ActiveModel and ActionMailer - ruby-on-rails

Question

Rails 3.1.2 with mail gem 2.3.0
I'm trying to use ActionMailer with an ActiveModel based form. I've defined my table less model like so:
class StprodApp
include ActiveModel::Validations
include ActiveModel::Conversion
extend ActiveModel::Naming
attr_accessor :email,:name
attr_reader :errors
validates_presence_of :email, :message => "Please enter your email address"
def initialize(attributes = {})
attributes.each do |name, value|
send("#{name}=", value)
end
#errors = ActiveModel::Errors.new(self)
end
def persisted?
false
end
end
So far so good, I can post a form based on stprod_app, and validations work
So now I want to send an email based off this model, so I do this in my create action:
#stprod_app = StprodApp.new(params[:stprod_app])
if #stprod_app.valid?
EmployeeMailer.stprod_app(#stprod_app).deliver
end
I get this error
undefined method `index' for #<StprodApp:0x007f95325a1ad0>
and this stack trace
mail (2.3.0) lib/mail/encodings.rb:117:in `value_decode'
mail (2.3.0) lib/mail/encodings.rb:101:in `decode_encode'
mail (2.3.0) lib/mail/fields/unstructured_field.rb:74:in `do_decode'
mail (2.3.0) lib/mail/fields/unstructured_field.rb:56:in `decoded'
mail (2.3.0) lib/mail/fields/unstructured_field.rb:107:in `wrapped_value'
mail (2.3.0) lib/mail/fields/unstructured_field.rb:70:in `do_encode'
mail (2.3.0) lib/mail/fields/unstructured_field.rb:52:in `encoded'
mail (2.3.0) lib/mail/field.rb:123:in `method_missing'
mail (2.3.0) lib/mail/header.rb:190:in `block in encoded'
mail (2.3.0) lib/mail/header.rb:189:in `each'
mail (2.3.0) lib/mail/header.rb:189:in `encoded'
mail (2.3.0) lib/mail/message.rb:1708:in `encoded'
actionmailer (3.1.2) lib/action_mailer/base.rb:451:in `set_payload_for_mail'
actionmailer (3.1.2) lib/action_mailer/base.rb:431:in `block in deliver_mail'
activesupport (3.1.2) lib/active_support/notifications.rb:53:in `block in
instrument'
activesupport (3.1.2) lib/active_support/notifications/instrumenter.rb:21:in
`instrument'
activesupport (3.1.2) lib/active_support/notifications.rb:53:in `instrument'
actionmailer (3.1.2) lib/action_mailer/base.rb:430:in `deliver_mail'
mail (2.3.0) lib/mail/message.rb:230:in `deliver'
app/controllers/stprod_app_controller.rb:20:in `create'
So I read the docs for the mail gem, and it says this:
---snip---
All objects that can render into an email, have an #encoded method. Encoded will return the object as a complete string ready to send in the mail system, that is, it will include the header field and value and CRLF at the end and wrapped as needed.
All objects that can render into an email, have a :decoded method. Decoded will return the object's "value" only as a string. This means it will not include the header fields (like 'To:' or 'Subject:').
By default, calling #to_s on a container object will call its encoded method, while #to_s on a field object will call it's decoded method. So calling #to_s on a Mail object will return the mail, all encoded ready to send, while calling #to_s on the From field or the body will return the decoded value of the object. The header object of Mail is considered a container. If you are in doubt, call #encoded, or #decoded explicitly, this is safer if you are not sure.
Structured fields that have parameter values that can be encoded (e.g. Content-Type) will provide decoded parameter values when you call the parameter names as methods against the object.
Structured fields that have parameter values that can be encoded (e.g. Content-Type) will provide encoded parameter values when you call the parameter names through the object.parameters[''] method call.
---snip---
It looks like the index error is Rail's last desperate attempt to decode/encode? the email. The only 'index' I found in rails that makes sense is in ActiveSupport::Multibyte::Chars.
It sounds like I have to implement an encode/decode method in my ActiveModel, but I can't figure out how!
Anybody know how to define an ActiveModel that works with ActionMailer?

Answer 1

Solved, left off a crucial detail, and therin lay the problem
I was passing the Stprod_app instance variable to the mail call:
def stprod_app(emp,app)
#app = app
#emp = emp
mail(:to=> #app.antibot,
:from=>#emp.email,
:app=>#app) # <<< DOH!!!!
Sorry!

Answer 2

I had a similar error from this code:
def report( request )
headers['environment'] = RAILS_ENV
headers['identifier'] = request.id
...
end
In this case, it could not encode request.id because it was numeric. Changing it to request.id.to_s solved the problem.