Question

How to make a selection(dropdown) search.I have 3 selection and when the user selects a dropdown the result div will reload to show results of the subjects.

Senario:

     select year | select semester | select course

    <div id="result">
     list of subjects base on the 3 selections
    </div>

Answer 1

I am not sure abt the code below working on rails 2.3 but it works on rails 3

$("#third_select_box_id").change ->
  first_select_box_data = $("#first_select_box_id").val()
  second_select_box_data = $("#second_select_box_id").val()
  third_select_box_data = $("#third_select_box_id").val()
  #add code to check that the first n second dropdown list have some data that has been    selected
  if (the data has been selected in all dropdown lists then )
    $.ajax
      type: "GET"
      data: "year="+first_select_box_data+"&semester="+second_select_box_data+"&course="+third_select_box_data
      url:"/courses/get_results"

If u want to display the data even if the year or semester isnt selected, dont do the checking in above coffeescript. In routes

resources: courses do
  get 'get_results'
end

in courses controller

def get_results
  @results = #ur logic to collect all results based on received params. Handle the condition that year or semester isnt selected(if u want to)
  respond_to do |format|
    format.js{}
  end
end

in get_results.js.haml

$("#result").html("#{escape_javascript(render :partial => 'results')}")

in _results.html.haml

#ur logic to display the @results

Do consider using datatables for listing as it will increase the performance.