How to pass data from controller to view with ajax in rails

I posted today similar questions two times

how-to-use-local-or-instance-variable-in-ruby-code-in-coffeescript-in-haml-templ

ajax-in-rails-returns-alway-error-callback

I'm confusing about these issues please let me ask.

I'm using ajax in haml to reload a part of page with data from controller.

Please see my code.

.html.haml

= render 'layouts/partial' #This is partial. I want to reload this part

:coffee
    $('input#field').change ->
        $.ajax
            url: '/posts/gaga'
            type: "POST"
            dataType: 'text'
            error: (jqXHR, textStatus, errorThrown) ->
                alert "error"
            success: (data, textStatus, jqXHR) ->
                alert "success"
                $('div.kore').html('#{ j( render( 'layouts/partial' ) )} ');

posts_controller.rb

def gaga
    @model = Model.new("blabla")
    render :text => @model
end

_partial.html.haml

- if @model
    = @model.html_safe
- else
    = "No data"

First, I thought data can be get through @model instance variable from controller but it couldn't.

Second, I tryed to get data from ajax response data to view(_partial.html.haml) with jQuery.

Callback and response return correctly as text.

How do I pass data to view from ajax response data, or is there other ways?

Sorry for my sloppy English. I hope someone give me the clue.

Thanks in advance!