def new
    @project = Project.new
    @project.tasks.build # vytvoří jeden nový úkol
end


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


def add_task
    @task = Task.new
end

<% form_for :project, :url => { :action => 'create' } do |f| %>
    <p>Name: <%= f.text_field :name %></p>
    <h2>Tasks</h2>
    <div id="tasks">
        <% @project.tasks.each_with_index do |task, index| %>
            <%= render :partial => 'task_fields', :locals => { :task => task, :index => index } %>
        <% end %>
    </div>
    <%= render :partial => 'add_task_link', :locals => { :index => @project.tasks.size } %>
    <p><%= submit_tag 'Create Project' %></p>
<% end %>

<div id="task_<%= index %>">
    <% fileds_for "tasks[#{index}]", task do |f| %>
        <p><%= f.text_field :name %>
        <%= link_to_remote 'remove', :url => { :action => 'remove_task', :index => index } %>
        </p>
    <% end %>
</div>

page.insert_html :bottom, :tasks, :partial => 'task_fields', :locals => { :task => @task, :index => params[:index] }