wash_out

WashOut

WashOut is a gem that greatly simplifies creation of SOAP service providers.

But if you have a chance, please http://stopsoap.com/.

Compatibility

Rails 4.0 and higher is tested. Code is known to work with earlier versions but we don't bother testing outdated versions anymore - give it a try if you are THAT unlucky.

Installation

In your Gemfile, add this line:

gem 'wash_out'

Please read release details if you are upgrading. We break backward compatibility between large ticks but you can expect it to be specified at release notes.

Usage

A SOAP endpoint in WashOut is simply a Rails controller which includes the module WashOut::SOAP. Each SOAP action corresponds to a certain controller method; this mapping, as well as the argument definition, is defined by soap_action method. Check the method documentation for complete info; here, only a few examples will be demonstrated.

# app/controllers/rumbas_controller.rb
class RumbasController < ApplicationController
  soap_service namespace: 'urn:WashOut'

  # Simple case
  soap_action "integer_to_string",
              :args   => :integer,
              :return => :string
  def integer_to_string
    render :soap => params[:value].to_s
  end

  soap_action "concat",
              :args   => { :a => :string, :b => :string },
              :return => :string
  def concat
    render :soap => (params[:a] + params[:b])
  end

  # Complex structures
  soap_action "AddCircle",
              :args   => { :circle => { :center => { :x => :integer,
                                                     :y => :integer },
                                        :radius => :double } },
              :return => nil, # [] for wash_out below 0.3.0
              :to     => :add_circle
  def add_circle
    circle = params[:circle]

    raise SOAPError, "radius is too small" if circle[:radius] < 3.0

    Circle.new(circle[:center][:x], circle[:center][:y], circle[:radius])

    render :soap => nil
  end

  # Arrays
  soap_action "integers_to_boolean",
              :args => { :data => [:integer] },
              :return => [:boolean]
  def integers_to_boolean
    render :soap => params[:data].map{|i| i > 0}
  end

  # Params from XML attributes;
  # e.g. for a request to the 'AddCircle' action:
  #   <soapenv:Envelope>
  #     <soapenv:Body>
  #       <AddCircle>
  #         <Circle radius="5.0">
  #           <Center x="10" y="12" />
  #         </Circle>
  #       </AddCircle>
  #     </soapenv:Body>
  #   </soapenv:Envelope>
  soap_action "AddCircle",
              :args   => { :circle => { :center => { :@x => :integer,
                                                     :@y => :integer },
                                        :@radius => :double } },
              :return => nil, # [] for wash_out below 0.3.0
              :to     => :add_circle
  def add_circle
    circle = params[:circle]
    Circle.new(circle[:center][:x], circle[:center][:y], circle[:radius])

    render :soap => nil
  end

  # With a customised input tag name, in case params are wrapped;
  # e.g. for a request to the 'IntegersToBoolean' action:
  #   <soapenv:Envelope>
  #     <soapenv:Body>
  #       <MyRequest>  <!-- not <IntegersToBoolean> -->
  #         <Data>...</Data>
  #       </MyRequest>
  #     </soapenv:Body>
  #   </soapenv:Envelope>
  soap_action "integers_to_boolean",
              :args => { :my_request => { :data => [:integer] } },
              :as => 'MyRequest',
              :return => [:boolean]

  # You can use all Rails features like filtering, too. A SOAP controller
  # is just like a normal controller with a special routing.
  before_filter :dump_parameters
  def dump_parameters
    Rails.logger.debug params.inspect
  end
  
  
  # Rendering SOAP headers
  soap_action "integer_to_header_string",
              :args   => :integer,
              :return => :string,
              :header_return => :string
  def integer_to_header_string
    render :soap => params[:value].to_s, :header => (params[:value]+1).to_s
  end
  
  # Reading SOAP Headers
  # This is different than normal SOAP params, because we don't specify the incoming format of the header,
  # but we can still access it through `soap_request.headers`.  Note that the values are all strings or hashes.
  soap_action "AddCircleWithHeaderRadius",
              :args   => { :circle => { :center => { :x => :integer,
                                                     :y => :integer } } },
              :return => nil, # [] for wash_out below 0.3.0
              :to     => :add_circle
  # e.g. for a request to the 'AddCircleWithHeaderRadius' action:
  #   <soapenv:Envelope>
  #     <soap:Header>
  #       <radius>12345</radius>
  #     </soap:Header>
  #     <soapenv:Body>
  #       <AddCircle>
  #         <Circle radius="5.0">
  #           <Center x="10" y="12" />
  #         </Circle>
  #       </AddCircle>
  #     </soapenv:Body>
  #   </soapenv:Envelope>
  def add_circle_with_header_radius
    circle = params[:circle]
    radius = soap_request.headers[:radius]
    raise SOAPError, "radius must be specified in the SOAP header" if radius.blank?
    radius = radius.to_f
    raise SOAPError, "radius is too small" if radius < 3.0

    Circle.new(circle[:center][:x], circle[:center][:y], radius)

    render :soap => nil
  end
  
end

# config/routes.rb
WashOutSample::Application.routes.draw do
  wash_out :rumbas
end

In such a setup, the generated WSDL may be queried at path /rumbas/wsdl. So, with a gem like Savon, a request can be done using this path:

require 'savon'

client = Savon::Client.new(wsdl: "http://localhost:3000/rumbas/wsdl")

client.operations # => [:integer_to_string, :concat, :add_circle]

result = client.call(:concat, message: { :a => "123", :b => "abc" })

# actual wash_out
result.to_hash # => {:concat_reponse => {:value=>"123abc"}}

# wash_out below 0.3.0 (and this is malformed response so please update)
result.to_hash # => {:value=>"123abc"}

Reusable types

Basic inline types definition is fast and furious for the simple cases. You have an option to describe SOAP types inside separate classes for the complex ones. Here's the way to do that:

class Fluffy < WashOut::Type
  map :universe => {
        :name => :string,
        :age  => :integer
      }
end

class FluffyContainer < WashOut::Type
  type_name 'fluffy_con'
  map :fluffy => Fluffy
end

To use defined type inside your inline declaration, pass the class instead of type symbol (:fluffy => Fluffy).

Note that WashOut extends the ActiveRecord so every model you use is already a WashOut::Type and can be used inside your interface declarations.

WSSE Authentication

WashOut provides two mechanism for WSSE Authentication.

Static Authentication

You can configure the service to validate against a username and password with the following configuration:

soap_service namespace: "wash_out", wsse_username: "username", wsse_password: "password"

With this mechanism, all the actions in the controller will be authenticated against the specified username and password. If you need to authenticate different users, you can use the dynamic mechanism described below.

Dynamic Authentication

Dynamic authentication allows you to process the username and password any way you want, with the most common case being authenticating against a database. The configuration option for this mechanism is called wsse_auth_callback:

soap_service namespace: "wash_out", wsse_auth_callback: ->(username, password) {
  return !User.find_by(username: username).authenticate(password).blank?
}

Keep in mind that the password may already be hashed by the SOAP client, so you would have to check against that condition too as per spec

Configuration

Use config.wash_out... inside your environment configuration to setup WashOut globally. To override the values on a specific controller just add an override as part of the arguments to the soap_service method.

Available properties are:

• parser: XML parser to use – :rexml or :nokogiri. The first one is default but the latter is much faster. Be sure to add gem nokogiri if you want to use it.
• wsdl_style: sets WSDL style. Supported values are: 'document' and 'rpc'.
• catch_xml_errors: intercept Rails parsing exceptions to return correct XML response for corrupt XML input. Default is false.
• namespace: SOAP namespace to use. Default is urn:WashOut.
• snakecase_input: Determines if WashOut should modify parameters keys to snakecase. Default is false.
• camelize_wsdl: Determines if WashOut should camelize types within WSDL and responses. Supports true for CamelCase and :lower for camelCase. Default is false.

Camelization

Note that WSDL camelization will affect method names but only if they were given as a symbol:

soap_action :foo  # this will be affected
soap_action "foo" # this will be passed as is

Maintainers

• Boris Staal, @inossidabile

Contributors (in random order)

• Mikael Henriksson, @mhenrixon
• Björn Nilsson @Bjorn-Nilsson
• Tobias Bielohlawek @rngtng
• Francesco Negri @dhinus
• Edgars Beigarts @ebeigarts
• Exad @wknechtel and @☈king
• Mark Goris @gorism
• ... and others

License

It is free software, and may be redistributed under the terms of MIT license.