tracks/app/views/todos/edit.js.erb

<%- object_name = unique_object_name_for("edit_todo_#{@todo.id}") %>

function add_spec(id, spec) {
  <%- 
    # do this outside of object_name to fill spec_of_todo in 
    # global namespace, not in namespace of object. Otherwise 
    # spec_of_todo is not available for the js attached to the 
    # edit form
  -%>
  spec_of_todo[id] = spec;
}

var <%=object_name%> = {
  animate: function() {
    <%=object_name%>.hide_todo();
    <%=object_name%>.replace_placeholder_with_form();
    <%=object_name%>.fill_dependency_array();
    enable_rich_interaction();
  },
  hide_todo: function() {
    $('#<%= dom_id(@todo, 'line') %>').hide();
  },
  replace_placeholder_with_form: function() {
    $('#<%=dom_id(@todo, 'edit')%>').html(<%=object_name%>.html_for_edit_form());
    $('#<%=dom_id(@todo, 'edit')%>').show();
    $('#<%=dom_id(@todo, 'form')%> input#todo_description').focus();
  },
  fill_dependency_array: function() {
    spec_of_todo = new Array();
    <%
    @todo.predecessors.each do |dep| -%>
      add_spec('<%=dep.id%>', "<%= escape_javascript(dep.specification)%>");
    <% end -%>
  },
  html_for_edit_form: function() {
    return "<%= js_render('todos/edit_form', {}, @todo) %>"
  }
}

<%=object_name%>.animate();