user

  def edit
    redirect_referrer unless logged_in?
    "Your profile is shown, your are logged in."
  end
end

class Accounts < Ramaze::Controller
  helper :user

  def login
    return unless request.post?
    user_login(request.subset(:name, :pass))
    redirect Profiles.r(:edit)
  end

  def logout
    user_logout
    redirect_referer
  end
end

On every request it checks authentication again and retrieves the model, we are not using a normal cache for this as it may lead to behaviour that is very hard to predict and debug.

You can however, add your own caching quite easily.

@example caching the authentication lookup with memcached

# Add the name of the cache you are going to use for the authentication
# and set all caches to use memcached

Ramaze::Cache.options do |cache|
  cache.names = [:session, :user]
  cache.default = Ramaze::Cache::MemCache
end

class User

  # Try to fetch the user from the cache, if that fails make a query.
  # We are using a ttl (time to live) of one hour, that's just to show
  # you how to do it and not necessary.
  def self.authenticate(credentials)
    cache = Ramaze::Cache.user

    if user = cache[credentials]
      return user
    elsif user = User[:name => creds['name'], :pass => creds['pass']]
      cache.store(credentials, user, :ttl => 3600)
    end
  end
end

@example Using a lambda instead of User::authenticate

# assumes all your controllers inherit from this one

class Controller < Ramaze::Controller
  trait :user_callback => lambda{|creds|
    User[:name => creds['name'], :pass => creds['pass']]
  }
end

@example Using a different model instead of User

# assumes all your controllers inherit from this one

class Controller < Ramaze::Controller
  trait :user_model => Account
end

@author manveru