save two models from on form does not work ruby radrails

Question

Hi, I'm a newbie with rad rails. I wanted to write at same time in two table from one form.

I have a table machine (with nom and role as column) and a table ipvfour (with machine_id and ip as column).

So I created in models the relation has-and-belongs-to-many.

But when I'm trying to add a new machine if failed with

unknown attribute: ip

I don't really understand why, can someone help me please ?

---

machine.controllers:

def create @machine = Machine.new(params[:machine])

ipvfour = @machine.ip.create(params[:ip])

respond_to do |format|

  if @machine.save && ipvfour.save

    flash[:notice] = 'Machine was successfully created.'

    format.html { redirect_to(@machine) }

    format.xml  { render :xml => @machine, :status => :created, :location => @machine }

else

format.html { render :action => "new" }

format.xml { render :xml => @machine.errors, :status => :unprocessable_entity }

end

end

end

---

new.html.erb (machine)

New machine

<% form_for(@machine) do |f_machine| %> <%= render :partial => 'form', :locals => { :f_machine => f_machine } %>

<%= f_machine.submit 'Create' %>

<% end %>

<%= link_to 'Back', machines_path %>

---

_form.html.erb (machine)

<%= f_machine.error_messages %>

<% f_machine.fields_for :ip do |f_ip| %> <%= render :partial => 'ipvfours/form', :locals => { :f_ip => f_ip } %>

<% end %>

---

_form.html.erb (ipvfours)

<%= f_ip.label :ip %><br /> <%= f_ip.text_field :ip %>

---

The page to add a machine is correclty displayed with all fields but it seems that write in db failed due to .... I hope that someone will be able ti help me.

Thanks in advance.

Answer 1

Hi,

EDIT:

You can edit any model in any controller if you want. There's a magic trick called accepts_nested_attributes_for (google it!)

Your code should look like:

In your Controller:

def new 
  # .... your code ....

  # create empty machine
  @machine  = Machine.new

  # add one empty ip 
  @machine.ipvfours.build

  # .... your code ....

end

def create 

  # fill machine and ipvfours directly 
  @machine = Machine.new(params[:machine])

  respond_to do |format|

    if @machine.save

      flash[:notice] = 'Machine was successfully created.'

      format.html { redirect_to(@machine) }

      format.xml  { render :xml => @machine, :status => :created, :location => @machine }

    else

      format.html { render :action => "new" }

      format.xml { render :xml => @machine.errors, :status => :unprocessable_entity }

    end

  end

end

In your view:

new.html.erb

<% form_for(@machine) do |f_machine| %>  

  <%= render :partial => 'form', :locals => { :f_machine => f_machine } %>

  <%= f_machine.submit 'Create' %>

<% end %>

<%= link_to 'Back', machines_path %>

_form.html.erb (machine)

<%= f_machine.error_messages %>

<% f_machine.fields_for :ipvfours do |f_ip| %> 
  <%= render :partial => 'ipvfours/form', :locals => { :f_ip => f_ip } %>
<% end %>

_form.html.erb (ipvfours)

<%= f_ip.label :ip %>
<br />
<%= f_ip.text_field :ip %>

In your Model:

Machine model

class Machine < ActiveRecord::Base

    has_many :ipvfours, :dependent => :destroy
    accepts_nested_attributes_for :ipvfours

end

best regards

simon

Answer 2

I'm sorry I need again some helps. After have those two table I added a new one: Owner.

This table contains only some people name. And I configured it as following:

Owner models

class Owner < ActiveRecord::Base
    has_many :machines, :dependent => :destroy
    accepts_nested_attributes_for :machines

    # resturn value for table in index page.
   def to_s
     "  #{name}"
   end
end

machines models

 class Machine < ActiveRecord::Base
    has_many :ipvfours, :dependent => :destroy
    belongs_to :owners
    accepts_nested_attributes_for :ipvfours
    accepts_nested_attributes_for :owners
 end

first thing is that in my table I do now see any owner and if I try to create new machine I have following error:

ActiveRecord::AssociationTypeMismatch in MachinesController#create

Owner(#60450264) expected, got Array(#35557212)

def new
    @machine = Machine.new
    @machine.owners.build
    @machine.ipvfours.build
    respond_to do |format|
      format.html # new.html.erb
      format.xml  { render :xml => @machine }
    end
 end

I don't understand as I think I correctly set has_one and belong_to

Thanks in advance