Help needed to create a complex form

Rails
1

Hi
My models are message_thread, message, document (document with
attachments I am using paperclip)

message_thread

has_many messages

message

belongs_to message_thread
has_many :document_messages
has_many :documents, :through => :document_messages

document

has_attached_file :attachment,
:storage => :database
has_many :document_messages
has_many :messages, :through => :document_messages

 What i need is to create a message_thread with one message and that

message with 2(or more) attachments. I tried like

messages_controller

def new
@message_thread = MessageThread.new
@message = @message_thread.messages.build
end

new.html.erb

<%form_for @message_thread, :url => { :action => “create” },:html =>
{:multipart => true,:class => “mail-tenant”} do |f| %>

<%= f.text_field :mail_to %>



<% f.fields_for :messages do |message| %>
<%= message.label :subject,‘Subject’ %>
<%= message.text_field :subject,:maxlength => 255 %>



Attachments:


<% message.fields_for :documents do |document| %>

<%= document.file_field :attachment,:class => “file” %>
<%= document.hidden_field :company_id,:value =>
current_company.try(:id)%>

<%end%>
<%end%>


Send

Or Cancel


<%end%> 
       But I am getting error

ActiveRecord::AssociationTypeMismatch in MessagesController#create

Document(#-614356858) expected, got Array(#-608120208)

Please help me to solve this. I have a vague idea of using
accepts_nested_attributes_for . But please tell here can I use it

Thanks in advance

Tom

2

Hi,

There is an example for nested file upload form by using paperclip.
The codes are similar to you, be attention to the usage of
accepts_nested_attributes_for.

Check it here:
http://rails-bestpractices.com/posts/45-use-sti-and-polymorphic-model-for-multiple-uploads

3

Hi
Thanks for replying.I could do it partially with the following
modifications to my models and views

message_thread

has_many messages
accepts_nested_attributes_for :messages

message

belongs_to message_thread
has_many :document_messages
has_many :documents, :through => :document_messages
accepts_nested_attributes_for :documents,:reject_if => lambda {|a|
a[:attachment].blank?}
validates_presence_of :subject

  No other change. But the  problem is from the view I am not

selecting any file for upload and not entering values for ‘subject’ .
So surely the validation will fail and rerender my new action . My
‘create’ action like

def create
@message_thread = MessageThreads.new(params[:message_thread])
if @message_thread.save
flash[:notice] = “Message sent successfully”
redirect_to home_url
else
flash.now[:error] = @message_thread.errors.full_messages.join("
")
render :action => ‘new’
end
end

  The problem is now the file_field disappears. What might be the

cause?I am struggling with this for hours.Please help

Thanks

4

Hi,

Be sure you have build the document for message before you use it.