Add api key to every request in ActiveResource

Question

I have 2 RESTful Rails apps I'm trying to make talk to each other. Both are written in Rails 3 (beta3 at the moment). The requests to the service will require the use an api key which is just a param that needs to be on every request. I can't seem to find any information on how to do this.

You define the url the resource connects to via the site= method. There should be an equivalent query_params= method or similar.

There is one good blog post I found related to this and it's from October 2008, so not exactly useful for Rails 3.

Update: I had a thought. Would a small Rack middleware or Metal be the answer to this? It could just pass through the request, tacking it's api_key on.

Answer 1

Use model#prefix_options which is a hash for passing params into query string (or even as substitions for parts of the Model.prefix, e.g. "/myresource/:param/" will be replaced by the value of prefix_options[:param] . Any hash keys not found in the prefix will be added to the query string, which is what we want in your case).

class Model < ActiveResource::Base
  class << self
    attr_accessor :api_key
  end

  def save
    prefix_options[:api_key] = self.class.api_key
    super
  end
end

Model.site = 'http://yoursite/'
Model.api_key = 'xyz123'
m = Model.new(:field_1 => 'value 1')
# hits http://yoursite:80/models.xml?api_key=xyz123
m.save

Answer 2

I recently was faced with a similar issue, if you are on Rails3, it supports using custom header which makes life much easier for these situations.

On the side you are making the request from, add

headers['app_key'] = 'Your_App_Key'

to the class you are inheriting from ActiveResource::Base

On you are server, for Authentication, simply receive it as

request.headers['HTTP_APP_KEY']

For Example:

class Magic < ActiveResource::Base
    headers['app_key'] = 'Your_App_Key'
end

now Magic.get, Magic.find, Magic.post will all send the app_key