找不到HTTP / 1.1 404-向Rails路由的jQuery POST请求

Question

I have a custom route, in my Ruby on Rails 4 application, which handles post requests sent via jQuery through an onChange() function.

The destination URL is http://0.0.0.0:3000/application/get_programs_for_center

Here is my Rails controller which handles the POST request

 post '/application/get_programs_for_center', to: 'school_applications#get_programs_for_center'

And here is the jQuery which calls this route:

$("#school_application_fls_center").change(function(){
var center_id = document.getElementById("school_application_fls_center").value;
var formdata = {center: center_id}; 
$.ajax({
    url: "/application/get_programs_for_center",
    type: "POST",
    datatype: 'json',
    data: formdata,
    success: function(response){
      var options = $("#school_application_program"); 
      removeOptions(document.getElementById("school_application_program"));
      $.each(response.programs, function(i,item) {
        options.append($("<option />").val(response.programs[i].id).text(response.programs[i].name)); 
      });
    }
});
 });

It currently is working perfectly in Chrome, however in Safari, Firefox and Opera I am getting this 404 error:

Here is my controller code:

def get_programs_for_center
 respond_to do |format|
  @school_application = SchoolApplication.find(session[:current_app_id])
  @select_program = @school_application.program
  center = params[:center]
  programs = Program.where(fls_center_id: center)
  msg = { :programs => programs, :message => "hurray", :program => @select_program} 
  format.json  { render :json => msg } 
 end 

end

Answer 1

So I was getting the following error in my rails Server log, which was throwing the 404:

ActiveRecord::RecordNotFound (Couldn't find SchoolApplication without an ID):
app/controllers/school_applications_controller.rb:144:in `block in get_housing_options_for_center'
app/controllers/school_applications_controller.rb:137:in `get_housing_options_for_center'

And then was thrown because I was trying to grab a session var that hadn't be set (hence why it didn't work on all the other browsers seperate from Chrome, which had the session var stored as I had been doing most of my development through that browser).

 @school_application = SchoolApplication.find(session[:current_app_id])

so that threw an error as the variable hadn't been set so I replaced it with this:

  if session[:current_app_id]
    @school_application = SchoolApplication.find(session[:current_app_id])
  else
    @school_application = SchoolApplication.new() 
    session[:current_app_id] = @school_application.id
  end

and I no longer get a 404.