Easy implementation of nestedSortable with rails preserving the sort order http://mjsarfatti.com/sandbox/nestedSortable/

_page.html.slim

- class_for_root_only = ((root_ol rescue true) ? 'sortable' : @first_call = '')

ol class=class_for_root_only data-sort-url=sort_website_pages_path(@website)
  li id="list_#{page.id}"
    .handle
      = link_to page.name, edit_website_page_path(@website, page)
      ' 
      = active_icon(page, :published)
      .btn-group.pull-right
        = link_to t('View'), website_page_path(@website, page), :class => 'btn btn-mini'
        = link_to t('.edit', :default => t("helpers.links.edit")), edit_website_page_path(@website, page), :class => 'btn btn-mini'
        = link_to t('.destroy', :default => t("helpers.links.destroy")), website_page_path(@website, page), :method => :delete, :data => { :confirm => t('.confirm', :default => t("helpers.links.confirm", :default => 'Are you sure?'))}, :class => 'pull-right btn btn-mini btn-danger'
    - if page.children.size > 0
      = render :partial => 'page', :collection => page.children.order('position asc'), :locals => {:root_ol => false}

index.html.slim

  = render :partial => 'page', :collection => @pages

pages.coffee.js

save_page_list=(event, ui)->
  post_path = $(@).data('sort-url')
  
  arraied = $(@).nestedSortable('serialize', {'key': 'page_ids'} )
  
  $.post(post_path, arraied)

$('ol.sortable').nestedSortable({
  disableNesting:'no-nest',
  forcePlaceholderSize:true,
  handle:'div.handle',
  helper:	'clone',
  items:'li',
  maxLevels:5,
  opacity:.6,
  placeholder:'placeholder',
  revert:250,
  tabSize:25,
  tolerance:'pointer',
  toleranceElement:'>div',
  update: save_page_list,
})

pages_controller.rb

  def sort
    Page.transaction do
      pages_order = params[:page_ids].keys
      
      position = 10
      pages_hash = Page.find(pages_order).inject({}){|hash, page| hash[page.id.to_s] = page; hash}
      
      pages_order.each do |page_id|
        page = pages_hash[page_id]
        
        Rails.logger.debug("page #{page_id}")
        Rails.logger.debug("..moving to: #{params[:page_ids][page_id]}")
      
        if params[:page_ids][page_id] == 'null'
          page.move_to_root
        else
          page.parent_id = params[:page_ids][page_id].to_i
        end
        
        position = page.position = position + 10
        
        page.save
      end
    end
    
    render :nothing => true
  end