Fire modal window and load contents from url

modal_remote

# VIEW where we have a link to fire modal. F.e., index.html.haml
# ...
= link_to "Edit form from modal", "#", title: "Title for modal window", data: { toggle: "modal", "load-url": edit_item(item), target: "#modalEditItem" }, class: "btn btn-sm btn-default"

# In the same view or corresponding JS asset
= content_for :scripts do
  :javascript
    $(document).ready(function(){
      $('#modalEditItem').on('show.bs.modal', function (e) {
        // load form (or other content) from remote url
        // to a .modal-body
        var loadurl = $(e.relatedTarget).data('load-url');
        
        // Change modal title
        var title   = $(e.relatedTarget).prop('title');
        
        // cnahge modal contents
        $(this).find('.modal-body').load(loadurl);
        $(this).find('.modal-title').html(title);
      });
    })

# Controller
def edit
  render layout: false
end

# edit.html.haml
= render "items/modal_form"

# _modal_form.html.haml
= form_for @resource, method: :put, remote: true do |f|
  .row
    .col-sm-4
      .form-group
        = f.label :quantity, class: ""
        = f.text_field :quantity, placeholder: Item.human_attribute_name(:quantity), class: "form-control"