Creating Variable Number of Models in One Form (Page 2 of 7)

any idea why mine isn't posting any data to the database? i did freeze:edge yesterday. do i need some plug-in?
i got it to work by usign :url => {:action = "create" }
instead of the other thing

Last edited by pleatherrebel (2006-11-30 14:58:22)

I can't get to that page because the app is on a different machine, but in vendor/rails it says REVISION_5650

Now its working. Both with and without that line commented out. Oh well. Thanks for the thread. I have given up on figuring out variable number of text-fields forms.

Yeah, I imagine that is possible. If you pass the index of the fields you want to duplicate through the link_to_remote parameters, you can assign the new fields with the value of the old fields. Maybe something like this in RJS:

# after rendering the new partial
page["tasks[#{params[:index]}]_name"].value = "$('tasks[#{params[:source_index]}]_name').value"

Completely untested, but I think that will assign the value of the original task to the value of the new task you just created. There's probably a better way to do this, but at the moment I'm at a loss.

The hard part will be passing the new "index" parameter. Right now we update the link every time we add a task, but now each task will have a link, so it might become tricky to update every single link. At this point you might want to store the current index in the session so you can have access to it without passing the value back and forth.

I'm just kind of thinking out load here, so let me know if it doesn't make sense.

I'm assuming you mean validates_presence_of :page_id. Yes, this is a known problem as is mentioned in the thread you linked to. Unfortunately, it does not have a good work around. It may be fixed in 1.2 but I haven't done extensive testing.

Anyway, you may need to save the Paragraph models separately to avoid this error. I can probably post some code to do that if you need it.

In conclusion, if your task model :validates_presence_of :project_id, just add the following line:

def create
  @project = Project.new(params[:project])
  @project.save  # Add this line.  Voila!
  params[:tasks].each_value { |task| @project.tasks.build(task) }
  if @project.save
    redirect_to :action => 'index'
  else
    render :action => 'new'
  end
end

Not exactly rocket science but what can I say, I like the sound of my own voice.
Also: this would be easier to debug if the save method recorded failures in the log.  Oh well.

Hi Ryan, wonder if this thread is closed?
because I'm having an extended problem - How can I handle multiple dates? My challenge: I want to show a list of tasks together with their due_dates and I only want to be able to update the dates (with text_field and calendar helper) and on submit the modified dates (or all) shall be updated  - any suggestions highly appreciated..

Hello Ryan,

this tutorial saved my life since I am absolutly a newbie with ruby and rails and this article is exactly what I need for my project! But unfortanely there are two things I can't explain to myself:

First, in your example you put a first task into the project when creating a new one

@project.tasks.build # creates just one task

but this one never appears in my project. Even if I would try something like

10.times {@voucher.positions.build}

there is still no task ('position' in my case) until I add the first one. Do you (or anybody else) have an idea what the problem could be?

The second problem is that error which occurs on pushig the create button:

You have a nil object when you didn't expect it!
The error occurred while evaluating nil.each_value

def create
  @voucher = Voucher.new(params[:voucher])
    
  # vvv  the error occurs in this line  vvv
  params[:positions].each_value do |position|
    @voucher.positions.build(position) unless position.values.all?(&:blank?)
  end
  if @voucher.save
    flash[:notice] = 'Voucher was successfully created.'
    redirect_to :action => 'list'
  else
    render :action => 'new'
  end
end

This part is taken from the previous article and before I made the new changes it worked for me without any problems. It seems to me that any reference to params[:positions] is getting lost and I cant' figure out why. I have to say that my code is nearly the same as the one from this tutorial except for 'project' changed to 'voucher' and 'task' to 'position'.

I would really appreciate on any help or hint!

Thanks in advance

Not sure what the problem is, can you post the code you are using in the new.rhtml view? Specifically this area:

# in new.rhtml
<% @project.tasks.each_with_index do |task, index| %>
  <%= render :partial => 'task_fields', :locals => { :task => task, :index => index } %>
<% end %>

Make sure you aren't missing an equal sign when rendering the partial or something.