This is an example from the blog post: http://www.ngauthier.com/2011/09/using-exceptions-to-manage-control-flow.html.
Please fork it and show me what you would do!
This is an example from the blog post: http://www.ngauthier.com/2011/09/using-exceptions-to-manage-control-flow.html.
Please fork it and show me what you would do!
# This controller's job is to exchange twitter credentials for Shortmail credentials | |
class TwitterReverseAuthController < ApplicationController | |
# First, let's make our own subclass of RuntimeError | |
class Error < RuntimeError; end | |
def api_key_exchange | |
# Here are our required parameters. If any are missing we raise an error | |
screen_name = params.fetch(:screen_name) { raise Error.new('screen_name required') } | |
token = params.fetch(:oauth_token) { raise Error.new('oauth_token required') } | |
secret = params.fetch(:oauth_secret){ raise Error.new('oauth_secret required') } | |
# OK now let's authenticate that user. If we can't find a valid user, raise an error | |
@user = User.by_screen_name(screen_name).where( | |
:oauth_token => token, | |
:oauth_secret => secret | |
).first or raise Error.new('user not found') | |
# Now we'll build a device. I'm not catching an exception on create! here because | |
# It should never fail. (I.e. a failure is actually a 500 because we don't expect it) | |
@device = Device.find_or_create_by_token!( | |
params.slice(:token, :description).merge(:user_id => @user.id) | |
) | |
render :json => { :api_key => @device.api_key } | |
# Now I can simply catch any of my custom exceptions here | |
rescue Error => e | |
# And render their message back to the user | |
render :json => { :error => e.message }, :status => :unprocessable_entity | |
end | |
end |